BIBLIOGRAPHY



VIRGINIA A. TAPAT, April 2012. Growth and Yield Performance of
Rice Varieties Grown under Two Moisture Regimes in Different Agro-
ecosystems.Benguet State University, La Trinidad, Benguet.
 
Adviser: Belinda A. Tad-awan, Ph.D.

ABSTRACT
 

The study aimed to compare the growth performance and grain yield of
different rice varieties under two moisture regimes in different agro-ecological
zones; to determine total water use efficiency of different rice varieties under two
moisture regimes in different agro-ecological zones; identify the best variety
under two moisture regimes in different agro-ecological zones; evaluate the
performance of rice varieties grown organically under two moisture regimes in a
mid mountain zone of Benguet; and correlate grain yield with growth parameters
of the rice varieties in the three sites.
Between the two soil moisture regimes, plants grown under aerobic
condition had lower yield and water use efficiency in the three locations. In
Lagangilang, Abra, the varieties were noted to have a lower grain yield per plot
and water use efficiency than in the flooded fields. In Luna, Apayao, a similar
trend was observed where lower grain yield of the varieties in aerobic condition
was obtained. Water use efficiency was similar in both conditions. Similarly in
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes 
in Different Agro‐ecosystems /Virginia A. Tapat. 2012 

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Kapangan, Benguet, grain yieldand water use efficiency were lower under aerobic
condition.

As to the varietal effect, in Lagangilang, Abra, NSIC Rc192 under aerobic
condition had the highest grain yield and water use efficiency while NSIC
Rc136Hhad the highest yield under flooded condition. In Luna, Apayao, the best
performer in terms of grain yield and water use efficiency under aerobic condition
was PSB Rc9 and NSIC Rc136H under flooded condition.Sapaw was the best
performer in Kapangan, Benguet under both aerobic and flooded conditions.

Thereexist varied interaction effect between the soil moisture regimes and
varieties in the different sites. In Lagangilang, Abra, plant height at physiological
maturity and filled grain ratio in the dry season were significantly affected by the
interaction of varieties and soil moisture regimes. In Luna, Apayao, there was a
significant interaction effect between the moisture regimes and the rice varieties
on plant height and filled grain ratio during the wet season. Likewise, a significant
interaction was observed on water use efficiency during the dry
season.InKapangan, Benguet, significant interaction was noted between the
moisture regimes and the rice varieties in terms of grain yield and number of
filled grains per panicle for both cropping seasons; on dry matter weight during
the August 2010-February 2011 cropping; and on total grain number per panicle,
filled grain ratio, 1000-grain weight, and water use efficiency during the March-
November 2011 cropping.
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes 
in Different Agro‐ecosystems /Virginia A. Tapat. 2012 

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Correlation analysis revealed a significant positive correlation between
harvest index and grain yield in Lagangilang, Abra under aerobic condition.
Panicle length, total and filled grain number per panicle havea significant positive
correlation with grain yield in Luna, Apayao. Plant height at maturity, number of
days from seeding to maturity, panicle length, total and filled grain per panicle,
and total dry matter weight have a significant positive correlation with grain yield
in Kapangan, Benguet under the same soil moisture regime. A significant
negative correlation existed on the total dry matter weight with grain yield in
Lagangilang, Abra; and on total tiller and panicle number at maturity with grain
yield in Kapangan, Benguet.

Under the flooded condition, a significant positive correlation occurred
between the total dry matter weight and harvest index with grain yield in
Kapangan, Benguet and a significant negative correlation between total tiller and
panicle number at maturity with grain yield in Luna, Apayao.

While most of the data gathered are conclusive, it is still recommended
that further studies maybe done to verify and confirm the results, particularly on
other drought tolerant and upland varieties in other locations.


Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes 
in Different Agro‐ecosystems /Virginia A. Tapat. 2012 

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INTRODUCTION



Background of the Study



Rice (Oryza sativa L.) is a staple food for over 70% of Asians, majority of
whom are below the poverty line (Bayot and Templeton, 2009).Rice receives 24-
30% of world’s developed fresh water and the biggest single ‘user” of such
resource (Boumanet al., 2007). It requirestwo to three times more water input
(rain and irrigation) per unit of grain produced than the major cereal crops, such
as wheat and maize (Tuonget al., 2005). In Asia, 90% of all freshwater is used to
irrigate crops, 50% of this for rice alone (Barker et al., 1999).
Under ideal condition and with good farm management, lowland rice in
the Philippines requires around 2,000 li of water to produce one kg of rice at 100
cavans per hectare yield (PhilRice, 2007). In most rice fields in the Philippines,
rice experts estimate that up to 4,000 li of water is usually used for a kg of rice.
Water resources have been increasingly getting scarce due to increasing
population, which demands more water for industrial and domestic uses.
Moreover, drought is currently experienced by various agricultural areas in the
Philippines. This means less water for farming, rice production in particular.
Therefore, there is pressure of producing more rice with less water. It has been
estimated that by 2025, 15 million ha of irrigated rice will suffer ‘physical water
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

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scarcity’, and most of the 22 million ha of irrigated rice grown in South and
Southeast Asia will suffer “economic water scarcity’ (Tuong and Bouman, 2002).
The aerobic rice production system is a welcome relief to the water-
limiting rice production condition. Its especially developed “aerobic rice”
varieties are grown in well-drained, non-puddled, and non-saturated soils (IRRI,
2010). Aerobic rice is not ponded and irrigated similar to other crops in water-
scarce environments, and can stand periodic flooding conditions (Castaneda et al.,
2004; Yang et al., 2005).
Previous studies on aerobic and other water conserving technologies were
undertaken in the vast rice areas of Tarlac, Nueva Ecija and Bulacan (Bayot and
Templeton, 2009).In the Cordillera, notwithstanding its small aggregated rice area
compared to other regions and in spite serving as the water cradle of adjacent
regions like Ilocos Region and Cagayan Valley, there is scarce information on
water conserving technologies. Rice farms are not even spared from the problem
of water scarcity.


Importance of the Study

The expected research result may provide Cordillera rice farmers relevant
information on how to adapt to water scarcity condition with the use of aerobic
rice production.

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Water requirement for aerobic rice is around 400-700 mm/season (Luoet
al., 2008) and is similar to the dry land crops, while it has higher economic value
(Boumanet al., 2002). Therefore, shifting gradually from traditional rice
production system to growing rice aerobically, especially in water-scarce irrigated
lowlands, can mitigate occurrence of water deficit problems. Growing aerobic rice
would likewise tremendously help not only to farmers but also to consumers who
will be faced with persistent high food (rice) prices if both yield and area continue
to decline.

Objectives of the Study


In general, the study was conducted to evaluate the growth and yield
performance of rice varieties grown under two moisture regimes in different agro-
ecological zones.
Specifically, this study aimed to:
1. compare the growthperformance and grain yield of different rice varieties
under two moisture regimes in three agro-ecological zones;
2. determine the water use efficiency of five rice varieties under two
moisture regimes in three agro-ecological zones;
3. identify the best variety under two moisture regimes in three agro-
ecological zones;

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4. evaluate the performance of rice varieties grown organically under two
moisture regimes in a high hills zone of Benguet; and
5. correlate grain yield with growth parameters of the rice varieties in the
three sites.

Place and Time of the Study

The field experimentswere in three sites for two cropping seasons (wet
and dry) and with varied months under each cropping season as follows:
1. In Lagangilang, Abra from July-November 2010 for wet cropping
season and December 2010-March 2011 for dry cropping season;
2. In Luna, Apayao from July-November 2010 for wet cropping season
and December 2010-March 2011 for dry cropping season; and
3. In Kapangan, Benguet from August 2010-February 2011 and March-
November 2011.

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REVIEW OF LITERATURE



Rice Water Balance



The water balance of a rice field consists of the inflows by irrigation,
rainfall and capillary rise; and the outflows by transpiration, evaporation,
overbund flow, seepage and percolation (Boumanet al., 2007).
Capillary rise is theupward movement of water from the groundwatertable.
In nonflooded (aerobic) soil, this capillaryrise may move into the root zone and
provide a cropwith extra water (Boumanet al., 2007). However, in flooded rice
fields,there is a continuous downward flow of water fromthe puddled layer to
below the plow pan that basically preventscapillary rise into the root zone.
Therefore, capillaryrise is usually neglected in the water balanceof rice
fields.When rainfall raises the level of ponded waterabove the height of bunds,
excess rain leaves therice field as surface runoff or overbund flow ((Boumanet al.,
2007).
Evaporation leaves the rice field directly fromthe ponded water layer.
Transpiration by rice plants withdraws water from the puddled layer ((Boumanet
al., 2007). Typical evapotranspiration rates of rice fields are 4–5 mm d–1 in the
wet season and 6–7 mm d–1 in the dry season, but can be as high as 10–11 mm d–1
in subtropical regions (Tabbalet al., 2002). During the crop growth period, about

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30–40% of evapotranspiration is evaporation (Boumanet al., 2005, Simpson et al.,
1992).
Seepage is the subsurface flow of waterunderneath the bunds of a rice
field. Percolation is the vertical flow of water to belowthe root zone.Water losses
by seepage and percolation account for about 25–50% of all water inputs in heavy
soils with shallow groundwater tables of 20–50-cm depth (Cabangonet al., 2004;
Dong et al., 2004), and 50–85% in coarse-textured soils with deep groundwater
tables of 1.5-m depth or more (Sharma et al., 2002, Singh et al., 2002).
It is the relatively large water flow by seepage, percolation, and
evaporation that makes lowland rice fields heavy “water users” (Boumanet al.,
2007). Total seasonal water input to rice fields (rainfall plus irrigation) can be up
to two to three times more for other cereals such as wheat or maize (Tuonget al.,
2005). Such flow varies from as little as 400 mm in heavy clay soils with shallow
groundwater tables (that directly supply water for crop transpiration) to more than
2,000 mm in coarse-textured (sandy or loamy) soils with deep groundwater tables
(Bouman and Tuong 2001, Cabangonet al., 2004). Around 1,300–1,500 mm is a
typical value for irrigated rice in Asia (Boumanet al., 2007).
The role of groundwater in providing water to rice plants may be large, but
has been neglected in most studies of the rice water balance. Recent data
collection suggests that through the (decade- to age-old) practice of continuous
flooding, the large amounts of percolating water have raised groundwater tables

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too close to the surface. With shallow groundwater, crop growth with a small
irrigation water supply can still be good because of the “hidden” water supply of
groundwater ((Boumanet al., 2007).

Water Productivity

Water productivity (WP) is a concept of partial productivityand denotes
the amount or value of product (rice grains) over volume or value of water used.
Total water productivity (WPTOT) is computed as weight of grains over
cumulative weight of all water inputs by irrigation, rain,and capillary rise
(Boumanet al.,2007).
Water productivity of rice with respect to total water input (irrigation plus
rainfall) ranges from 0.2 to 1.2 g grain kg–1 water, with 0.4 as the average value,
which is about half that of wheat (Tuonget al., 2005).

Target Environments for Aerobic System

Aerobic rice is a production system in which especially developed
“aerobic rice” varieties are grown in well-drained, non-puddled, and nonsaturated
soils (IRRI, 2010). Aerobic rice can be found or can be a suitable technology, in
the following areas: 1) “Favorable uplands”: areas where the land is flat, where
rainfall with or without supplemental irrigation is sufficient to frequently bring
the soil water content close to field capacity, and where farmers have access to

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external inputs such as fertilizers; 2) Fields on upper slopes or terraces in
undulating, rainfed lowlands. Quite often, soils in these areas are relatively
coarse-textured and well-drained, so that ponding of water occurs only briefly or
not at all during the growing season; and 3) Water-short irrigated lowlands: areas
where farmers do not have access to sufficient water anymore to keep rice fields
flooded for a substantial period of time (IRRI, 2009).


Yield Performance Relative to Management Practices

Varieties
It was reported that the following varieties: HD277, HD297 and HD502 in
China; Pusa Rice hybrid 10, Proagro611 hybrid, Pusa834 and IR55423-01 (Apo)
in India; PSB Rc 9 (Apo), UPLRi5, and PSB Rc80 in the Philippines are suitable
for aerobic rice production (Bayot and Templeton, 2009).
Belderet al., (2004) recommended that for future studies comparing
aerobic and flooded rice should include an elite lowland cultivar, bred for flooded
(well-watered) conditions. Such cultivar includes hybrid varieties. Accordingly,
this would enable a more accurate comparison of water use and yield under both
flooded and aerobic rice systems. In addition, aerobic rice varieties can yield 4-6
t/ha using significantly less input water than lowland rice (Bayot and Templeton,
2009).

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Soil Moisture Regimes
Huaqiet al., (2002) reported that in case studies conducted in northern
China, water use in aerobic rice system was about 60% less than that of lowland
rice, total water productivity 1.6-1.9 times higher, and net returns to water use two
times higher. Aerobic rice yields range from 4.5 to 6.5 tha-1. As earlier stated, this
is about twice higher than that of traditional upland varieties and 20-30% lower
than that of lowland varieties grown under flooded condition in China.
Castaneda et al., (2004) found that aerobic rice saved 73% of irrigation
water for land preparation and 56% during the crop growth stage. They further
concluded that the rice effectively used rainfall during the wet season. Aerobic
yields were lower by an average of 28% in the dry season and 20% lower in wet
season. Magat (a tropical hybrid) and Apo (a traditional upland inbred) showed
the highest yield between 5-6 tha-1 under aerobic condition.
Belderet al., (2005) reported that in their field experiments conducted in
the dry seasons of 2002 and 2003 in the Philippines, water use efficiency under
flooded condition was 36 and 41% lower than in aerobic plots in 2002 and 2003,
respectively. Apo cultivar grown under aerobic condition had attained yields of
6.3 and 4.2 t ha-1 in 2002 and 2003, respectively, and under flooded condition of
15 and 39% lower. In general, the difference in yield between aerobic and flooded
rice was greater in DS than in WS. This was associated with difference in the soil
water status of aerobic rice between DS and WS (Boumanet al., 2005). The soil

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was wetter in WS because of more frequent rains than in DS. The yield difference
between aerobic and flooded rice was attributed more to biomass production than
to harvest index. Among yield components, sink size (spikelets m2-1) contributed
more to the yield gap between aerobic and flooded rice than grain filling
percentage and 1000-grain weight. In general, flooded rice produced more
panicles with more spikelets per panicle than aerobic rice.
Boumanet al.,(2005) had grown different tropical upland and lowland rice
varieties under aerobic conditions during the six seasons in 2001-2003 at IRRI,
Los Banos, Laguna. Total water input was 1240-1880 mm in flooded fields and
790-1430 mm in aerobic fields. On the average, aerobic fields used 190 mm less
water in land preparation and had 250-300 mm less seepage and percolation, 80
mm less evaporation, and 25 mm less transpiration than flooded fields. The water
productivity of rice under aerobic conditions was 32-88% higher than under
flooded conditions. The highest yields under aerobic conditions were realized in
the dry season with the improved upland variety Apo (5.7 t ha-1) and the lowland
hybrid rice Magat (6 tha-1).
In an eight seasons study by Penget al., (2006), found that yield difference
between aerobic and flooded rice ranged from 8 to 69%, depending on the number
of seasons that aerobic rice has been continuously grown, the season and variety.
The yield difference between aerobic and flooded rice was attributed more to
difference in biomass production than to harvest index. Among the yield

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components, sink size (spikelets m2-1) contributed more to the yield gap between
aerobic and flooded rice than grain filling percentage and 1000-grain weight.
Yield decline was observed when aerobic rice was continuously grown and the
decline was greater in the dry season than in the wet season.

Seed Rate and Row Spacing
Experiments were conducted on seed rate and row spacing in China, seed
rate in India, and row spacing in the Philippines (Bayot and Templeton, 2009).
The findings of these experiments as follows: yields of dry-seeded aerobic rice
varieties (Apo in the Philippines and HD297 in China) are not very responsive to
row spacing between 25 cm to 35 cm or seed rates between 60 to 135 kgha-1. In
India, the yield of Pusa hybrid rice variety was unresponsive to seed rates between
40 and 80 kgha-1 but fell substantially when the seed rate was below 40 kgha-1 and
there was unresponsiveness to row spacing and seed rates of the varieties. These
results may provide farmers with some flexibility considering the fact that higher
seed rates may suppress weed growth, however, it will cost more.
Further, some initial management options and guidelines for aerobic rice
productionwere provided (Bayot and Templeton, 2009). It is suggested that before
seeding, the plot should be plowed and harrowed to obtain smooth seed beds.
Seeds can then be dry seeded at a depth of 1-2 cm in clay soils and 3-4 cm in
loamy soils. Alternatively, seedlings can be transplanted into saturated clay soils
that are kept wet for a few days after transplanting. While the experiments did not

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show that yields are responsive to seed rate or row spacing (within reason), it is
suggested that optimal seed rates are around 70-90 kgha-1 and row spacing could
be in the order of 25-35 cm (Bayot and Templeton, 2009). If grown in the dry
season, the prime irrigation recommendations are to apply 30 mm after sowing to
promote emergence and then, depending on rainfall quantity and pattern, irrigate
aroundflowering. As aerobic rice is not grown in permanently flooded soils,
weeds can be aproblem. To control weeds a pre- and/or post-emergence herbicide
(plus some manual ormechanical weeding) is recommended. Fertilizer
requirements will depend on the level ofnutrients already available to the crop.
Leaf colour charts (LCC) can be used to determinesite-specific nitrogen (N)
needs. In the absence of LCCs and the knowledge and skills in sitespecificnutrient
management, it is recommended that around 70-90 kg N/ha is a goodstarting point
– with adjustments made as necessary. The nitrogen should then be split intothree
applications. In the case of direct seeding, the first application should be applied
10-15 days after emergence, the second split at tillering and the third split at
panicle initiation. Itmay also be necessary to apply phosphorous (P) and zinc on
high pH soils.

Yield Components in Aerobic and Flooded Rice Production


In a two-cropping season-(2002-2003) experiment on crop performance,
nitrogen and water use of flooded and aerobic rice which was embedded in a

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long-term experiment in IRRI, Belderetal.,(2005) revealed that sink size,
represented by the number of grains m2-1, showed a strong response to N and
reflected LAI and biomass growth. Grain filling was significantly affected by
regime in both seasons and was below 77% in aerobic plots. In comparison,
around 90% of the grains were filled in 0-N flooded plots. Individual grain weight
showed slight but significant effect of N in 2002 and water regime in 2003.All
three components of yield were lower for aerobic than flooded conditions so that
there was no positive feed-back mechanism between yield components. They
inferredthat water deficit under aerobic cultivation lasted from around panicle
initiation until physiological maturity, and even lowering the threshold of re-
irrigation to -10 kPa around flowering still led to reduced grain filling. Flowering
in 2003 occurred shorter after the soil water potential reached -30 kPa than in
2002. They reasoned that stress might have caused the lower growth rate between
panicle initiation and flowering and the reduction in percentage grain filling and
individual grain weight as compared with 2002.
Penget al., (2006) pointed out that the yield difference between aerobic
and flooded rice was attributed more to difference in biomass production than to
harvest index. Among the yield components, sink size (spikeletsm2-1) contributed
more to the yield gap between aerobic and flooded rice than grain filling
percentage and 1000-grain weight.

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MATERIALS AND METHODS



Materials


Experimental Design and Treatments

The field experiment was laid-out using a split-plot design with four
replications with soil moisture regimes as the main plot and rice varieties as the
sub-plot.
Main Plot: Soil Moisture Regimes (M)
Subplot: Varieties (V)
M1
–
Aerobic
Lagangilang,Abra
and
Luna,Apayao:
M2
–
Flooded
V1 – NSIC Rc9





V2 - PSB Rc14





V3 – PSB Rc68





V4 – NSIC Rc136H





V5 – NSIC Rc192
Kapangan,
Benguet:
V1 – NSIC Rc9





V2 - PSB Rc14





V3 – PSB Rc68





V4 – NSIC Rc192





V5 – Sapaw

Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

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Methods


Cultural Management Practices
Land Preparation. The aerobic field prepared under dry soil condition;
plowed twice, harrowed, leveled and furrowed. During the wet season, the
flooded plot puddled; flooded a day or two and then plowed, harrowed and
leveled.
Crop Establishment.The seeding rate was 320 viable seedsm2-1 or 1,920
seeds plot-1 (3 m x 2 m) for both aerobic and flooded plots. The seeds were hand-
dibbled 2 cm deep and covered with soil in aerobic fields. Each subplot had 6-
m2with eight 3-meter rows spaced at 25 cm apart.
In flooded plot, seeds weredirectly-seeded at a planting distance of 25 cm
between rows.
Water Management.The aerobic plots wereirrigated immediately after
sowing. Subsequent irrigations of about 5 cm depth were applied each time the
soil moisture potential at 15 cm depth reached 15cb. At flowering, the threshold
for irrigation was reduced to field capacity to avoid spikelet sterility (O’Toole and
Garrity, 1984). No ponded water was used except for part of the days of irrigation
and during heavy rainfall in the wet season (Boumanet al., 2005).

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The standing water was maintained in the flooded plots from seeding until
2 weeks before harvest. The initial water depth was be 2 cm and gradually
increased to 10 cm at full crop development.
The main plots were hydrologically separatedto prevent seepage of water
from the flooded plots into aerobic plots by establishing a set of double drains 40
cm deep between the main plots. Plastic sheets were at 40 cm depth in the bunds
of all main plots.
Nutrient Management.Based on the laboratory results,the fertilizer rates
used were as follows: 80-60-45 (wet season) and 90-60-45 (dry season) in
Lagangilang, Abra; 40-60-0 (wet season) and 50-60-0 (dry season) in Luna,
Apayao. Fertilizers were applied in three splits: 1) 30% N, all P & K 10-14 days
after emergence (DAE); 2) 35% N 20-35 DAE; and 3) 35% N 40-50 DAE. The
second and third N applicationvaried depending on the maturity of varieties used
in the experiment.
The nutrient management in Kapangan site followed the indigenous
practices in traditional rice production. There were no external inputs applied to
the area in order to sustain the organic production practices. The rice stubbles
were plowed under during land preparation to augment internal nutrient supply
for the organic rice production.
Pest Management.Observed the occurrence of the following insect pests
and diseases in Luna, Apayao: caseworm, leaffolders, stemborers, rat, and rice

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blast.The plants compensated from the early season damage caused by caseworm
and leaffolder by producing new leaves and tillers. Several preventive
management strategies were employed such as avoidance of excessive nitrogen
fertilizer application in Lagangilang, Abra and Luna, Apayao; and installation of
plastic nets and rat baits around the area in Luna, Apayao and Kapangan,
Benguet. No chemical pesticide was used in all three sites. Weeds were controlled
through manual weeding.
 
Data Gathered:
A. Agro-physiological Parameters
1. Plant Height at Maturity. This was measured (in cm) from 10 sample
plants randomly selected in each plot and taken from the average. At
physiological maturity, plant height was the length from the ground level to the
tip of the longest panicle, excluding the awns if any.
2. Days to Tillering, Booting, Heading and Ripening. These were recorded
by counting the number of days from seeding to maximum tillering, to booting, to
heading (emergence of the panicle out of the flag leaf sheath) and to ripening. It
was when 50% of the plants in each plot are at maximum tillering, booting,
heading stage and 80% physiologically mature.
3. Panicle Number. At physiological maturity, it was counted as the number
of panicles from 0.25 m2 area from each plot.

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4. Panicle Length. At maturity, panicle length was taken by measuring from
the panicle base to its tip excluding awns if any. Measurements were taken from
10 randomly selected plants per plot.
5. Total Grain Number per Panicle. At harvest, 10 panicles were randomly
collected from each plot, threshed and counted both the filled and unfilled.
6. Number of Filled Grains per Panicle. At harvest, 10 panicles were
randomly collected from each plot and threshed separately. Filled and unfilled
grains from each panicle were separated and counted.
7. Filled Grain Ratio (%). This was computed by using the formula:
Filled grain number
Filled grain ratio = ---------------------------- x 100
Total grain number

8. Weight of 1000-grain. This was taken by measuring the weight of 1000
filled grain adjusted to a 14% moisture basis.
9. Total Dry Matter (Aboveground Total Biomass). This was taken from 0.25
m2 sample area and computed as the total dry matter of straw and panicles.
10. Harvest Index. This was taken from 0.25 m2 area from each plot and
computed by using the formula:
Weight of dried filled grains
Harvest Index = ----------------------------------------------



Total weight of aboveground biomass

11. Grain Yield. The remaining area of each plot (5.75m2) was harvested for
grain yield adjusted to a 14% moisture basis.

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12. Computed Yield. This was derived by computing the grain yield per plot
(5.75m2) to a hectare.
13. Leaf Area Index. The leaf area of ten sample plants was taken from each
plot at 75 days after seeding (DAS) using the Tracing Technique method (Saupe,
2006). It was computed by using the formula:
-1
Leaf area (mm2) = weight of leaf tracing (g) x conversion factor (mm2 gm )
Total one-sided area of leaf tissue
Leaf area index = -----------------------------------------------



Ground surface area occupied by crop
B. Other Data
1. Reaction to Insect Pest and Diseases
a.
Caseworm. Recordedas the percent of damaged leaves in each plot
at 40 days after emergence from 20 randomly selected plants or hills/plot. The
damage was estimatedby recording the ratio of damaged over the total number of
leaves from randomly selected plants. The following rating scale was used
(INGER, 1996):
Scale Description
Rating
1
1-10% damaged plant
Resistant
3
11-20% damaged plant
Moderately Resistant
5
21-35% damaged plant
Intermediate
7
36-50% damaged plant
Moderately Susceptible
9
51-100% damaged plant
Susceptible

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b.
Leaffolder. Recordedas the percentage of damaged leaves during
the abundance of leaffolders from the twenty plants randomly selected in each
plot.It was computed as damaged over total number of leaves. The following
rating scale was used (INGER, 1996):
Scale Description
Rating
1
1-10% damaged plant
Resistant
3
11-20% damaged plant
Moderately Resistant
5
21-35% damaged plant
Intermediate
7
36-50% damaged plant
Moderately Susceptible
9
51-100% damaged plant
Susceptible
c.
Stem BorerDamage Evaluation (Whiteheads).Field rating was
based on actual infested panicles in a 0.25 m2 area at the center of each plot. Ten
sample plants were selected at random were counted ten days before harvest.
Percentage of whiteheads was recorded using the following standard rating scale
(INGER, 1996):
Scale Description
Rating
1
1-5% whiteheads
Resistant
3 6-10%
whiteheads
Moderately
Resistant
5 11-15%
whiteheads
Intermediate
7 16-25%
whiteheads
Moderately
Susceptible
9
26% and above
Susceptible

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d.
Rat Damage.Evaluation of rat damage was taken from the
damaged plants in a 0.25 m2 area of each plot. Ten sample plants were selected at
random were counted and observed based on the following rating scale (INGER,
1996):
Scale Description


Rating
1
Less than 5% damage observed
Resistant
5
6-25% damage observed

Intermediate
9
26-100% damage observed
Susceptible
e.
Rice Panicle Blast. Assessment of the severity of rice blast was
taken from the plants at the 0.25 m2 area of each plot. Ten sample plants were
taken randomly. Computation of percent infection was done using the formula
(INGER, 1996):
Number of panicle infected
%
Infection
=
---------------------------------------- x 100





Total number of panicles

Scale
Description
Rating

1
0-5% are affected
by
blast Resistant


3

6-25% are affected
by
blast Intermediate


5

26% &above are a
ffected by blast

Susceptible

2. Sensory evaluation. This adopted the procedure undertaken by Tad-awan,
et al (2010) with some modification. Samples of cooked rice were wrapped

---

22

individually with foil. Each person was given 10 samples of cooked rice varieties
and a bottled water. A sample score sheet was distributed to each person which
contains the following:
a. Aroma
1 -

bland
2 -
slightly
perceptible
3 -
moderate
4 -
strong
5 -
very
strong
aroma
b. Taste
1 -
no
taste
2 -
slightly
tasty
3 -
moderate
4 -
strongly
perceptible
5 -
very
strong
c. Texture
1 -
very
soft
2 -
moderately
soft
3 -
slightly
hard
4 -
moderately
hard
5 -
very
hard
texture

---

23

d. General Acceptability
1 -
dislike
extremely
2 -
dislike
very
much
3 -
dislike
moderately
4 -
dislike
slightly
5 -
neither like nor dislike
6 -
like
slightly
7 -
like
moderately
8 -
like very much
9 -
like
extremely
 
 
Analysis of Data
 
The data was analyzed through analysis of variance in RCBD.

Significance among treatment means was analyzed using the Duncan’s Multiple
Range Test (DRMT). Correlation analysis was also done.

---

24

The degree of relationship between two variables was measured using the
Pearson product moment correlation coefficient (R) which characterizes the
independence of X and Y (Amid, 2005). The coefficient R is a parameter which
can be estimated from sample data using the formula:


N ∑xy – (∑x)(∑y)



R =
[n ∑x2 – (∑x)2] [n(∑y) – (∑y)2]

---

RESULTS AND DISCUSSION
 
 
Study 1. Growth and Yield Performance of Rice Grown under Two
Moisture Regimes in Lagangilang, Abra during
Wet Season 2010 and Dry Season 2011


AgrometeorologicalConditions

Abra belongs to Type 1 climate which is characterized by two pronounced
seasons, dry from November to April and wet during the remaining months of the
year. The experimental site in Lagangilang, Abra has an elevation of 65 m asl. It
is classified under lowland zone (<100m asl) according to the Research,
Development and Extension Agenda and Program for the Cordillera Agro-
Forest/Fishery Ecological Zones classification (DA-CAR, 1999). It also falls
under the lowland irrigated ecosystem based on rice ecosystem classification
(Dobermann and Fairhurst, 2000).
The total rainfall for wet season 2010 and dry season 2011 were at 871.6
mm and 16.5 mm, respectively (Table 1). The minimum and maximum air
temperature during the study period ranged from 16.8oC to 23.4oC while the
maximum air temperature ranged from 35.5oC-37.7oC, respectively. The
temperature range is within the optimum range favorable for rice production of
18-40oC as cited by De Datta (1981). The relative humidity in both cropping
seasons ranged from 60.6 to 84.7% which is favorable for rice production.


Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes 
in Different Agro‐ecosystems /Virginia A. Tapat. 2012 

---

26 
 

Table 1. Meteorological data of Lagangilang, Abrafrom July 2010 to April 2011
CROPPING
RAINFALLa
RELATIVE
T
b
max
Tmin
Tavg
SEASON/
(mm)
HUMIDITY
(oC)
(oC)
(oC)
MONTH
%






Wet Season 2010c











July
257.0
79.9
37.7
23.2
28.6






August
226.1
82.6
37.0
23.4
28.0






September
207.9
84.7
36.8
23.0
27.8






October
180.7
81.4
37.2
20.1
28.1


November
-
77.06

20.3
-






Dry Season 2011











December 2010
-
69.4
36.0
18.5
26.6






January
-
64.4
36.3
17.1
26.2






February
12.0
62.4
37.0
16.8
27.1






March
4.5
60.6
37.3
19.0
27.9




April
-
58.2
35.5
18.9
29.0
aRainfall accumulated from July to November 2010 and December 2010 to April 2011.
bTmax, Tminand Tavgrefer to the means for the highest, lowest, and average temperature.
cTemperature and relative humidity data for WS 2010 were taken from PhilRice-Batac, Ilocos Norte


Soil Properties


The results of the analysis revealed that the soil was slightly acidic. A pH
of 6.27 favors the growth of rice plants. De Datta (1981) cited that the optimum
pH for rice growth and development ranges from 5.5 to 6.5. The bulk density of

---

27 
 
Table 2. Soil physical and chemical properties in Lagangilang, Abra




SOIL PROPERTY
VALUE


Chemical Properties
pH
6.27


OM (%)
1.50


P2O5 (ppm)
4.00


K20 (ppm)
36.0


Zn (ppm)
0.72


Physical Properties


Bulk Density (g/cc)
1.71


Water Holding Capacity (ml/g)
0.52


1.71 gcc-1 and water holding capacity of 0.52 ml g-1 indicates that the soil is
moderately compacted which inhibits root penetration in moist soil.

Groundwater and Standing Water Depths
Figure 1 shows the depths of groundwater and standing water for aerobic
plots in Lagangilang, Abra during the wet season (WS) 2010 and dry season (DS)
2011. The standing water levels were almost always below the soil surface
indicating unponding. The rainfall during the July-October 2010 wet season was
supplemented with irrigation water whenever measurements of standing water

---

28 
 
20.0 
‐
(20.0)
(40.0)
(60.0)
(80.0)
Centimeters
(100.0)
(120.0)
(140.0)
(160.0)
0
50
100
150
200
250
Number of Days
Groundwater
Standing water

Figure 1. Groundwater and standing water depths (cm) in aerobic fields,
Lagangilang, Abra (2010-2011)
 
depth in two (2) out of the three (3) standing water tubes were at 20 cm below the
soil surface. The standing water level indicates the available water supply for crop
growth and development. Likewise, when irrigation water is limited a shallow
ground water can be a hidden water supply for the rice crop for its growth and
development.
 
Soil Matric Potential
Figure 2 shows the soil matric potential in aerobic fields in Lagangilang,
Abra during the DS 2011. There was a series of increased moisture potential for a
few days indicating that there was no irrigation or rainfall. The reading was used

---

29 
 
35
30
25
a
r
s 20
t
i
b
n 15
Ce
10
5
0
1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64
Number of Days
 
Figure 2. Soil matric potential in Lagangilang, Abra during the DS 2011

to determine schedule of irrigation. When it reached 20-30 cb, the area was
irrigated so as not to subject the plants from water deficit stress. The
tensiometerreading therefore dropped to 0 cb every time irrigation water was
applied. The highest soil matric potential reached 31 cb.
 
Plant Height
Effect of moisture regime. Rice plants grown under flooded condition
were significantly taller than those grown under aerobic condition in both wet
season and dry season trials (Table 3). This corroborates the observation of De
Datta (1981) that plant height generally increases with increasing water depth
under flooded condition trials.

---

30 
 
Effect of variety. PSB Rc68 was the tallest but not significantly taller than
NSIC Rc192 and NSIC Rc9 in both season trials (Table 3). Said three varieties
were significantly taller than NSIC Rc136H and PSBRc14 in both trials.
During the WS 2010 trial, NSIC Rc136H was not significantly taller than
PSB Rc14 but was during the dry season 2011 trial.
From the results, it could be inferred that plant height is dependent on
variety. These results corroborate with Arraudeau and Vergara (1988) indicating
that upland rice varieties like NSIC Rc9, are tall ranging from 120 to 180 cm.
This characteristic may contribute to the high biomass and eventually yield.
Vergara (1992) also cited that reduced plant height is the most important
factor to increase the grain yield potential of rice. Shorter plants can take up
morenitrogen fertilizer without lodging, resulting in higher grain yields. Plants are
tall and leafy during the wet season since they shade each other and thisreduces
food production in the leaves. During the dry season, plants areshorter and have
fewer tillers since more light energy is available.
Interaction effect. There was no significant interaction observed between
the moisture regimes and the rice varieties in terms of plant height at
maturityduring the WS 2010 in Lagangilang, Abra. However, significant
interaction was noted during the DS 2011 (Figure 3). NSIC Rc9 and PSB Rc68
were the tallest at 80.09 cm and 97.61 cm under aerobic and flooded conditions,
respectively. This

---

31 
 

Table 3. Plant height of rice at physiological maturity in Lagangilang, Abra
during the WS 2010 and DS 2011

TREATMENT
PLANT HEIGHT (cm)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
115.15b 70.35b
Flooded
117.50a 84.67a
Varieties (V)


NSIC Rc 9
125.75a 88.15a
PSB Rc 14
95.38c 64.57b
PSB Rc 68
128.63a 87.22a
NSIC Rc 136H
106.75b 66.16b
NSIC Rc192
126.13a 81.44a
M x V
0.67ns 3.19*
CVa(%) 1.76
1.11
CVb(%) 4.76
4.20
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).


indicates that these two varieties may reach their inherent characteristic of being
tall-statured plants especially when there is ample supply of soil moisture.

---

32 
 
120.00 
100.00 
)
m
80.00 
 
(c
NSIC Rc9
i
g
ht
60.00 
PSB Rc14
t
 
he
PSB Rc68
a
n
40.00 
Pl
NSIC Rc136H
20.00 
NSIC Rc192
‐
Aerobic
Flooded
Soil Moisture Regimes


Figure 3. Interaction effect between the moisture regimes and the rice varieties on
plant height in Lagangilang, Abra during the DS 2011


Number of Days from Seeding to Maximum Tillering
Effect of moisture regime. Statistical analysis showed no significant
difference between the two moisture regimes in terms of number of days from
seeding to maximum tilleringduring the wet season2010 (Table 4) but it was
significantly different during the dry season 2011 (Table 5). Results showed that
under flooded condition, plants reached maximum tillering earlier than those
grown under aerobic condition in both cropping seasons.
Effect of variety. Significant differences were noted among the different
rice varieties in terms of number of days from seeding to maximum tillering
during the wet season and dry season trials. During the wet season, PSB Rc9
produced maximum tillers earliest at 32.25 days and was comparable with

---

33 
 


Table 4. Number of days from seeding to maximum tillering, maximum tillering
to booting, booting to heading, and heading to maturity of rice in
Lagangilang, Abra during the WS 2010

NUMBER OF DAYS FROM:
SEEDING
MAXIMUM
TREATMENT
BOOTING
HEADING
TO
TILLERING
TO
TO
MAXIMUM
TO
HEADING MATURITY
TILLERING
BOOTING
Moisture Regimes (M)

Aerobic
34.00
28.90
8.60
31.60
Flooded
33.85
28.65
8.70
31.80
Varieties (V)




NSIC Rc 9
32.25a
30.88c
10.63c
33.25c
PSB Rc 14
33.63ab
28.63b
7.75b
29.00b
PSB Rc 68
34.50b
28.88b
10.63b
42.00d
NSIC Rc 136H
33.88ab
28.38b
7.75b
28.25b
NSIC Rc192
35.38c
27.13a
6.50a
26.00a
M x V
1.24ns
2.71ns
0.14ns
2.23ns
CVa (%)
1.17
1.88
2.10
1.82
CVb (%)
2.5
3.80
6.10
2.27
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).

---

34 
 

Table 5. Number of days from seeding to maximum tillering, maximum tillering
to booting, booting to heading, and heading to maturity of rice in
Lagangilang, Abra during the DS 2011

NUMBER OF DAYS FROM:
SEEDING
MAXIMUM
TREATMENT
BOOTING
HEADING
TO
TILLERING
TO
TO
MAXIMUM
TO
HEADING MATURITY
TILLERING
BOOTING
Moisture Regimes (M)

Aerobic
42.25a
30.95
8.40
26.70
Flooded
39.20b
31.35
8.65
26.40
Varieties (V)




NSIC Rc 9
40.88a
33.25c
10.38c
38.00d
PSB Rc 14
41.75b
29.63b
7.63b
24.00b
PSB Rc 68
40.00a
35.50d
10.50c
19.38a
NSIC Rc 136H
40.88a
29.38b
7.75b
23.13b
NSIC Rc192
40.13a
28.00a
6.38a
28.25c
M x V
7.56**
2.01ns
0.27ns
8.22**
CVa (%)
1.33
1.44
7.01
5.71
CVb (%)
2.30
2.20
5.70
6.77
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).

PSB Rc14 and NSIC Rc136H at 33.63 days and 33.88 days, respectively. The
latest to reach maximum tillering was NSIC Rc192 at 35.38 days (Table 4).

---

35 
 
During the dry season study, PSB Rc68 reached the earliest maximum tillering
stage at 40.00 days but was not significantly earlier than NSIC Rc192, NSIC
Rc136H and NSIC Rc9. PSB Rc14 had the latest maximum tillering(Table 5).
The seeding to maximum tilleringstagseare part of the vegetative phase
which mainly determines the differences in growth duration of varieties. As cited
by Arraudeau and Vergara (1988), the duration of vegetative phase differs with
variety.
Interaction effect. There was no significant interaction observed between
the soil moisture regimes and the rice varieties on number of days from seeding to
maximum tillering stage during the wet season 2010 but had highly significant
interaction effect during the dry season 2011 (Figure 4).This result implies that
variety trials for aerobic rice production have to be conducted during the dry
season.
NSIC Rc136H had varied response during the DS 2011 under the two soil
moisture regimes. It was the latest to reach the maximum tillering stage from
seeding under aerobic at 44 days but the earliest under flooded condition at 37.75
days. Such trend goes to show that growth duration of NSIC Rc136H could be
shortened by ensuring available water supply in the field. PSB Rc68 reached
earliest the maximum tillering from seeding at 41.25 days under aerobic
condition.

---

36 
 

45.00 
44.00 
43.00 
42.00 
y
s
NSIC Rc9
41.00 
 
da
 
of 40.00 
PSB Rc14
er 39.00 
PSB Rc68
mb 38.00 
Nu 37.00 
NSIC Rc136H
36.00 
NSIC Rc192
35.00 
34.00 
Aerobic
Flooded
Soil Moisture Regimes

Figure 4. Interaction effect between the soil moisture regimes and the rice
varieties on number of days from seeding to maximum tillering in
Lagangilang, Abra during the DS 2011


Number of Days from Maximum Tillering to Booting
Effect of moisture regime. The two moisture regimes did not significantly
affect the number of days from seeding to tilleringboth during the wet season2010
and dry season 2011 (Table 4 and 5).
Effect of variety. Significant differences were noted among the different
rice varieties in terms of number of days from maximum tillering to booting
during the wet season and dry season (Tables 4 and 5). During the wet season,
NSIC Rc192 reached booting stage earliest at 27.13 days and NSIC Rc9 the latest

---

37 
 
at 30.88 days. During the dry season, NSIC Rc192 booted earliest at 28 days and
PSB Rc68 latest at 35.50 days.
From the results it could be inferred that the duration of maximum tillering
stage which is part of the vegetative phase differs with variety as confirmed by
Arraudeau and Vergara (1988).The determination of the panicle initiation stage,
which is prior to booting, is critical in nutrient management where nitrogen
fertilizer should be applied for panicle development.
Interaction effect. There was no significant interaction observed between
the soil moisture regimes and the rice varieties on number of days from
maximum tilleringto booting stage both during the wet season2010 and dry
season 2011 (Table 4 and 5).
 
Number of Days from Booting to Heading
Effect of moisture regime. The was no significant difference between the
two moisture regimes in terms of number of days from booting to heading stage in
Lagangilang, Abra both during the WS 2010and DS 2011 (Table 4 and 5).
Effect of variety. The number of days from booting to heading stage
significantly affected by the kind of variety during the wet season 2010 and dry
season2011 (Tables 4 and 5). During the wet season, NSIC Rc192 reached the
earliest heading stage while NSIC Rc9 and PSB Rc68reached the latest both.
During the dry season trial, NSIC Rc192 was the earliest to reach the heading
stagewhile PSB Rc68 reached the latest.Varieties differed also in the duration of

---

38 
 
the reproductive phase particularly from booting to heading stage.Variation in
growth stage duration among varieties could also mean employment of varied
intervention especially water application.
Interaction effect. There was no significant interaction observed between
the soil moisture regimes and the rice varieties on number of days from booting to
heading stage (Table 4 and 5).

Number of Days from Heading to Maturity
Effect of moisture regime. The two moisture regimes did not have
significant effect on the number of days from heading to maturityboth at the wet
season2010 and dry season2011 (Table 4 and 5).
Effect of variety. Significant differences were observed among the
different rice varieties in terms of number of days from heading to maturity. NSIC
Rc192 was the earliest to mature from heading during the wet season and PSB
Rc68 was the latest to mature (Table 4). However, during the dry season, PSB
Rc14 was the earliest to mature and NSIC Rc9 was the latest (Table 5).
The results indicate that maturity of varieties vary depending on the
cropping season. Nevertheless, maturity days of NSIC Rc9 and PSB Rc68 were
consistent with PhilRice’s Catalogue of PSB/NSIC Varieties (2009) as the latest
to mature among the varieties.
Interaction effect. There was no significant interaction observed between
moisture regimes and rice varieties on the number of days from heading to

---

39 
 
maturityduring the wet season trial (Table 4). Conversely, there was significant
interaction between the two during the dry season (Table 5). PSB Rc68 was the
earliest to mature from heading under aerobic and flooded conditions during the
dry season trial. In the same cropping season, NSIC Rc9 was the latest to mature
in both soil moisture regimes which is consistent with the PhilRice’s Catalogue of
PSB/NSIC Rice Varieties (2009).
 
 
45.00 
40.00 
35.00 
y
s
30.00 
NSIC Rc9
 
da
 
of 25.00 
PSB Rc14
er 20.00 
mb
PSB Rc68
15.00 
Nu 10.00 
NSIC Rc136H
5.00 
NSIC Rc192
‐
Aerobic
Flooded
Soil Moisture Regimes

Figure 5. Interaction effect between the moisture regimes and the varieties on the
number of days from heading to maturity in Lagangilang, Abra during
the DS 2011

Leaf Area Index at 75 DAS
Effect of moisture regime. No significant differences were observed
between the moisture regimes on leaf area index during the wet season 2010
(Table 6). During the dry season, however, a significant difference was noted.

---

40 
 
Plants grown under flooded fields had significantly higher leaf area index than
under aerobic condition (Bouman et al., 2005).The availability of sufficient water
supply in the soil in flooded plots combined with highersolar radiation during the
dry season may produce a significantly larger leaf area than those plants with
regulated soil moisture supply in aerobic fields. Further, Yabes, et al.,(2008) cited
that reduction of photosynthetically active leaf area should be prevented atpanicle
initiation to booting which is about 75 DAS as this will affect attainment of yield
potential.
The result also corroborated with the results of Bouman, et al (2005) that
there is a reduced leaf area in rice plants under aerobic than flooded condition.
Effect of variety. Leaf area index wassignificantly affected by the kind of
variety during both season trials (Table 6). NSIC Rc192 had the highest LAI
during the wet season which was comparable with PSB Rc68. During the dry
season, NSIC Rc192 maintained the highest leaf area index but which was not
significantly different with NSIC Rc9. PSB Rc14 had the lowest LAI for both
seasons. The difference in LAI among the varieties maybe due to their genetic
characteristic.
The importance of LAI was noted in rice. De Datta (1981) cited that the
total leaf area of a rice population is a factor closely related to grain production
because the total leaf area at flowering greatly affects the amount of
photosynthates available to the panicle.

---

41 
 
Table 6. Leaf area index at 75 DAS in Lagangilang, Abra during the WS 2010
and DS 2011

TREATMENT
LEAF AREA INDEX
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
2.57
2.44b
Flooded
2.54
4.40a
Varieties (V)


NSIC Rc9
2.89b 4.00a
PSB Rc14
1.83c 2.76b
PSB Rc68
2.95a 3.06ab
NSIC Rc136H
2.13bc 3.10ab
NSIC Rc192
2.96a 4.19a
M x V
0.22 ns
2.36ns
CVa(%) 6.02
5.85
CVa(%) 5.30
4.93
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).


Interaction effect. No significant interaction was observed between the
moisture regimes and the different rice varieties in terms of leaf area index in
Lagangilang, Abra during the WS 2010 and DS 2011.
 

---

42 
 
Panicle Number at Maturity
Effect of moisture regime. Table 7 shows the panicle number at maturity.
Significant differences were observed between the moisture regimes in terms of
panicle number at maturity in Lagangilang, Abraduring the wet and dry season
trials. Plants grown in flooded fields (92 and 103) produced more panicles than
the plants grown in aerobic plots (72 and 86) at both the wet and dry cropping
seasons, respectively.
The results agree with that of Penget al., (2006) that flooded rice produced
more panicles with more spikelets per panicle than aerobic rice. The results also
agree with that of Kato et al., (2006b) that there was a sharp reduction in panicle
number of some cultivars produced under suboptimal water condition like in
aerobic. However, the resultof this study contradictsthat of Abbasi and
Sepaskhah (2010) that the effect of water stressprolonged the growth duration of
rice cultivars in intermittent flood irrigation similar with aerobic rice that resulted
in higher number of panicles.
Effect of variety. No significant differences were observed among
varieties in terms of panicle number at maturity during the wet season trial (Table
7). During the dry season trial, however, significant differenceswere noted. NSIC
Rc192 produced the highest number of productive tillers during the wet season
trial while PSB Rc14 had the highest number of productive tiller during the dry
season trial. PSB Rc14 had the shortest but with the highest panicleper

---

43 
 
Table 7. Panicle number of rice plants at physiological maturity in Lagangilang,
Abra during the WS 2010 and DS 2011

PANICLE NUMBER AT PHYSIOLOGICAL
TREATMENT
MATURITY
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
72b 86b
Flooded
92a 103a
Varieties (V)


NSIC Rc 9
79
95b
PSB Rc 14
86
130a
PSB Rc 68
72
80b
NSIC Rc 136H
81
92b
NSIC Rc192
92
79b
M x V
1.38ns 0.30
ns
CVa(%) 3.58
2.37
CVa(%) 3.46
3.47
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).


unit area. On the other hand, PSB Rc68 had the longest yet with the least number
of panicles per unit area.

---

44 
 
Vergara (1992) foundthat rice varieties differ in tillering ability. The
number of tillers determines the number of panicles and is the most important
factor in achieving high grain yield.
Interaction effect. Statistical analysis showed no significant interaction
between the moisture regimes and the rice varieties on the panicle number at
maturity for both season trials (Table 7).

Panicle Length
Effect of moisture regime.Panicle length at physiological maturity was not
significantly affectedby moisture regimes during the wet season trial but was
significantlyaffected during the dry season trial (Table 8). Plants grown under
flooded condition produced longer panicles than plants in aerobic condition.
Longer panicles in flooded rice varieties had likewise more grain number than
under aerobic field.
Effect of variety. Highly significant differences were observed among
varieties in terms of panicle length (Table 8). PSB Rc68 produced the longest
panicleduring the wet season but was comparable with NSIC Rc136H and NSIC
Rc9. During the dry season, NSIC Rc9 had the longest panicle but not
significantly different with PSB Rc68, NSIC Rc192 and NSIC Rc136H.
PSB Rc68 had the longest panicle but it also had the least panicles per unit
area. In contrast, the PSB Rc14 which had the shortest panicles and the greatest
number of panicles per plot. The result implies that panicle length could be

---

45 
 
Table 8. Panicle length (cm) of rice plants at physiological maturity in
Lagangilang, Abra during the WS 2010 and DS 2011

PANICLE LENGTH ATPHYSIOLOGICAL
TREATMENT
MATURITY (cm)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
24.67
19.67b
Flooded
24.82
21.77a
Variety (V)


NSIC Rc 9
25.24ab 22.05a
PSB Rc14
23.00c 18.60b
PSB Rc68
26.48a 21.40a
NSIC Rc 136H
25.26ab 20.73a
NSIC Rc192
23.74bc 20.82a
M x V
2.40ns 1.89ns
CVa (%)
4.50
6.00
CVb (%)
3.08
3.49
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).


influenced by the genetic make-up of the varieties.
Interaction effect. Statistical analysis showed no significant interaction
between the moisture regimes and the rice varieties on the length of panicle at
harvest during both season trials(Table 8).

---

46 
 
 
Total Grain Number per Panicle
Effect of moisture regime. While no significant differences were noted on
the number of grains per panicle during the wet season trial, the number of grains
per panicle markedly differ during the dry season (Table 9). Plants grown under
aerobic plots produced more grains per panicle during the wet season. On the
contrary, the number of grains per panicle is significantly higher under flooded
than aerobic fields.
The results agreed with the results of Katoet al., (2006b) and Penget al.,
(2006) that flooded rice produced more panicles with more grains (spikelets) than
aerobic rice.Kato et al., (2006a) deduced that reduced panicle production might be
due to shallower roots of aerobic rice that resulted in reduced nitrogen uptake and
decreased dry matter production.
Effect of variety. Significant differences were found among the rice
varieties in terms of the number of grains per panicle (Table 9). NSIC Rc9
produced the highest number of grains per panicle during both season trials. This
variety also had the longest panicle during the dry season trial but was
comparable with PSB Rc68 which had the longest panicle during the wet season
trial. This variety also had highest number of grains per panicle. Conversely, PSB
Rc14 consistently produced the least number of grains per panicle since it had the
shortest panicle at both cropping seasons.

---

47 
 
Table 9. Grain number of panicle in Lagangilang, Abra during the WS 2010 and
DS 2011

TREATMENT
GRAIN NUMBER PER PANICLE
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
149.00
78.00b
Flooded
142.00
107.00a
Varieties (V)


NSIC Rc 9
182.00a 115.00a
PSB Rc 14
101.00d 66.00b
PSB Rc 68
168.00a 101.00a
NSIC Rc 136H
128.00c 79.00b
NSIC Rc192
148.00b 100.00a
M x V
1.75ns 1.47ns
CVa (%)
9.11
0.00
CVb (%)
8.35
3.65
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).


The foregoingresults imply that yield parameters such as panicle length
and total number of grains per panicle could be some characteristics inherent to
the variety. Moreover, the yield of varieties with the most number of grains
(NSIC Rc9 and PSB Rc68) may still be further improved by avoidance of water

---

48 
 
stress during flowering and by employing appropriate cultural management
practices like proper timing of fertilizer application at panicle initiation and
flowering stages.
Interaction effect. Statistical analysis revealed no significant interaction
between the moisture regimes and the different rice varieties in relation to grain
number per panicle during the wet and dry season trials(Table 9).

Number of Filled Grains per Panicle
Effect of moisture regime.The number of filled grains per panicle did not
significantlydiffer between the two moisture regimes during the wet season trial
but significantly differed during the dry season trial. Plants grown under flooded
plots had produced a higher number of filled grains per panicle during the dry
season.
Effect of variety. Significant differences were found among the rice
varieties in terms of the number of filled grains per panicle (Table 10). NSIC Rc 9
had the highest number of filled grains per panicle for both season trials. This
variety consistently had the longest panicle with the most total and filled grains
per panicle.In contrast, PSB Rc14 had the lowest number of filled grains per
panicle in both cropping seasons. It had likewise the shortest and least total grain
number per panicle.
Proper timing of fertilizer application at panicle initiation and flowering
stages may increase the number of filled grain per panicle in varieties with large

---

49 
 
Table 10. Number of filled grains per panicle in Lagangilang, Abra during the WS
2010 and DS 2011

TREATMENT
NUMBER OF FILLED GRAINS PER PANICLE
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
115
60b
Flooded
115
82a
Variety (V)


NSIC Rc 9
150a 91a
PSB Rc 14
78d 52c
PSB Rc 68
117b 79b
NSIC Rc 136H
100c 56c
NSIC Rc192
130b 78b
M x V
1.66ns 1.62ns
CVa (%)
9.18
4.92
CVb (%)
8.42
3.09
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).


panicle size. Likewise, the occurrence of water stress during the flowering stage
can reduce filled grains per panicle (Abbasi and Sepaskhah, 2010) and therefore
should be avoided.

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50 
 
Interaction effect. There was no significant interaction noted between the
moisture regimes and the different rice varieties in relation to grain number per
panicle during both season trials (Table 10).

Filled Grain Ratio
Effect of moisture regime. Results showed that during the wet season trial,
the different rice varieties grown under flooded fields had a higher filled grain
ratio as compared tothose grown under aerobic plots. However, during the dry
season trial, higher filled grain ratio was observed to the plants that were grown
under aerobic plots as compared to the plants grown under flooded fields.
PhilRice (2001) reported that large amount of unfilled grains is due to lack
of water.
Effect of variety. There were significant differences noted among the rice
varieties in terms of filled grain ratio (Table 11). During the wet season trial,
NSIC Rc192 had the highest filled grain ratio at 88.00and PSB Rc68 had the
lowest with a mean of 70.00. During the DS, NSIC Rc9 had a highest filled grain
ratio at 78.80 which was comparable with PSB Rc14with a mean of 78.06. NSIC
Rc 136H had the lowest filled grain ratio of 72.11.
Both NSIC Rc9 and NSIC Rc192 performed wellin terms of filled grain
ratio regardless of soil moisture condition. This implies that these varieties are
adapted to irrigated, upland and lowland rainfed ecosystems. Furthermore, highly
significant differences could be due to the compactness of grains in the panicle.

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51 
 
Table 11. Filled grain ratio of rice plants in LagangilangAbra during the WS 2010
and DS 2011

TREATMENT
FILLED GRAIN RATIO (%)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
77.50
77.27
Flooded
80.65
76.34
Variety (V)


NSIC Rc 9
83.13b 78.80a
PSB Rc 14
76.63c 78.06a
PSB Rc 68
70.00d 77.21b
NSIC Rc 136H
77.63c 72.11b
NSIC Rc192
88.00a 77.87b
M x V
1.49 ns
3.04*
CVa (%)
4.36
6.44
CVb (%)
4.66
5.27
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
Interaction effect. There were no significant interactions noted between
the moisture regimes and the rice varieties in terms of filled grain ratio during the
wet season trial but significant interaction was observedduring the dry season trial
(Figure 6). NSIC Rc9 under aerobic condition produced the highest filled grain

---

52 
 
ratio during the dry season trial and PSB Rc68 had the highest in flooded
condition. The result impliesthe suitability of a particular variety to a specific soil
moisture condition in Lagangilang, Abra as far as filled grain ratio is concerned.
 
 
84.00 
82.00 
80.00 
) 78.00 
 
(%
76.00 
NSIC Rc9
t
i
o
 
ra 74.00 
PSB Rc14
a
i
n 72.00 
 
gr
PSB Rc68
d 70.00 
68.00 
NSIC Rc136H
F
ille
66.00 
NSIC Rc192
64.00 
62.00 
Aerobic
Flooded
Soil Moisture Regimes

Figure 6. Interaction between the moisture regimes and the rice varieties on filled
grain ratio in Lagangilang, Abra during the DS 2011.


Weight of 1000 Filled Grains
Effect of moisture regime. Statistical analysis revealed no significant
differences between the two moisture regimes on the weight of 1000 grains at
both season trials (Table 12). Plants grown under aerobic condition had higher
weight of 1000 grains during the wet season but lower during the dry season trial.

Table 12. Weight of 1000 filled grains in Lagangilang, Abra during WS 2010 and
DS 2011

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53 
 

TREATMENT
WEIGHT OF 1000 FILLED GRAINS (g)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
26.85
22.88
Flooded
26.62
24.30
Variety (V)


NSIC Rc 9
23.89c 21.59c
PSB Rc 14
24.65c 21.49c
PSB Rc 68
30.34a 27.45a
NSIC Rc 136H
27.51b 25.16b
NSIC Rc192
27.28b 22.26c
M x V
1.21 ns
1.58ns
CVa (%)
1.30
6.07
CVb (%)
3.89
3.25
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
Effect of variety. Highly significant differences among the varieties in
terms of weight of 1000 grains were noted (Table 12). PSB Rc68 had the heaviest
weight of 1000 grains in both season trials. The lowest weight was recorded from
NSIC Rc9 during the wet season trial and PSB Rc14 during the dry season. These
results supports the PhilRice’s PSB/NSIC Rice Catalogue (2009) that among the

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54 
 
five varieties, PSB Rc68 has the largest grain size. As other yield parameters may
be enhanced with improved cultural management practices, the weight of 1000-
graincould begenetically influenced and maybe considered as an important
parameter in the selection of a variety with high yield potential.
Interaction effect. No significant interaction was observed between the
moisture regimes and the rice varieties on the weight of 1000 grains (Table 12).
This contradicts the result of the study of Abbasi and Sepaskhah (2011) that there
was a significant interaction effect between cultivars and irrigation regimes on
1000 grain weight.
 
Total Dry Matter Weight
Effect of moisture regime. Results show that there was no significant
differences observed between the moisture regimes in terms of total dry matter
weight during the wet season trial but it had highly significant difference during
the dry season trial (Table 13). In both seasons, plants grown under flooded plots
had a higher dry matter weight.
The dry season trial results agree with the results of Katoet al., (2006a)
that some cultivars under adequate water supply produced the largest total dry
matter and the least under low water supply. Further he cited that in general, total
dry matter increased with increasing water supply. Likewise, Lafitte and Benett
(2002) suggested that the reason for lower total dry mater weight under aerobic
 

---

55 
 
Table 13. Total dry matter weight of rice plants in Lagangilang, Abra during the
WS 2010 and DS 2011

TREATMENT
TOTAL DRY MATTER WEIGHT (g)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
266.75
129.03b
Flooded
267.10
200.38a
Variety (V)


NSIC Rc9
301.19b 182.63a
PSB Rc14
231.44c 164.31ab
PSB Rc68
382.88a 185.25a
NSIC Rc136H
213.00c 154.63bc
NSIC Rc192
206.13c 136.69c
M x V
0.41 ns
2.09ns
CVa (%)
0.13
1.88
CVb (%)
2.83
4.01
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
condition may be related to the relatively shallow root system and stomata closure
and reduced photosynthesis in response to surface soil drying.

---

56 
 
Effect of variety There were highly significant differences noted among
the rice varieties in terms of total dry matter weight in both cropping seasons
(Table 13). PSB Rc68 had the heaviest total dry matter weight in both season
trials.PSB Rc68 was also the tallest in wet season trialbut not significantly
different with NSIC Rc9, the tallest during the dry season trial. From the
foregoing results, it could be inferred that tall varieties have high total dry matter
weight. Furthermore, PSB Rc68 also had the heaviest 1000-grain weight under
both moisture regimes and in both growing periods.
Interaction effect. There was no significant interaction observed between
the moisture regimes and the varieties in terms of total dry matter weight (Table
13).The results contradict with the results of Kato et al., (2006a) that cultivar-
water regime interaction in total dry matter weight is significant. Results revealed
that different cultivars responded differently to the water conditions and that the
local water supply greatly affected total dry matter in upland conditions through
its effects on the amount of N uptake, which was associated with the depth of root
development. 
 
Harvest Index
Effect of moisture regime. Statistical analysis revealed that there was no
significant difference observed between the two moisture regimes on harvest
index during the wet season trial but highly significant difference was observed
during the dry season trial (Table 14). The significantly higher harvest index in

---

57 
 
Table 14. Harvest index of rice plants in Lagangilang,Abra during the WS 2010
and DS 2011

TREATMENT
HARVEST INDEX
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
0.51
0.41b
Flooded
0.52
0.50a
Varieties (V)


NSIC Rc9
0.51b 0.39c
PSB Rc14
0.55a 0.49b
PSB Rc68
0.43c 0.32d
NSIC Rc136H
0.55a 0.53a
NSIC Rc192
0.52ab 0.54a
M x V
0.34 ns
0.77ns
CVa (%)
6.38
3.99
CVb (%)
7.25
5.95
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
flooded condition than in aerobic during the dry season may be attributed to a
higher assimilation rate of rice plants in plots with sufficient moisture supply in
the soil.

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58 
 
Effect of variety. There were highly significant differences noted among
the varieties in terms of harvest index (Table 14). Results show that during the
wet season trial, NSIC Rc136H and PSB Rc14 had the highest harvest index but
comparable with NSIC Rc192.In the same season, PSB Rc 68 had the lowest
harvest index.
During the dry season trial, NSIC Rc192 had the highest harvest index but
not significantly different with NSIC Rc136H. PSB Rc68 had maintained as the
lowest with a mean harvest index.
In both cropping season trials, both NSIC Rc136H and NSIC Rc192
attained the highest grain yield and harvest index which could be inferred that
these varieties had higher assimilation rate as manifested by their high economic
(grain) over the biological (biomass) yield. The higher the harvest index, the
higher the economic yield. A high harvest index maybe a manifestation of the
superiority of these varieties over the others.
On the other hand, PSB Rc68 had the lowest harvest index for both season
trials but was also the tallest during the wet season trial. This supports De Data
(1981) that tall plants have reduced harvest index.
Interaction effect. Statistical analysis revealed no significant interaction
between the moisture regimes and the rice varieties in terms of harvest index
(Table 14).
 
 
 
 

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59 
 
Grain Yield
Effect of moisture regime. Significant differences were observed between
the two moisture regimes on the weight of grain yield in both the season trials
(Table 15).
Results show that plants grown under aerobic condition were 0.25 g (7%)
and 1.59 g (46%) lower than those under flooded fields during the wet season and
dry season trials, respectively. The significant differences between the two
moisture regimes could be attributed by the amount of water used by plants. Lack
of water at any growth stage may reduce grain yield. In general, the difference in
yield between aerobic and flooded rice was greater in dry season than in wet
season trial. The yield difference was associated with variability in the soil water
status of aerobic rice between dry and wet season trial (Boumanet al.,2005).
Further, low temperature of 16.8-17.10C was experienced in January-
February 2011 in Lagangilang, Abra which might have affected the reproductive
phase of the rice plants eventually producing a lower grain yield during dry
season than the wet season trial.
Effect of variety. Statistical analysis shows significant differences among
the varieties on grain yield. Results show that NSIC Rc136H had the highest grain
yield but comparable with NSIC Rc192 during both season trials. On the other
hand, the lowest grain yield was obtained from PSB Rc14 during the wet season
trial and PSB Rc68 during the dry season trial.

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60 
 
Table 15. Grain yield (g) in Lagangilang,Abra during the WS 2010 and DS 2011
TREATMENT
GRAIN YIELD (kg/5.75 m2)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
3.45b
1.86b
Flooded
3.69a 3.45a
Variety (V)


NSIC Rc 9
3.53b 2.44bc
PSB Rc 14
3.10b 2.90a
PSB Rc 68
3.17b 2.19c
NSIC Rc 136H
4.11a 2.96a
NSIC Rc192
3.95ab 2.76ab
M x V
0.74ns
0.41ns
CVa (%)
0.89
7.86
CVb (%)
2.13
12.50
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).


The highest mean grain yield under aerobic condition was NSIC Rc192 at
3.10 kg 5.75 m2-1 and the lowest from PSB Rc68 with 2.16 kg 5.75 m2-1. The
highest grain yield of NSIC Rc192 was attributed by its high mean filled grain
ratio (82%) and high harvest index (0.51). Its early maturity is likewise a positive
trait.

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61 
 
Under flooded condition, NSIC Rc136H outyielded the other varieties.
NSIC Rc136H had the highest yield under this soil moisture regime due to its
high harvest index of 0.56.

The results confirm the high yielding ability of NSIC Rc192 under water
deficit condition and of NSIC R136H, a hybrid variety, under a favorable
condition as far as soil moisture is concerned (PhilRice, 2009).
Interaction effect. There were no significant interactions between the
moisture regimes and the different rice varieties in terms of grain yield for both
cropping seasons.

Computed Yield per Hectare
Effect of moisture regime. Significant differences were observed between
the two moisture regimes on the weight of grain yield (Table 16).
Results show that plants grown under flooded fields had a higher
computed yield as compared to the plants grown under aerobic plots. There was a
yield reduction of 0.42 tha-1 (7%) and 2.77 tonsha-1 (46%) in aerobic plots over
flooded fields during the wet season and dry season trials, respectively. There was
a smaller yield difference between the two moisture regimes during the wet
season because of the readily available water supply from rainfall in aerobic plots
as compared to the dry season. During the wet season, the water usage between

---

62 
 

Table 16. Computed yield (t ha-1) in Lagangilang, Abra during the WS 2010 and
DS 2011
TREATMENT
COMPUTED YIELD (t ha-1)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
6.00b 3.23b
Flooded
6.42a 6.00a
Variety (V)


NSIC Rc9
6.15a 4.25b
PSB Rc14
5.40b 5.05a
PSB Rc68
5.49b 3.81b
NSIC Rc136H
7.14a 5.16a
NSIC Rc192
6.86a 4.81a
M x V
0.76ns 0.41ns
CVa (%)
2.88
12.50
CVb (%)
8.58
8.36
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
aerobic and flooded was almost similar. On the other hand, yield gap was larger
during the dry season since aerobic condition was almost strictly imposed in
aerobic plots with minimal rainfall only in February and March 2011. Soil

---

63 
 
moisture was generally supplied by irrigation water.
Effect of variety. Statistical analysis showed significant differences among
the varieties in terms of grain yield during the wet season and dry season trials
(Table 18). NSIC Rc136H outyielded the other varieties in both seasons with a
mean of computed yield of 7.14 tons ha-1 and 5.16 tons ha-1, respectively.Lowest
computed yield was obtained from PSB Rc14 (5.40 tonsha-1) during the wet
seasontrial and PSB Rc68 (3.81 tons ha-1) during the dry season trial.
The results show that the highest mean computed yield across seasons was
from NSIC Rc192 (5.39 t ha-1) and NSIC Rc136H (7.11 t ha-1) under aerobic and
flooded conditions, respectively. High filled grain ratio and harvest index
contributed to such high computed yield of these varieties. This confirms the
adaptability of NSIC Rc192 under aerobic condition and NSIC Rc136H under
flooded condition in Lagangilang, Abra.
Interaction effect. There was no significant interaction between the
moisture regimes and the different rice varieties on computed yield (Table 16).
 
Water Use Efficiency
Effect of moisture regime. Table 17shows the water use efficiency with
respect to total water input (irrigation + rainfall). Significant differences between
the moisture regimes on water use efficiency were noted both during the wet and
cropping seasons. Under aerobic condition, water use efficiency was 0.64g grains
l-1 and 0.82g grains l-1 in WS 2010 and DS 2011, respectively. This is 0.04g

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64 
 

Table 17. Water use efficiency (g grains/liter) of rice in Lagangilang, Abra during
WS 2010 and DS 2011

TREATMENT
WATER USE EFFICIENCY (g grains l-1)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
0.64b
0.82b
Flooded
0.68a 1.44a
Variety (V)


NSIC Rc 9
0.66ab 1.04bc
PSB Rc 14
0.58b 1.24a
PSB Rc 68
0.59b 0.93c
NSIC Rc 136H
0.76a 1.26a
NSIC Rc192
0.74a 1.18ab
M x V
0.72 ns
0.34ns
CVa (%)
0.00
0.08
CVb (%)
2.40
12.80
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
grains l-1 (6%) and 0.62 g grains l-1 (43%)lower than the flooded plots for same
study period. Further, the water use efficiency in flooded plots (1.44 g grains l-1)
is 75% higher than in aerobic plots during the dry season trial. This may be due to
a much higher (85%) grain yield in flooded than in aerobic condition.

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65 
 
The results contradict with the results of Belderet al., (2005)in 2002 and
2003 that water use efficiency under flooded condition in 2002 and 2003 was 36
and 41% lower than in aerobic plots, respectively.
Under a water scarce condition in rice production, the ability of a rice
variety to produce a high yield or maintain its yield level under a favorable soil
moisture condition such as flooded (water use efficiency) is now a much sought
after character. It is now becoming a key consideration in the selection of variety
for upland and lowland rainfed rice ecosystems. As a water saving technology,
aerobic rice has been claimed by rice experts of having a high water use
efficiency.
Effect of variety. Significant differences among the varieties in terms of
water use efficiency were noted (Table 17). During the wet season trial, NSIC
Rc136H had the highest water useefficiency at 0.76g grains l-1 but not
significantly different with NSIC Rc192 at 0.74 g grains l-1and comparable with
PSB Rc9 at 0.66g grains l-1. The lowest water use efficiency was registered from
PSB Rc14 at 0.58 g grains l-1.
Further, during the dry season, NSIC Rc136H had maintained the highest
water use efficiency but not significantly different with PSB Rc14 and
comparable with NSIC Rc192. The lowest water use efficiency was obtained from
PSB Rc68 with a mean of 0.93g grains l-1.

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66 
 
The results imply that NSIC Rc192 and NSIC Rc136H are adapted under
aerobic condition in Lagangilang, Abrain terms of water use efficiency.
Interaction effect. Statistical analysis revealed that there was no significant
interaction between the moisture regimes and different rice varieties on water use
efficiency. The results show that although there was a reduction in yield in
aerobic than in flooded condition, such scenario is compensated by a relatively
lower reduction in water use efficiency.

Reaction to Insect Pests and Diseases
In Lagangilang, Abra, all varieties in both moisture regimes were found to
be resistant to defoliators, stemborer (deadhearts and whiteheads), blast and rat
damages. This could be attributed to the favorable weather conditions during the
growing periods.
 
Sensory Evaluation
Aroma. PSB Rc68 in both soil moisture regimes had bland aroma while
the rest had moderate aroma (Table 18).
Taste. PSB Rc68 and NSIC Rc136H had slightly tasty grains while the
grains of other varieties had varied tastes with respect to soil moisture regimes.
Texture. All four varieties, except PSB Rc68, in both soil moisture
regimes, had moderately soft grains. PSB Rc68 in aerobic fields had moderately
soft but had slightly hard grains in flooded plots.

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67 
 

Table 18. Sensory evaluation of rice varieties in Lagangilang, Abraduring the WS
2010 and DS 2011

SOIL
GENERAL
MOISTURE
VARIETY AROMA TASTE
TEXTURE
ACCEPTABILITY
REGIMES
NSIC Rc9
Moderate
Slightly
Moderately
Like moderately
tasty
Soft
PSB Rc14
Moderate
Slightly
Moderately
Like slightly
tasty
Soft
AEROBIC
PSB Rc68
Bland
No taste
Moderately
Like slightly
Soft
NSIC Rc136H
Moderate
Slightly
Moderately
Like moderately
tasty
Soft
NSIC Rc192
Moderate
Slightly
Moderately
Like very much
tasty
Soft
NSIC Rc9
Moderate
Moderate
Moderately
Like slightly
Soft
PSB Rc14
Moderate
Slightly
Moderately
Like slightly
tasty
Soft
PSB Rc68
Bland
Slightly
Like slightly
FLOODED
Slightly hard
tasty
Moderately
NSIC Rc136H
Moderate
Slightly
Like slightly
Soft
tasty

NSIC Rc192
Moderate
Moderate
Moderately
Like slightly
Soft
 

General Acceptability. NSIC Rc192 in aerobic plots was liked very much
by the evaluators. This variety grown under aerobic condition had both moderate
aroma and moderately soft texture.

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68 
 
Study 2: Growth and Yield Performance of Rice Grown under Two Moisture
Regimes in Luna, Apayao during the Wet Season 2010
and Dry Season 2011


Agrometeorological Conditions
 
The climate in Apayao has a Type III classification characterized by not
very pronounced dry and wet season, relatively from the months of December to
April and wet during the rest of the year. Heaviest rain occurs during the months of
August or September.
Luna, Apayao has an elevation of 5 m asl. It is classified under lowland
zone (<100m asl) according to the Research, Development and Extension Agenda
and Program for the Cordillera Agro-Forest/Fishery Ecological Zones classification
(DA-CAR, 1999). It also falls under the lowland rainfed ecosystem based on rice
ecosystem classification (Dobermann and Fairhurst, 2000).

The total rainfall for wet season 2010 and dry season 2011 were at 1,310.1
mm and 2,070.5 mm, respectively (Table 19). The minimum air temperature during
the study period ranged from 16.9oC to 22.6oC while the maximum air temperature
ranged from 27.4oC to34.2oC. The temperature range is within the optimum range
favorable for rice production as cited by De Datta (1981) of 18-40oC. The relative
humidity in both cropping seasons ranged from 75.0% to 88.2% which is favorable
for rice production. These environmental conditions namely rainfall, temperature
and relative humidity greatly affect the growth and development of rice crops.
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
Different Agro‐ecosystems /Virginia A. Tapat. 2012 

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69 
 
Table 19. Meteorological data of Luna, Apayao from July 2010 to April 2011
CROPPING
RAINFALLa
RELATIVE
T
b
max
Tmin
Tavg
SEASON/
(mm)
HUMIDITY
(oC)
(oC)
(oC)
MONTH
%






Wet Season 2010c











July
73.1
75.0
34.2
22.6
28.4






August
273.3
75.0
34.0
22.3
28.2






September
72.2
77.0
33.3
21.9
27.6






October
187.1
77.0
32.8
21.9
27.4

November
704.4
82.0
29.5
21.1
25.3






Dry Season 2011











December 2010
411.6
86.5
28.0
20.8
24.1






January
515.2
88.2
27.4
18.9
23.0






February
81.3
83.2
28.8
16.9
23.8






March
518.3
84.0
30.7
19.8
24.2



April
103.7
80.5
31.7
20.3
25.8
aRainfall accumulated from July to November 2010 and December 2010 to April 2011.
b Tmax, Tmin and Tavg refer to the means for the highest, lowest, and average temperature.
c Temperature and relative humidity data for WS 2010 were taken from PAGASA Tuguegarao City

Soil Properties

The results of the analysis revealed that the soil was moderately acidic at pH
of 5.7. De Datta (1981) cited that the optimum pH for rice growth and development
ranges from 5.5 to 6.5. The fertilizer applied was based on this fertility level and in
consideration with the required nutrient requirement of a rice crop.
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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Table 20. Soil physical and chemical properties in Luna, Apayao



SOIL PROPERTY
VALUE


Chemical Properties
pH
5.70


OM (%)
4.00


P2O5 (ppm)
5.00


K20 (ppm)
140.0


Zn (ppm)
2.41


Physical Properties


Bulk Density (g cc-1)
1.72


Water Holding Capacity (ml g-1)
1.10




The bulk density of 1.72 g cc-1 and water holding capacity of 0.52 ml g-1
indicates that the soil is moderately compacted which inhibits root penetration in
moist soil.

Groundwater and Standing Water Depths
Figure 7 shows the depths of groundwater and standing water for aerobic
plots in Luna, Apayao in wet season and dry season trials. The water levels were
almost always below the soil surface indicating unponding. The standing water
depths during the wet season were more erratic than during the dry season which
indicated that there were more rainfall and frequent rainy days during the latter
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71 
 
season (December 2010-March 2011). The ground water levelsin November 2010
and March 2011 were shallow since recorded rainfall during these months were
high.Water supply in aerobic fields was supplemented with irrigation water
whenever measurements of standing water depth in two (2) out of the three (3)
standing water tubes were at 20 cm below the soil surface. A relatively higher
irrigation input was applied during the July-November 2010 cropping season than
during the December 2010-March 2011 with a recorded rainfall of 1,310.10 mm
and 1,526.40 mm, respectively.

20.0 
‐
(20.0)
(40.0)
(60.0)
Centimeters
(80.0)
(100.0)
(120.0)
0
50
100
150
200
250
Number of Days
Groundwater Depth
Standing water Depth

Figure 7. Groundwater and standing water depths (cm) in aerobic fields, Luna,
Apayao (2010-2011)

 
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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Soil Matric Potential
The soil matric potential in Luna, Apayao during the early growth stage of
the rice plant in dry cropping seasonwas almost close to zero signifying that the soil
is wet (Figure 8). De Data (1981) cited that when the matric potential is close to
zero, the soil is said to be water-saturated and at its maximum retentive capacity.
The fluctuation in tensiometer readingwas attributed by the amount of
rainfall and application of irrigation water during the cropping season.


18
16
14
12
a
r
s
10
t
i
b
n
8
Ce
6
4
2
0
1 3 5 7 9 1113151719212325272931333537394143454749515355
Number of Days
 
 
Figure 8. Soil matric potential in Luna, Apayao during the DS 2011







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Plant Height
Effect of moisture regime. Rice plants grown under flooded condition were
significantly taller than those grown under aerobic condition in wet season but not
in dry season trial (Table 21). This corroborates the observation of De Datta (1981)
that plant height generally increases with increasing water depth under flooded
condition trials.
Effect of variety. NSIC Rc9 was the tallest but not significantly taller than
NSIC Rc192 and PSB Rc68 in both season trials (Table 23). PSB Rc14 was the
shortest variety also in both cropping seasons. Varieties differ in plant height due to
their inherent or genetic characters.
These results confirmed by Arraudeau and Vergara (1988) that upland rice
varieties, like NSIC Rc9, are tall ranging from 120 to 180 cm. This characteristic
enables the upland varieties produce high biomass and yield.
Interaction effect. The interaction of soil moisture regimes and varieties had
significantly affected the height of the rice plants in Luna, Apayao during the wet
season trial but none during the dry season trial (Figure 8). NSIC Rc 9 and NSIC
Rc192 were recorded as the tallest both under aerobic and flooded conditions. This
result shows consistency of these varieties in terms of plant height under both soil
moisture regimes. On the other hand, the result contradicts the study of Abbasi and
Sepaskhah (2011) indicating that cultivars and irrigation regimes had no interaction
effect.
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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Table 21. Plant height of rice at maturity in Luna, Apayao during the WS 2010
and DS 2011

TREATMENT
PLANT HEIGHT (cm)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
106.25b 94.92
Flooded
122.20a 99.84
Variety (V)


NSIC Rc 9
128.25a 114.12a
PSB Rc 14
89.88c 74.06d
PSB Rc 68
122.75a 113.58a
NSIC Rc 136H
102.75b 83.59c
NSIC Rc192
127.50a 101.28b
M x V
3.0*
0.73ns
CVa (%)
3.69
7.25
CVb (%)
4.11
3.91
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).



Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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75 
 
160.00 
140.00 
120.00 
)
m
NSIC Rc9
 
(c 100.00 
i
g
ht
80.00 
PSB Rc14
t
 
he
PSB Rc68
60.00 
a
n
Pl
NSIC Rc136H
40.00 
NSIC Rc192
20.00 
‐
Aerobic
Flooded
Soil Moisture Regimes

Figure 9. Interaction effect between the moisture regimes and the varieties on
plant height in Luna, Apayao during the WS 2010
 

Number of Days from Seeding to Maximum Tillering

Effect of moisture regime. Statistical analysis showed a significant
difference between the two moisture regimes in terms of number of days from
seeding to tillering during the wet season trialbut not significantly different during
the dry season trial (Table 22). Results showed that under flooded condition, plants
reached maximum tillering earlier than those grown under aerobic condition in both
cropping seasons.
Effect of variety. Significant differences were noted among the different
rice varieties in terms of number of days from seeding to maximum tillering during
the wet and dry season trials. During the wet season trial, PSB Rc14 produced
maximum tillers earliest at 33.63 days which was not significantly earlier
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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Table 22. Number of days from seeding to maximum tillering, maximum tillering
to booting, booting to heading, and heading to maturity of rice in Luna,
Apayao during the WS 2010

NUMBER OF DAYS FROM:
SEEDING
MAXIMUM
TREATMENT
BOOTING
HEADING
TO
TILLERING
TO
TO
MAXIMUM
TO
HEADING MATURITY
TILLERING
BOOTING
Moisture Regimes (M)

Aerobic
37.15b
32.75a
6.90
22.10a
Flooded
35.10a
29.50b
7.35
25.05b
Varieties (V)




NSIC Rc 9
35.15a
31.88b
8.63b
23.13ab
PSB Rc 14
33.63a
31.50b
6.25a
21.88a
PSB Rc 68
42.13b
34.50c
8.63b
25.38c
NSIC Rc 136H
34.38a
30.50b
6.13a
23.63b
NSIC Rc192
35.38a
27.25a
6.00a
23.88bc
M x V
4.05*
14.19**
1.12ns
3.44*
CVa (%)
0.44
5.07
6.65
6.04
CVb (%)
4.00
3.70
7.70
4.93
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).




Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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Table 23. Number of days from seeding to maximum tillering, maximum tillering
to booting, booting to heading, and heading to maturity of rice in Luna,
Apayao during the DS 2011

NUMBER OF DAYS FROM:
SEEDING
MAXIMUM
TREATMENT
BOOTING
HEADING
TO
TILLERING
TO
TO
MAXIMUM
TO
HEADING MATURITY
TILLERING
BOOTING
Moisture Regimes (M)

Aerobic
42.25
35.95
10.30
32.25
Flooded
41.85
35.00
10.35
32.25
Varieties (V)




NSIC Rc 9
38.00b
34.25a
11.75c
37.50c
PSB Rc 14
43.75c
33.63a
9.63b
28.63a
PSB Rc 68
50.38d
42.13b
12.13c
31.63b
NSIC Rc 136H
42.75c
34.38a
9.75b
31.25ab
NSIC Rc192
35.38a
33.00a
8.38a
32.25b
M x V
2.0ns
3.32* 0.43ns
3.77*
CVa (%)
4.87
4.50
6.31
9.30
CVb (%)
4.50
5.30
4.40
6.15
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).

than NSIC Rc136H, NSIC Rc9 and NSIC Rc192. PSB Rc68 had the latest tillering
(Table 22). During the dry season trial, NSIC Rc192 had reached earliest the
maximum tillering stage and PSB Rc68 again had the latest maximum tillering.
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The seeding to maximum tillering stage is part of the vegetative phase
which mainly determines the differences in growth duration of varieties. As cited
by Arraudeau and Vergara (1988), the duration of vegetative phase differs with
variety.
Interaction effect. There was a significant interaction observed between the
soil moisture regimes and the rice varieties on number of days from seeding to
maximum tillering stage during the wet season trial (Figure 10) but none during the
dry season trial.
 
 
50.00 
45.00 
40.00 
y
s 35.00 
NSIC Rc9
 
da 30.00 
 
of
PSB Rc14
25.00 
er
20.00 
PSB Rc68
mb
Nu 15.00 
NSIC Rc136H
10.00 
NSIC Rc192
5.00 
‐
Aerobic
Flooded
Soil Moisture Regimes

Figure 10. Interaction effect between the soil moisture regimes and the rice
varieties on number of days from seeding to maximum tillering in
Luna, Apayao during the WS 2010
 

Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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PSB Rc14 reached earliest the maximum tillering stage under aerobic
condition and NSIC Rc9 under flooded condition. The results implied that the
vegetative growth phase of the rice varieties differed depending on the soil moisture
regime in Luna, Apayao.
 
Number of Days from Maximum Tillering to Booting
Effect of moisture regime. There was a significant difference between the
two moisture regimes in terms of number of days from maximum tillering to
booting during the wet season trial but not significantly different during the dry
season trial (Table 23). Results show that under flooded condition, plants booted
earlier than those grown under aerobic condition in both cropping seasons.
Effect of variety. Significant differences were noted among the different
rice varieties in terms of number of days from maximum tillering to booting
(Tables 23). During the wet season trial, NSIC Rc192 reached earliest the booting
stage and PSB Rc68 the latest. For dry season trial, NSIC Rc192 had the earliest
booting stage but not significantly different with PSB Rc14, NSIC Rc9 and NSIC
Rc136H. PSB Rc68 was the latest to reach the booting stage.
From the results, it could be inferred that the duration of maximum tillering
which is part of the vegetative phase differ with variety as confirmed by Arraudeau
and Vergara (1988). The determination of the panicle initiation stage, which is prior
to booting, is critical in nutrient management where nitrogen fertilizer application
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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should be undertaken as it is one of the growth stages where rice needs nitrogen for
panicle development.
Interaction effect. There was a significant interaction observed between the
soil moisture regimes and the rice varieties on number of days from maximum
tillering to booting stage both during the wet season trial(Figure 11) and dry season
trial (Figure 12).
 
40.00 
35.00 
30.00 
y
s
NSIC Rc9
 
da 25.00 
 
of
PSB Rc14
20.00 
er
PSB Rc68
mb 15.00 
Nu 10.00 
NSIC Rc136H
5.00 
NSIC Rc192
‐
Aerobic
Flooded
Soil Moisture Regimes

Figure 11. Interaction effect between the soil moisture regimes and the rice
varieties on number of days from maximum tillering to booting in
Luna, Apayao during the WS 2010
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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50.00 
45.00 
40.00 
y
s 35.00 
NSIC Rc9
 
da 30.00 
 
of
PSB Rc14
25.00 
er
20.00 
PSB Rc68
mb
Nu 15.00 
NSIC Rc136H
10.00 
NSIC Rc192
5.00 
‐
Aerobic
Flooded
Soil Moisture Regimes


Figure 12. Interaction effect between the soil moisture regimes and the rice
varieties on number of days from maximum tillering to booting in
Luna, Apayao during the DS 2011

 
 
During the wet season trial, NSIC Rc136H reached earliest the booting
stage in aerobic plots and NSIC Rc192 in flooded fields (Figure 11). During the dry
season, NSIC Rc192 was the earliest under aerobic and NSIC Rc9the earliest under
flooded condition (Figure 12).
The results show that the varieties differed also in the duration of the
reproductive phase specially from booting to heading. Variation in growth stage
duration among varieties could also mean employment of varied intervention such
as water management.
 
 
 
 
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Number of Days from Booting to Heading
Effect of moisture regime. There was no significant difference between the
two moisture regimes in terms of number of days from booting to heading (Table
23). Plants under aerobic condition reached the earlier heading stage than those
grown under flooded condition in both cropping seasons.
Effect of variety. The number of days from booting to heading stagewas
significantly affected by the kind of variety (Tables 24 and 25). During the wet
season trial, NSIC Rc192 reached the earliest heading stage but not significantly
earlier than NSIC Rc136H and PSB Rc14.NSIC Rc9 and PSB Rc68 both reached
the latest.During the dry season trial, NSIC Rc192 was the earliest to reach the
heading stage while PSB Rc68 reached the latest.
Interaction effect. There was no significant interaction observed between the
soil moisture regimes and the rice varieties on number of days from booting to
heading stage (Table 23).

Number of Days from Heading to Maturity
Effect of moisture regime. The two moisture regimes had significant effect
on the number of days from heading to maturity during the wet season trial but
none during the dry season trial (Table 22& 23). Plants under aerobic plots matured
earlier than under in the flooded fields during the wet season. Varieties during the
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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dry season trial had similar duration from heading to maturity stage in both soil
moisture regimes.
Effect of variety. Significant differences were noted among the different
rice varieties in terms of number of days from heading to maturity (Table 22 and
23). PSB Rc14 was the earliest to mature in both season trials. This variety was
comparable with NSIC Rc9 during the wet season study. PSB Rc68 was the latest
to mature during the same season. For dry season trial, PSB Rc14 was comparable
with NSIC Rc136H. The latest to reach the maturity from heading stage was NSIC
Rc9.
From the results, it could be inferred that maturityof varieties differs
depending on the cropping season. Nevertheless, maturity days of NSIC Rc9 and
PSB Rc68 were consistent with PhilRice’s Catalogue of PSB/NSIC Varieties
(2009) as the latest to mature among the varieties.
Interaction effect. There was a significant interaction observed between the
moisture regimes and the rice varieties on the number of days from heading to
maturity(Figure 13 and 14).
During the wet season trial, NSIC Rc192 was earliest to mature in aerobic
plots and PSB Rc14 earliest in flooded fields (Figure 13). During the dry season
study, PSB Rc14 was earliest to mature under both soil moisture regimes (Figure
14). These results indicate the consistency of PSB Rc14 on the duration of heading
to maturity stages regardless of moisture regime.
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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30.00 
25.00 
y
s
20.00 
NSIC Rc9
 
da
 
of
PSB Rc14
15.00 
er
mb
PSB Rc68
10.00 
Nu
NSIC Rc136H
5.00 
NSIC Rc192
‐
Aerobic
Flooded
Soil Moisture Regimes


Figure 13. Interaction effect between the moisture regimes and the rice varieties on
number of days from heading to maturity in Luna, Apayao during the
WS 2010

45.00 
40.00 
35.00 
y
s 30.00 
NSIC Rc9
 
da
25.00 
 
of
PSB Rc14
er 20.00 
PSB Rc68
mb 15.00 
Nu
NSIC Rc136H
10.00 
NSIC Rc192
5.00 
‐
Aerobic
Flooded
Soil Moisture Regimes

Figure 14. Interaction effect between the moisture regimes and the rice varieties on
the number of days from heading to maturity in Luna, Apayao during
the DS 2011
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Leaf Area Index (LAI) at 75 Days After Seeding (DAS)
Effect of moisture regime. No significant differences were noted between
the two moisture regimes on leaf area index for both wet and dry season trials
(Table 24). Plants grown under flooded field had higher leaf area index than plants
under the aerobic plots.
Effect of variety. Leaf area index was significantly affected by the kind of
variety during both season trials (Table 24). During the wet season trial, NSIC
Rc192 had the highest LAI while PSB Rc68 had the lowest. During the dry season,
NSIC Rc9 had the highest LAI but comparable with NSIC Rc192. PSB Rc14 had
the lowest LAI during the same season.
The importance of LAI was likewise noted in rice. De data (1981) reported
that the total leaf area of a rice population is a factor closely related to grain
production because the total leaf area at flowering greatly affects the amount of
photosynthates available to the panicle. Close correlation between grain yield and
leaf area index at heading.
Interaction effect. No significant interaction was observed between the
moisture regimes and the different rice varieties in terms of leaf area index (Table
24).


Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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Table 24. Leaf area index at 75 days after seeding (DAS) in Luna, Apayao during
the WS 2010 and DS 2011

TREATMENT
LEAF AREA INDEX
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
3.24
9.95
Flooded
4.78
11.27
Varieties (V)


NSIC Rc9
4.3 4b 12.75a
PSB Rc14
3.45bc 8.15c
PSB Rc68
2.68c 9.98abc
NSIC Rc136H
3.75bc 9.69bc
NSIC Rc192
5.84a 12.48ab
M x V
0.68ns 0.11ns
CVa (%)
9.07
5.42
CVb (%)
5.16
10.68
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).

Panicle Number at Maturity
Effect of moisture regime.There was no significant difference observed
between the moisture regimes in terms of panicle number at maturity for both wet
and dry season trials (Table 25). During the wet season trial, plants grown in
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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Table 25.Panicle number at physiological maturity in Luna, Apayao during the WS
2010 and DS 2011

PANICLE NUMBER AT PHYSIOLOGICAL
TREATMENT
MATURITY
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
115
99
Flooded
118
97
Variety (V)


NSIC Rc 9
153a 82b
PSB Rc 14
80d 130a
PSB Rc 68
107c 87b
NSIC Rc 136H
113c 95b
NSIC Rc192
130b 88b
M x V
1.5ns 0.92ns
CVa (%)
8.50
3.94
CVb (%)
10.10
3.50
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).


flooded field produced more panicles than under aerobic plots. In contrast, plants
grown under aerobic plots produced more panicles than under flooded fields during
the dry season trial.
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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The results agree with that of Peng, et a.,l (2006) that flooded rice produced
more panicles with more spikelets per panicle than aerobic rice. The result also
agree with that of Kato et al., (2006b) that there was a sharp reduction in panicle
number of some cultivars produced under suboptimal water condition like in
aerobic. However, the result of this study contradicts that of Abbasi and Sepaskhah
(2010) that the effect of water stress prolonged the growth duration of rice cultivars
in intermittent flood irrigation similar with aerobic rice that resulted in higher
number of panicles.
Effect of variety. The different varieties significantly differed on panicle
number at maturity both during the wet and dry season trials (Table 25). NSIC Rc9
produced the highest number of panicles during the wet season trial but it had
produced the lowest number of panicles during the dry season. Conversely, PSB
Rc14 had the lowest number of panicles during the wet season trial but it had the
highest number during the dry season trial.
Vergara (1992) cited that rice varieties differ in tillering ability. The number
of tillers determines the number of panicles and it is the most important factor in
achieving high grain yield.
Interaction effect. Statistical analysis showed no significant interaction
between the moisture regimes and the rice varieties on the panicle number at
maturity for both season trials (Table 25).


Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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89 
 
Panicle Length
Effect of soil moisture regime. Panicle length at physiological maturity was
significantly affected by moisture regimes during the wet season trial but not during
the dry season trial (Table 26). In both seasons, results showed that plants grown
under flooded condition produced longer panicles than plants in aerobic condition.
Longer panicles in flooded fields had more grain number per panicle.
Effect of variety. Highly significant differences were observed among
varieties in terms of panicle length (Table 26). During the wet season trial, NSIC
Rc9 had the longest panicle but not significantly different with NSIC Rc136H and
PSB Rc68. During the dry season trial, PSB Rc68 had significantly the longest
panicle while PSB Rc14 had the shortest panicle in both seasons.
The results imply that across seasons PSB Rc68 and PSB Rc14 consistently
produced the longest and shortest panicles, respectively. This may be due to their
inherent characters.
Interaction effect. Statistical analysis showed no significant interaction
between the moisture regimes and the rice varieties on the length of panicle at
physiological maturity (Table 26).
 
Total Grain Number Per Panicle
Effect of moisture regime. There was no significant difference between the
two moisture regimes on number of grains per panicle during the wet season trial

Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes in 
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Table 26.Panicle length (cm) of rice in Luna, Apayao during the WS 2010 and DS
2011

TREATMENT
PANICLE LENGTH (cm)
WS 2010
DS 2011
Moisture Regimes (M)
Flooded
23.37a
21.50
Variety (V)


NSIC Rc 9
24.40a 21.57b
PSB Rc 14
20.93b 19.93d
PSB Rc 68
23.75a 23.06a
NSIC Rc 136H
24.23a 20.97c
NSIC Rc192
21.55b 20.03d
M x V
1.17ns 2.08ns
CVa (%)
2.93
0.81
CVb (%)
3.88
2.66
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
but a significant difference was noted during the dry season trial (Table 27). Plants
grown. Plants grown under flooded fields produced more grains per panicle for
both season trials.
The results agree with Katoet al., (2006b) and Penget al., (2006) that
flooded rice produced more panicles with more grains (spikelets) than aerobic
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rice.Katoet al., (2006a) deduced that reduced panicle production might be due to
shallower roots of aerobic rice that resulted in reduced nitrogen uptake and
decreased dry matter production.
Effect of variety. Highly significant differences were found among the
varieties in terms of the number of grains per panicle for both cropping seasons
(Table 27). NSIC Rc9 had the highest grain number per panicle during the wet
season trial and PSB Rc68 during the dry season trial. The latter (PSB Rc68) was
not significantly different with PSB Rc9 on grains per panicle during the dry season
trial. PSB Rc14 had the shortest panicles with the lowest number of grains per
panicle in both seasons.
The foregoing results indicate that varieties with the longest panicle in a
cropping season had likewise the most grains in a panicle; NSIC Rc9 for wet season
trial and PSB Rc68for dry season trial.
The foregoing results imply that yield parameters such as panicle length and
total number of grains per panicle could be some characteristics inherent to the
variety. Moreover, the yield of varieties with the most number of grains (NSIC Rc9
and PSB Rc68) may still be further improved by avoidance of water stress during
flowering and by employing appropriate cultural management practices like proper
timing of fertilizer application at panicle initiation and flowering stages.


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Table 27.Total grain number per panicle in Luna, Apayao during the WS 2010 and
DS 2011

TREATMENT
TOTAL GRAIN NUMBER PER PANICLE
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
115.00a 126.00b
Flooded
118.00a 143.00a
Variety (V)


NSIC Rc 9
153.00a 151.00a
PSB Rc 14
79.00d 98.00b
PSB Rc 68
107.00c 153.00a
NSIC Rc 136H
113.00c 149.00a
NSIC Rc192
130.00b 120.00b
M x V
1.44ns 2.00ns
CVa (%)
8.42
11.82
CVb (%)
10.15
13.16
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
Interaction effect. Statistical analysis revealed no significant interaction
between the moisture regimes and the different rice varieties in relation to grain
number per panicle in both season trials (Table 27).

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Number of Filled Grains per Panicle
Effect of moisture regime.The number of filled grains per panicle did not
significantly differ between the moisture regimes during the wet season trial but
significantly differed during the dry season trial (Table 28). Plants grown under
flooded fields produced higher number of filled grains per panicle for both seasons.
Vergara (1992) cited that lack of water at flowering can cause low
percentage of filled spikelets or grains.
Effect of variety. Highly significant differences were found among the
varieties on number of filled grains per panicle (Table 28).NSIC Rc9 had the
highest while PSB Rc14 had the lowest number of filled grains per panicle in both
season trials.
NSIC Rc9 had the longest panicle with the most grains per panicle and the
highest number of filled grains per panicle across seasons. In contrast, PSB Rc14
had the shortest panicle with the lowest number of filled grains per panicle in both
season trials.
Proper timing of fertilizer application at panicle initiation and flowering
stages could increase the number of filled grain per panicle in varieties with large
panicle size. Likewise, the occurrence of water stress during the flowering stage can
reduce filled grains per panicle (Abbasi and Sepaskhah, 2010).


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Table 28.Number of filled grains per panicle in Luna, Apayao during the WS 2010
and DS 2011

TREATMENT
NUMBER OF FILLED GRAINS PER PANICLE
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
76
89b
Flooded
83
102a
Variety (V)


NSIC Rc 9
106a 124a
PSB Rc 14
57b 68c
PSB Rc 68
63b 115a
NSIC Rc 136H
71b 92b
NSIC Rc192
101a 76c
M x V
0.97ns 1.77ns
CVa (%)
2.29
8.96
CVb (%)
2.86
8.52
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
Interaction effect. There was no significant interaction noted between the
moisture regimes and the different rice varieties in relation to grain number per
panicle in both season trials (Table 28).

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Filled Grain Ratio
Effect of moisture regime.Filled grain ratio was significantly affected by the
two moisture regimes during the wet season trialbut was not significantly affected
during the dry season trial (Table 29). Results show that during the wet season, the
different rice varieties grown under flooded fields had a higher filled grain ratio as
compared to the plants grown under aerobic plots.
PhilRice (2001) reported that large amount of unfilled grains is due to lack
of water.
Effect of variety. Highly significant differences were observed among
varieties on filled grain ratio for both wet and dry season trials (Table 29). Results
show that NSIC Rc192 had the highest filled grain ratio during the wet season
cropping and NSIC Rc9 during the dry season trial.This trend is similar with the
filled grain ratio during the wet and dry season in Lagangilang, Abra. From the
results, it could be inferred that these varieties are adapted both in Luna, Apayao
and Lagangilang, Abra based on filled grain ratio.
Interaction effect. There was a significant interaction observed between the
moisture regimes and the rice varieties during the wet season trial but there was
none during the dry season trial (Figure 15). NSIC Rc192 had the highest filled
grain ratio both under aerobic and flooded conditions during the wet season trial.
The result implies that NSIC Rc192 could perform well in terms of filled grain ratio
regardless of soil moisture status during the wet season cropping in Luna, Apayao.
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Table 29.Filled grain ratio in Luna, Apayao during the WS 2010 and DS 2011

TREATMENT
FILLED GRAIN RATIO (%)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
65.70a 69.31
Flooded
70.30b 71.19
Variety (V)


NSIC Rc 9
69.25b 81.90a
PSB Rc 14
71.75ab 69.82b
PSB Rc 68
59.13c 75.59ab
NSIC Rc 136H
62.38c 62.44c
NSIC Rc192
77.50a 61.53c
M x V
3.76*
0.94ns
CVa (%)
4.84
8.86
CVb (%)
6.40
9.84
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).

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90.00 
80.00 
) 70.00 
 
(% 60.00 
NSIC Rc9
t
i
o
50.00 
 
ra
PSB Rc14
a
i
n 40.00 
 
gr
PSB Rc68
d 30.00 
NSIC Rc136H
F
ille 20.00 
NSIC Rc192
10.00 
‐
Aerobic
Flooded
Soil Moisture Regimes


Figure 15. Interaction between the moisture regimes and the rice varieties
onfilled grain ratio in Luna, Apayao during the WS2010
 
 
 
Weight of 1000 Filled Grains
Effect of moisture regime. Statistical analysis revealed no significant
differences between the moisture regimes on the weight of 1000 grains in both
season trials (Table 30). Plants had heavier 1000 filled grains under flooded
condition during the wet season trialand under aerobic condition during the dry
season.
Effect of variety. Highly significant differences among the rice varieties in
terms of weight of 1000 grains were noted in both wet and dry season trials (Table
30). PSB Rc68 had the heaviest 1000-grain weight and PSB Rc14 had the lightest
across cropping seasons. These results in Luna, Apayao are similar with the data in
Lagangilang, Abra on weight of 1000 filled grains.
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Table 30. Weight of 1000 filled grains (g) in Luna, Apayao during the WS 2010
and DS 2011

TREATMENT
WEIGHT OF 1000 FILLED GRAINS (g)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
25.96
25.15
Flooded
26.17
24.70
Variety (V)


NSIC Rc 9
24.93c 22.80c
PSB Rc 14
24.13d 22.54c
PSB Rc 68
30.53a 29.93a
NSIC Rc 136H
26.19b 25.78b
NSIC Rc192
24.56cd 23.58c
M x V
1.24ns 0.51ns
CVa (%)
1.24
8.47
CVb (%)
2.57
7.40
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).

Likewise, these results support PhilRice’s PSB/NSIC Rice Catalogue (2009)
that among the five varieties, PSB Rc68 has the largest grain size. As other yield
parameters can be enhanced with improved cultural management practices, the
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weight 0f 1000-grain is could be genetically influenced and maybe considered as an
important parameter in the selection of a variety with high yield potential.
Interaction effect. No significant interaction was observed between the
moisture regimes and the rice varieties on the weight of 1000 grains both during the
wet and dry season trials (Table 30). This contradicts the result of the study of
Abbasi and Sepaskhah (2011) that there was a significant interaction effect between
cultivars and irrigation regimes on 1000 grain weight.
 
Total Dry Matter Weight
Effect of moisture regime. Dry matter weight was significantly affected by
the two moisture regimes during the wet season trial but was not significantly
affected during the dry season trial (Table 31). Statistical analysis showed that
plants grown under flooded fields had higher dry matter weight as compared to the
plants grown under aerobic plots during wet season trial.
The wet season result agrees with Kato et al., (2006a) that some cultivars
under adequate water supply produced the largest total dry matter and the least
under low water supply. He further cited that in general, total dry matter increased
with increasing water supply. Likewise, Lafitte and Benett (2002) suggested that
the reason for lower total dry mater weight under aerobic condition may be related
to the relatively shallow root system and stomata closure and reduced
photosynthesis in response to surface soil drying.

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Table 31. Total dry matter weight of rice in Luna, Apayao during the WS 2010 and
DS 2011

TREATMENT
TOTAL DRY MATTER WEIGHT(g)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
268.38b 272.30
Flooded
329.28a 275.84
Varieties (V)


NSIC Rc 9
338.32a 282.44ab
PSB Rc 14
249.38c 224.38b
PSB Rc 68
312.13ab 339.50a
NSIC Rc 136H
288.63bc 255.44b
NSIC Rc192
305.69ab 261.19b
M x V
0.05ns 0.33ns
CVa (%)
6.07
0.00
CVb (%)
12.90
2.19
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
Further, Peng et al., (2006) cited that yield difference between aerobic and
flooded rice was attributed more to difference in biomass production than to harvest
index.
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Effect of variety. There were highly significant differences noted among the
rice varieties in terms of total dry matter weightduring both season trials (Table 31).
NSIC Rc9 had the highest weight of total dry matter during the wet season trial but
comparable with PSB Rc68 and NSIC Rc192. During the dry season trial, PSB
Rc68 had the highest total dry matter but comparable with NSIC Rc9. Lowest
weight of total dry matter was obtained from PSB Rc14 for both WS and DS with a
mean of 249.38 g and 224.31 g, respectively.

NSIC Rc9 and PSB Rc68 were the tallest in Luna, Apayao in both growing
seasons and had likewise the highest total dry matter weight. It could be inferred
that tall varieties have high dry matter weight.
Interaction effect. There was no significant interaction observed between the
moisture regimes and the rice varieties on total dry matter weight during wet and
dry season trials (Table 31).


Harvest index
Effect of moisture regime. No significant difference was observed between
the two moisture regimes in terms of harvest index during the wet season trial but
was significantly different during the dry season trial (Table 32). Results show that
plants grown under flooded condition had higher harvest index in both cropping
seasons.
Effect of variety. There were highly significant differences noted among the
rice varieties in terms of harvest index (Table 32). Results show that during the wet
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Table 32. Harvest index of rice in Luna, Apayao during the WS 2010 and DS 2011

TREATMENT
HARVEST INDEX
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
0.35
0.41b
Flooded
0.38
0.46a
Varieties (V)


NSIC Rc 9
0.37b 0.43b
PSB Rc 14
0.41a 0.38c
PSB Rc 68
0.24c 0.42bc
NSIC Rc 136H
0.41a 0.53a
NSIC Rc192
0.42a 0.43b
M x V
1.34ns 1.69ns
CVa (%)
10.21
5.36
CVa (%)
7.32
8.72
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
season trial, NSIC Rc192 had the highest index but not significantly different with
NSIC Rc136 and PSB Rc14. PSB Rc68 had the lowest harvest index during the
same cropping season. NSIC Rc136H had the highest harvest index and PSB Rc14
had lowest during the dry season trial. From the results, it could be inferred that
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NSIC Rc136H exhibited its superiority over the other varieties across seasons based
on its high harvest index.
Interaction effect. Statistical analysis revealed no significant interaction
between the moisture regimes and the rice varieties in terms of harvest indexduring
both season trials (Table 32).
 
Grain Yield
Effect of moisture regime. Significant differences were observed between
the two moisture regimes on the weight of grain yield during the wet and dry
season trials. Results show that plants grown under aerobic fields had 9-31% (0.24-
0.89 kg) lower grain yield than the plants grown under flooded plots.
Yield variation is associated with the difference in the soil water status
between aerobic and flooded fields as cited by Bouman et al (2005). Further, they
reported that the difference in yield between aerobic and flooded rice is greater in
dry season than in wet season trial.
Effect of variety. Statistical analysis show significant differences among the
varieties in terms of grain yield both during the wet season and dry season trials
(Table 33).During the wet season, NSIC Rc9 produced the highest yield with a
mean of 3.02 kg and it had the lowest yield reduction in aerobic plots as compared
to flooded fields of 22% (0.75 kg) (Table 33). PSB Rc68 produced the lowest grain
yield of 1.24 kg and 1.99 kg under aerobic and flooded plots, respectively. Its grain
yield under aerobic was 38% (0.75 kg) lower than the flooded fields.
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Table 33. Grain yield (kg) in Luna, Apayao during the WS 2010 and DS 2011

TREATMENT
GRAIN YIELD PER (kg5.75 m2-1)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
2.03b 2.45
Flooded
2.92a 2.71
Variety (V)


NSIC Rc 9
3.02a 3.11b
PSB Rc 14
2.23b 1.39c
PSB Rc 68
1.62c 3.80a
NSIC Rc 136H
2.67ab 3.06b
NSIC Rc192
2.85ab 1.62c
M x V
0.58ns 0.94ns
CVa (%)
4.44
6.38
CVb (%)
9.27
12.96
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
During the dry season trial, PSB Rc68 attained the highest mean grain yield
of 3.77 kg; under aerobic and flooded conditions of 3.54 kg and 4.01 kg,
respectively (Table 37). However, its grain yield in aerobic plot was 12% (0.47 kg)
lower than in flooded plots. A 5% (0.16 kg) increased in grain yield under aerobic
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105 
 
conditiononly in PSB Rc9 plants. The rest of the varieties had yield reduction in
aerobic plots from 5-29% as compared to flooded fields.
Based on mean grain yield for two cropping seasons under aerobic
condition, NSIC Rc9outyielded the other varieties brought about by its long
panicle, high grain number per panicle, high filled grain ratio, and high total dry
matter weight. In flooded fields, NSIC Rc136H had the highest mean grain yield as
brought about by a high harvest index.
The results confirm the high yielding ability of NSIC Rc9 under water
deficit condition and of NSIC R136H, a hybrid variety, under a favorable condition
as far as soil moisture is concerned (PhilRice, 2009).
Interaction effect. There were no significant interaction between the
moisture regimes and the different rice varieties in terms of grain yieldduring the
wet and dry season trials (Table 33).
 
Computed Yield
Effect of moisture regime. Highly significant differences were noted
betweenthe moisture regimes in terms of computed yield per hectare of the different
rice varieties during the wet and dry season trials (Table 34). Results show that
plants grown under flooded fields had higher yield as compared to the plants grown
under aerobic plots. There was a yield reduction of 1.55 t (33%) in aerobic plots
compared to flooded fields during the wet season trial and 0.43 t (9%) during the
dry season trial.
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Table 34. Computed yield of rice production in Luna Apayao during the WS 2010
and DS 2011

TREATMENT
COMPUTED YIELD (t ha-1)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
3.54b 4.29b
Flooded
5.09a 4.72a
Varieties (V)


NSIC Rc 9
5.24a 5.41b
PSB Rc 14
3.89ab 2.41c
PSB Rc 68
2.83b 6.56a
NSIC Rc 136H
4.65a 5.32b
NSIC Rc192
4.95a 2.82c
M x V
0.59ns 0.83ns
CVa (%)
10.03
0.00
CVb (%)
9.86
4.26
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
In general terms, computed yields in Luna, Apayao were lower than in
Lagangilang, Abra since the latter had a more favorable weather condition during
the wet season and dry season trials. Higher recorded rainfall and more frequent
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rainy days in Luna, Apayao caused the caseworm and cutworm infestation and
panicle blast infection.
Effect of variety. There were significant differences observed among the
different rice varieties on computed yieldduring the wet season and dry season trials
(Table 34). Highest grain yield was obtained from NSICRc 9 during the wet season
with a mean of 5.24 tonha-1 while the lowest grain yield (2.83 tonsha-1) was from
PSB Rc68. During the dry season trial, PSB Rc68 had the highest computed yield
with a mean of 6.56 tons ha-1.
Interaction effect. There was no significant interaction between the moisture
regimes and the different rice varieties on computed yield (Table 34).
 
Water Use Efficiency
Effect of moisture regime. Table 35 shows the water use efficiency (WUE)
with respect to total water input (irrigation + rainfall). Statistical analysis revealed
highly significant differences in Luna, Apayao both during the wet season and dry
season trials. WUE in aerobic field was 0.06 g grains l-1 (43%)higher than in the
flooded fields during the dry season despite the former’s lower grain yield.
The results in Luna, Apayao for wet season contradict with Belder et al.,
(2005) that water use efficiency under flooded condition in 2002 and 2003 was 36
and 41% lower than in aerobic plots, respectively. The dry season trial result,
however, supports the findings of Belderet al., (2005) and Bouman et al., (2005)
that water use efficiencyfor rice under aerobic condition ranges from 32-88%.
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Effect of variety. Statistical analysis showed highly significant differences
among the rice varieties in terms of WUE during both seasons (Table 35). NSIC
Rc9 had the highest WUE during the wet season trialbut not significantly different
with NSIC Rc192 and NSIC Rc136H and comparable with PSB Rc14.

Table 35. Water use efficiency of rice in Luna, Apayao during the WS 2010 and DS
2011

TREATMENT
WATER USE EFFICIENCY (g grains/l)
WS 2010
DS 2011
Moisture Regimes (M)
Aerobic
0.17a 0.20a
Flooded
0.23b
0.14b
Varieties (V)


NSIC Rc 9
0.24a 0.21a
PSB Rc 14
0.18ab
0.09b
PSB Rc 68
0.13b
0.24a
NSIC Rc 136H
0.22a 0.20a
NSIC Rc192
0.23a 0.11b
M x V
0.62ns 2.84*
CVa (%)
3.19
0.00
CVb (%)
3.24
4.20
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).

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Effect of variety. Statistical analysis showed highly significant differences
among the rice varieties in terms of WUE during both seasons (Table 35). NSIC
Rc9 had the highest WUE during the wet season trialbut not significantly different
with NSIC Rc192 and NSIC Rc136H and comparable with PSB Rc14. PSB Rc68
had the lowest WUE.

During the dry season trial, PSB Rc68 had the highest water use efficiency
but not significantly different with NSIC Rc9 and NSIC Rc136H. PSB Rc14 had
the lowest water use efficiency.
Interaction effect. Statistical analysis revealed that there was no significant
interaction between the moisture regimes and the different rice varieties in terms of
water use efficiency during the wet season but a significant difference was noted
during the dry season trial (Table 35 and Figure 16). PSB Rc68 had the highest
water use efficiency both under aerobic and flooded conditions during the dry
season trial. The result implies that growing this variety under aerobic condition has
the ability of saving water without necessarily sacrificing yield.
 

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110 
 
0.30 
s
/
l)
0.25 
a
in
 
gr
0.20 
NSIC Rc9
c
y
 
(g
n 0.15 
c
i
e
PSB Rc14
ffi
 
e
PSB Rc68
e 0.10 
r
 
us
NSIC Rc136H
t
e 0.05 
NSIC Rc192
Wa
‐
Aerobic
Flooded
Soil Moisture Regimes

Figure 16. Interaction effect between the moisture regimes and the rice
varieties on water use efficiency in Luna, Apayao during the DS
2011
 
 
Reaction to Insect Pests and Diseases
Table 36 shows the insect and disease reaction in Luna, Apayao during the
wet season trial. Results show that all varieties grown under aerobic condition were
resistant to defoliators (caseworm and cutworm), stemborer, blast, and rat damages.
In flooded fields, all varieties were likewise resistant to stem borer and blast. PSB
Rc68 plants had intermediate resistance to both defoliators (caseworm and
cutworm) and rat damages.
During the dry season 2011, all varieties in both soil moisture regimes were
also resistant to defoliators (caseworm and cutworm) and stem borers (Table 37).
PSB Rc14 and NSIC Rc192 both in aerobic and flooded fields had shown

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Table 36. Reaction to pests of rice in Luna, Apayao during the WS 2010

SOIL
DEFOLIA-
DEAD-
WHITE-
RAT
MOISTURE
VARIETY
BLAST
TORS
HEARTS
HEADS
DAMAGE
REGIMES
NSIC Rc 9
Resistant
Resistant
Resistant Resistant Resistant
PSB Rc 14
Resistant
Resistant
Resistant Resistant Resistant
AEROBIC
PSB Rc 68
Resistant
Resistant
Resistant Resistant Resistant
NSIC Rc 136H
Resistant
Resistant Resistant Resistant Resistant
NSIC Rc 192
Resistant
Resistant Resistant Resistant Resistant
NSIC Rc 9
Moderately
Resistant Resistant Resistant Resistant
Resistant

PSB Rc 14
Moderately
Resistant Resistant Resistant Resistant
Resistant

FLOODED
PSB Rc 68
Intermediate
Resistant Resistant Resistant Resistant
NSIC Rc 136H
Moderately
Resistant Resistant Resistant Resistant
Resistant

NSIC Rc 192
Moderately
Resistant Resistant Resistant Resistant
Resistant

 
 
susceptibility to rice blast and rat damage, respectively. This could be attributed by
the amount of rainfall (2,070.5mm) and rainy days (15 days) during the dry season.
The early maturity of these varieties in relation to the others in the whole likewise
made these vulnerable to such pests.









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Table 37. Reaction to pests of rice in Luna, Apayao during the DS 2011

SOIL
DEFOLIA-
DEAD-
WHITE-
RAT
MOISTURE
VARIETY
BLAST
TORS
HEARTS
HEADS
DAMAGE
REGIMES
NSIC Rc9
Resistant
Resistant
Resistant Resistant Resistant
PSB Rc14
Resistant
Resistant
Resistant Susceptible Intermediate
AEROBIC
PSB Rc68
Resistant
Resistant
Resistant Resistant Resistant
NSIC Rc136H
Resistant
Resistant
Resistant Resistant
Intermediate
NSIC Rc 192
Resistant
Resistant
Resistant Resistant Susceptible
NSIC Rc 9
Resistant
Resistant Resistant Resistant Resistant

PSB Rc14
Resistant
Resistant Resistant Susceptible Intermediate

FLOODED
PSB Rc 68
Resistant
Resistant
Resistant Resistant Resistant
NSIC Rc136H
Resistant
Resistant
Resistant Resistant Resistant
NSIC Rc 192
Resistant
Resistant
Resistant Resistant Susceptible

 

Sensory Evaluation
Aroma. PSB Rc14 and NSIC Rc 136H had moderate aroma; PSB Rc68,
NSIC Rc192, and PSB Rc9 had slightly perceptible aroma (Table 38).
Taste. PSB Rc9, PSB Rc14, and NSIC Rc192 in both aerobic and flooded
fields had moderate taste. The rest had slightly tasty.
Texture. All four varieties, except PSB Rc68 in both soil moisture regimes,
had moderately soft grains. PSB Rc68 in aerobic fields had moderately soft but had
slightly hard grains in flooded plots.



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113 
 
Table 38. Sensory evaluation of rice in Luna, Apayao (2010-2011)

SOIL
GENERAL
MOISTURE
VARIETY AROMA TASTE
TEXTURE
ACCEPTABILITY
REGIMES
NSIC Rc 9
Slightly
Moderate Moderately
Like slightly
perceptible
Soft
PSB Rc 14
Moderate
Moderate
Moderately
Like very much
Soft
AEROBIC
PSB Rc 68
Slightly
Slightly
Moderately
Like moderately
perceptible
tasty
Soft
NSIC Rc 136H
Moderate
Slightly
Moderately
Like slightly
tasty
Soft
NSIC Rc 192
Slightly
Moderate Moderately Like moderately
perceptible
Soft
NSIC Rc 9
Moderate
Moderate
Moderately
Like slightly
Soft
PSB Rc 14
Moderate
Moderate
Moderately
Like moderately
Soft
FLOODED
PSB Rc 68
Slightly
Slightly
Like slightly
Slightly hard
perceptible
tasty
NSIC Rc 136H
Moderate
Moderate
Moderately
Like slightly
Soft
NSIC Rc 192
Slightly
Moderate Moderately Like moderately
perceptible
Soft
 
 
General Acceptability. PSB Rc14 in aerobic fields was liked very much by
evaluators. This variety grown under aerobic condition had moderate aroma and
moderately soft texture.

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Study 3: Growth and Yield Performance of Rice Grown under
Organic Production Two Moisture Regimes
inKapangan, Benguet


Agrometeorological Condition
 
 
Benguet province belongs to Type 1 climate which is characterized by two
pronounced seasons, dry from November to April and wet during the remaining
months of the year. The experiment site in Kapangan, Benguet has an elevation of
1,000 m asl. It is classified under high hills zone (500-1,000 m asl) according to
the Research, Development and Extension Agenda and Program for the Cordillera
Agro-Forest/Fishery Ecological Zones classification (DA-CAR, 1999). It also
falls under the irrigated (terraces) ecosystem based on rice ecosystem
classification (Dobermann and Fairhurst, 2000).
The total rainfall for wet season 2010 and dry season 2011 were 1,421.3
mm and 3,271.4 mm, respectively (Table 39 and 40). The minimum air
temperature during the study period ranged from 16.0oC-18.4oCwhile maximum
air temperature ranged from 24.9oC to 30.2oC. The temperature is within the
optimum range favorable for rice production of 18-40oC as cited by De Datta
(1981). The relative humidity in both cropping seasons ranged from 61.5 to
92.7%.



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115 
 
Table 39. Meteorological data in Kapangan, Benguet from October 2010 to
January 2011

CROPPING
RAINFALLa
RELATIVE
Tavg (oC)
SEASON/
(mm)
HUMIDITY
MONTH
%




October
261
71.5
30.0




November
333
75.0
30.5

December
25
61.5
31.0




January
97
72.5
28.5

a Rainfall accumulated from October 2010 to March 2011.


Table 40. Meteorological data in Kapangan, Benguet from March to October 2011

CROPPING
RAINFALLa RELATIVE
T
b
max
Tmin
Tavg
SEASON/
(mm)
HUMIDIT
(oC)
(oC)
(oC)
MONTH
Y
%






March
61.9
86.7
24.9
16.5
21.1






April
16.5
79.2
30.2
16.0
22.7






May
451.9
84.8
30.1
16.5
23.0






June
316.8
87.6
27.9
18.4
22.4


July
514.9
92.7
26.7
18.1
20.9






August
967.8
91.5
28.3
17.7
21.8






September
553.7
91.7
27.2
17.9
21.8






October
345.5
85.6
28.6
16.8
22.6

a Rainfall accumulated from July to March - October 2011.
bTmax, Tmin and Tavg refer to the means for the highest, lowest, and average temperature.

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Soil Properties

The the soil was slightly acidic at pH 6.1 (Table 40). De Datta (1981) cited
that the optimum pH for rice growth and development ranges from 5.5 to 6.5.
The soil in the site has a bulk density of 1.50 gcc-1 and water holding
capacity of 0.84 mlg-1. This bulk density is a typical characteristic of cultivated
sand loams and sands (Brady and Weil, 2002). It was stated further that root
growth into moist soil is generally limited by bulk densities ranging from 1.45
g/cc in clays to 1.85 g/cc in loamy sands.
 
Groundwater and Standing Water Depths
Figure 17 shows the depths of groundwater and standing water for aerobic
plots in Benguet from August 2010-October 2011. The water levels were almost
always below the soil surface indicating unponding. Rainfall during the two
cropping periods was supplemented with irrigation water whenever measurements
of standing water depth in two (2) out of the three (3) standing water tubes were at
20 cm below the soil surface. On the other hand, the groundwater depths were
measured using the 2-m tube installed in the aerobic plot. As cited by Brady and
Weil (2002), groundwater through capillary movement can provide a steady and
significant supply of water that enables plants to survive during periods of low
rainfallor when fields are not flooded (Boumanet al., 2007). Further, Bouman, et
al., (2007) cited that groundwater of less than 20 cm deep can provide a “hidden”
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes 
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Table 45. Soil physical and chemical properties in Kapangan, Benguet



SOIL PROPERTY
VALUE


Chemical Properties
pH
6.01


OM (%)
1.50


P2O5(ppm)
15.00


K20 (ppm)
98.0




Physical Properties


Bulk Density (g/cc)
1.50


Water Holding Capacity (ml/g)
0.84

 
 
 
et al., (2007) cited that groundwater of less than 20 cm deep can provide a
“hidden” source of water to the rice crop as the roots of the plants can directly
take up water from the ground.
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118 
 
20
)
0
m
‐20
 
(c
h
‐40
pt
e
‐60
r
 
d
t
e
‐80
Wa ‐100
‐120
t
 
6
c
 
8
r
 
3
 
5
 
7
 
26
g
t
 
9
 
30
g
 
25
t
 
15
t
 
27
 
19
r
 
24
 
15
e
t
 
18
t
p
c
 
29
g
 
28
Oc
v
 
17
e
De
n
Ap
n
n
l
y
 
17
Au
p
Oc
Au
Ja
Ju
Se
Oc
No
De
Ap
May
Ju
Ju
Au
Se
Oc
Month
GroundWater 
Standing water

Figure 17. Groundwater and standing water depths (cm) in aerobic fields in
Kapangan, Benguet (2010-2011)


Soil Matric Potential
The tensiometer reading started 3 weeks after seeding for the March-
November 2011 cropping season (Figure 18). When soil matric potential reached
10 cb, the aerobic plots were irrigated to a saturation point. During rainy months,
rainfall was supplemented with irrigation water. Therefore, the drop lines in the
figure indicate application of water either through irrigation or by rainfall.
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119 
 
12
10
8
s
ar
t
i
b
6
n
ce
4
2
0
Date

Figure 18. Soil matric potential (cb) in Kapangan,Benguet during the DS 2011


Plant Height at Maturity

Effect of water regimes. The water regimes significantly affected the plant
height at maturity (Table 42). Flooded plants were taller than the plants under
aerobic condition during the August 2010-February 2011 and March-November
2011growing periods.
Given the adequate water supply as reported by PhilRice (2007), good
crop establishment, normal crop growth and development and yield are ensured.
Further, De Datta (1981) cited that plant height generally increases with
increasing water depth.
Effect of variety. Plant height at physiological maturity differed
significantly among the varieties (Table 42). Sapaw (check variety) had the
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Table 42. Plant height of rice at maturity in Kapangan, Benguet during August
2010-February 2011 and March-November 2011

PLANT HEIGHT AT MATURITY (cm)
TREATMENT
Aug 2010-Feb 2011
Mar-Nov 2011
Soil Moisture Regimes (M)
Aerobic
73.51b 85.50b
Flooded
82.60a 102.67a
Varieties (V)
NSIC Rc 9
72.61b 90.65b
PSB Rc 14
63.48b 64.33e
PSB Rc 68
76.74b 87.49c
NSIC Rc 192
67.08b 73.91d
Sapaw
110.37a 154.04a
M x V
1.65ns
17.94**
CVa(%) 7.08
6.14
CVb(%) 12.12
2.40
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).

 
tallest plants on the August 2010-February 2011 and March-November 2011 at
110.38 cm and 154.04 cm, respectively. These results differed with that of Tad-
awan, et al., (2010) onSapaw’s height at maturity which measured 88.33 cm and
131.60 cm in Kapangan, Benguet during the 2009-2010 and 2010-2011 cropping
years, respectively.
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PSB Rc14 was consistently the shortest (63.38 and 64.33 cm) in both
growing periods which indicate that this is an inherent character of the variety.
Interaction effect. There was no interaction effect between the soil
moisture regimes and the rice varieties in terms of plant height on the WS but
there was significant interaction on the DS (Figure 19).Sapaw was the tallest in
both aerobic and flooded conditions. This indicates the adaptability of the
traditional variety to the area.
 
 
180.00 
160.00 
140.00 
)
m 120.00 
NSIC Rc9
t
 
(c
100.00 
i
g
h
PSB Rc14
80.00 
t
 
he
PSB Rc68
a
n
60.00 
Pl
NSIC Rc192
40.00 
Sapaw
20.00 
‐
Aerobic
Flooded
Soil Moisture Regimes


Figure 19. Interaction effect between the moisture regimes and the rice varieties
on plant height in Kapangan, Benguet during the DS


Number of Days from Seeding to Maximum Tillering,
Effect
of
moisture
regime. Statistical analysis showed no significant
difference between the two moisture regimes in terms of number of days from
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122 
 
seeding to maximum tillering during the August 2010-February 2011 cropping
season(Table 43) and significantly differed during March-November 2011 season
(Table 44). Results during the latter’s growing period show that under flooded
condition, plants produced the earlier maximum tiller than those grown under
aerobic condition.
Effect of variety. Highly significant differences were noted among the
different rice varieties in terms of number of days from seeding to maximum
tillering. NSIC Rc192 reached earliest the maximum tillering stage during the
August 2010-February 2011 and March-November 2011. The latest to produce
maximum tillers was Sapaw (Table 43 and 44).

The seeding to maximum stages are part of the vegetative phase of a rice
plant which mainly determines the differences in growth duration of varieties. As
cited by Arraudeau and Vergara (1988), the duration of vegetative phase differs
with variety.
Interaction effect. There was no significant interaction observed during the
August 2010-February 2011 cropping season in Kapangan, Benguet but had
significant interaction effect in March-November 2011 season(Figure 19). Under
both soil moisture regimes, NSIC Rc192 produced maximum tillers earliest. The
result confirmed that NSIC Rc192 is an early maturing variety (PhilRice, 2009).

 
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Table 43. Number of days from seeding to maximum tillering, maximum tillering
to booting, booting to heading, and heading to maturity of rice in
Kapangan, Benguet during the August 2010-February 2011

NUMBER OF DAYS FROM:
SEEDING
MAXIMUM
TREATMENT
BOOTING
HEADING
TO
TILLERING
TO
TO
MAXIMUM
TO
HEADING MATURITY
TILLERING
BOOTING
Moisture Regimes (M)

Aerobic
60.85
28.75
14.45
49.75b
Flooded
60.85
28.55
14.65
36.60a
Varieties (V)




NSIC Rc 9
56.75
28.50b
14.75b
42.00
PSB Rc 14
56.70
26.88b
12.63a
41.00
PSB Rc 68
66.50
30.63c
14.88b
44.00
NSIC Rc 192
55.25
21.50a
12.25a
41.50
Sapaw
70.25 35.75d
18.25c
47.38
M x V
0.00
0.31ns
2.39ns
1.28ns
CVa (%)
0.00
2.38
4.70
13.12
CVb (%)
2.30
5.70
4.10
11.47
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).




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124 
 
Table 44. Number of days from seeding to maximum tillering, maximum tillering
to booting, booting to heading, and heading to maturity of rice in
Kapangan, Benguet during the March-November 2011

NUMBER OF DAYS FROM:
SEEDING
MAXIMUM
TREATMENT
BOOTING
HEADING
TO
TILLERING
TO
TO
MAXIMUM
TO
HEADING MATURITY
TILLERING
BOOTING
Moisture Regimes (M)

Aerobic
85.85b
34.50b
16.50
47.80a
Flooded
76.55a
30.30a
16.70
52.70b
Varieties (V)




NSIC Rc 9
74.25c
33.38b
16.75b
51.50c
PSB Rc 14
70.75b
27.38a
14.75a
44.13a
PSB Rc 68
81.50d
32.75b
16.88b
48.38b
NSIC Rc192
64.25a
25.75a
14.38a
52.63cd
Sapaw
115.25e
42.75c
20.25c
54.75d
M x V
52.33**
1.80ns
2.38ns
7.39**
CVa (%)
0.39
11.32
3.81
4.80
CVb (%)
1.80
8.00
3.30
3.86
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).

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125 
 
140.00 
120.00 
100.00 
y
s
 
da
NSIC Rc9
80.00 
 
of
er
PSB Rc14
b
60.00 
m
PSB Rc68
Nu
40.00 
NSIC Rc192
20.00 
Sapaw
‐
Aerobic
Flooded
Soil Moisture Regimes
 
Figure 19. Interaction effect between the soil moisture regimes and the rice
varieties on number of days from seeding to maximum tillering in
Kapangan, Benguet during the DS 2011


Number of Days from Maximum Tillering to Booting
Effect of moisture regime. Statistical analysis showed no significant
difference between the two moisture regimes in terms of number of days from
maximum tillering to booting stage in Kapangan, Benguet during the August
2010-February 2011 (Table 43) and significantly differed during the March-
November 2011 (Table 44). Results showed that under flooded condition, plants
had booting stage earlier than those grown under aerobic condition both during
the two growing periods.
Effect of variety. Significant differences were noted among the different
rice varieties in terms of number of days from maximum tillering to booting stage.
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126 
 
NSIC Rc192 reached booting stage from maximum tillering earliest during the
August 2010-February 2011 and March-November 2011 with a mean of 21.50
days and 25.75 days, respectively. PSB Rc14 (27.38 days) was not significantly
different with NSIC Rc192 in August 2010-February 2011. The latest to reach
booting stage was Sapaw at 35.75 days and 42.75 days for the August 2010-
February 2011 and March-November 2011 growing seasons, respectively (Table
43 and 44).
Interaction effect. There was no significant interaction observed between
the soil moisture regimes and the rice varieties both during the two cropping
seasons in Kapangan, Benguet (Table 43 and 44).
 
Number of Days from Booting to Heading
Effect of moisture regime. Statistical analysis showed no significant
difference between the two moisture regimes in terms of number of days from
booting to heading stage in Kapangan, Benguet both during the August 2010-
February 2011 and March-November 2011 (Table 43 and 44).
Effect of variety. Significant differences were noted among the different
rice varieties in terms of number of days from booting to heading stage (Table
43and 44). NSIC Rc192 reached heading from booting stage earliest during the
August 2010-February 2011cropping season with a mean of 12.25 days which
was not significantly different with PSB Rc14 at 12.63 days. For March-
November 2011 growing period, NSIC Rc192 likewise had the shortest days to
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heading at 14.38 which was not significantly different with PSB Rc14 at 14.75
days. The Sapaw was the latest during the August 2010-February 2011 and
March-November 2011growing periods at 18.2 days and 20.25 days, respectively.
The results indicated that NSIC Rc192 and Sapaw had consistently the earliest
and latest vegetative and reproductive phases in Kapangan, Benguet, respectively.
Interaction effect. There was no significant interaction observed between
the soil moisture regimes and the rice vareties both during the August 2010-
February 2011 and March-November 2011 cropping seasons in Kapangan,
Benguet (Table 43 and 44).

Number of Days from Heading to Maturity


Effect of water regime.Plants under flooded conditionmatured earlier than
under aerobic plots during the August 2010-February 2011 growing period (Table
43 and 44). Conversely, plants matured earlier from heading in aerobicthan in the
flooded plots during the March-November 2011 cropping season.
Effect of variety. It was observed that there was no significant difference
among the varieties on the number of days from heading to maturity during the
August 2010-February 2011but did not significantly differamong the varieties
during the March-November 2011 cropping season(Table 43 and 44). For the
March-November 2011 cropping season, PSB Rc14 matured earliest than the rest
of the varieties from heading stage whileSapawmatured latest.
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Interaction
effect. There was no significant interaction on the August
2010-February 2011cropping season but on March-November 2011, it was
observed that there was a high interaction between the soil moisture regimes and
the rice varieties on number of days from heading to maturity (Figure 21). The
result shows that PSB Rc14 matured from heading stage earliest under both soil
regimes in Kapangan, Benguet.

Leaf Area Index (LAI) at 75 Days After Sowing (DAS)


Effect of moisture regime. Plants grown under flooded plots had higher
LAI than plants grown under aerobic plots in both cropping seasons (Table 45).
 
 
60.00 
50.00 
y
s 40.00 
 
da
NSIC Rc9
30.00 
e
r
 
of
PSB Rc14
mb
PSB Rc68
20.00 
Nu
NSIC Rc192
10.00 
Sapaw
‐
Aerobic
Flooded
Soil Moisture Regimes


Figure 21. Interaction effect between the moisture regimes and the rice varieties
on number of days from heading to maturity in Kapangan, Benguet
during the March-November 2011 growing season



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129 
 
Table45. Leaf area index of rice at 75 DAS in Kapangan, Benguet during the WS
2010 and DS 2011

TREATMENT
LEAF AREA INDEX AT 75 DAS
Aug 2010-Feb 2011
Mar-Nov 2011
Soil Moisture Regimes (M)
Aerobic
0.63b 3.24b
Flooded
1.25a 5.25a
Varieties (v)
NSIC Rc 9
0.97
4.26
PSB Rc 14
1.01
3.41
PSB Rc 68
0.95
4.54
NSIC Rc 192
1.01
4.27
Sapaw
0.76 4.76
M x V
1.13ns 0.23ns
CVa (%)
13.95
10.18
CVb (%)
10.81
12.77
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).

 

The result agrees with that of Bouman et al., (2005) that there is a reduced
leaf area in rice plants under aerobic than flooded condition.

Effect of variety. Table 45 shows no significant difference among the rice
varieties in terms of LAI at 75 DAS on both cropping seasons. Plants of PSBRc14
and NSIC Rc192 had the highest LAI on August 2010-February 2011 each at
1.01. Sapaw had the lowest LAI during the August 2010-February 2011 cropping
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season and highest during the March-November 2011 at 0.76 and 4.76,
respectively.
Interaction effect. There was no significant interaction between the soil
moisture regimes and the rice varieties on LAI at 75 DAS for both cropping
seasons (Table 45).

Panicle Number at Maturity


Effect of moisture regime.There was a significant difference observed
between the moisture regimes in terms of panicle number at maturity in
Kapangan, Benguet during the August 2010-February 2011, while there was no
significant differencenoted during the March-November 2011 (Table 46). Plants
grown in flooded fields produced more panicles than the plants grown in aerobic
plots for both cropping seasons.
The results agree with the findings in Lagangilang, Abra and Luna,
Apayao (for WS 2010) that panicle number in aerobic plots are higher than in
flooded fields. The foregoing results agree with that of Kato, et. al (2006) that
there was a reduction in panicle number of some cultivars produced under
suboptimal water condition like in aerobic rice. However, Abbasi and Sepaskhah
(2010) noted that the effect of water stress prolonged the growth duration of rice
cultivars in intermittent flood irrigation similar with aerobic rice resulted in higher
number of panicles.

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Table 46. Panicle number at maturity in Kapangan, Benguet during the August
2010-February 2011 and March-November 2011cropping periods

PANICLE NUMBER AT MATURITY
TREATMENT
Aug 2010-Feb 2011
Mar-Nov 2011
Soil Moisture Regimes (M)
Aerobic
28.00b
42.80
Flooded
36.40a
52.75
Varieties (V)
NSIC Rc 9
33.00
46.25ab
PSB Rc 14
36.25
60.13a
PSB Rc 68
35.13
41.00bc
NSIC Rc 192
29.50
61.38a
Sapaw
27.25 30.13c
M x V
2.28ns
1.57ns
CVa (%)
3.67
6.35
CVa (%)
6.62
6.07
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).

 
Effect of variety. There was no significant difference among the rice
varieties on panicle number at maturity during the August 2010-February 2011 as
observed in Table 46 but differed significantly during the March-November 2011
cropping period. NSIC Rc192 produced the highest panicles but comparable with
PSB Rc14. Sapaw produced the least number of panicles. The results show the
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132 
 
tillering ability of the high yielding varieties like NSIC Rc192 and PSB Rc14 over
the traditional variety Sapawunder organic rice production system.
Interaction effect. Table 46 shows that there was no significant interaction
between the moisture regimes and the varieties in terms of panicle number in
Kapangan, Benguet both during the two cropping seasons (2010-2011).

Panicle Length
Effect of soil moisture regime. Statistical analysis showed no significant
differences between the two moisture regimes in terms of panicle length in
Kapangan, Benguet during the August 2010-February 2011 and March-November
2011cropping periods (Table 47). Plants grown under flooded condition produced
longer panicles than plants under aerobic condition during the August 2010-
February 2011 and March-November 2011cropping season at 19.31 cm and 19.72
cm, respectively.
Effect of variety. Significant differences were observed among the rice
varieties in terms of panicle length in Kapangan, Benguet during August 2010-
February 2011 and March-November 2011 (Table 47). Sapaw significantly
produced the longest panicles during the August 2010-February 2011 and March-
November 2011cropping seasons with a mean of 23.79 and 24.11 cm,
respectively. NSIC Rc192 produced the shortest panicles with a mean of 15.89 cm
and 17.26 cm for August 2010-February 2011 and March-November
2011cropping seasons, respectively.
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Table 47. Panicle length (cm) of rice in Kapangan, Benguet during the August
2010-February 2011 and March-November 2011cropping periods

PANICLE LENGTH (cm)
TREATMENT
Aug 2010-Feb 2011
Mar-Nov 2011
Soil Moisture Regimes (M)
Aerobic
18.28
19.33
Flooded
19.31
19.72
Varieties (V)
NSIC Rc 9
18.94b 20.21b
PSB Rc 14
17.56b 17.76b
PSB Rc 68
17.80b 18.28b
NSIC Rc 192
15.89c 17.27b
SAPAW
23.79a 24.11a
M x V
3.33ns
2.02ns
CVa (%)
10.11
12.64
CVb (%)
5.24
10.14
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).


Interaction effect. Statistical analysis showed no significant interaction
between the soil moisture regimes and the rice varietieson panicle length (Table
47).
 
 
 
 
 
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134 
 
Total Number of Grains per Panicle

Effect of water regimes. Table 48 shows the total number of grains per
panicle in Kapangan, Benguet. On both cropping seasons, there was no significant
difference observed between the two moisture regimes on number of filled grains
per panicle.

Effect of variety. The total number of grains per panicle was significantly
different among the rice varieties(Table 48). Sapaw had the highest number of
grains per panicle for both August 2010-February 2011 and March-November
2011 cropping periods. For the former season, Sapaw was comparable with PSB
Rc14, NSIC Rc192 and NSIC Rc9. During the March-November 2011 cropping,
grain number ofSapaw was comparable with NSIC Rc9.PSB Rc68 and PSB Rc14
had the lowest number of grains per panicle during the August 2010-February
2011 and March-November 2011cropping seasons, respectively.
Interaction effect. No significant interaction between the moisture regimes
and the rice varieties in terms of total number of grains per panicleduring the
August 2010-February 2011 butdiffered significantly during the March-
November 2011cropping season (Figure 22). The foregoing result shows that
Sapaw had the most grains per panicle under both soil moisture regimes. This
implies the adaptability of Sapaw in the locality and its superiority over the high
yielding varieties regardless of soil moisture regimes and under organic
production system.
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes 
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135 
 
 
Table 48. Total number of grains per panicle in Kapangan, Benguet during the
August 2010-February 2011 and March-November 2011 cropping
periods

TREATMENT
TOTAL NUMBER OF GRAINS PER PANICLE
AUG 2010-FEB 2011
MAR-NOV 2011
Soil Moisture Regimes (M)
Aerobic
116.05
98.90
Flooded
126.35
96.90
Varieties (V)
NSIC Rc 9
118.13ab
110.00ab
PSB Rc 14
121.25ab
77.50c
PSB Rc 68
107.50b
82.50c
NSIC Rc 192
118.25ab
94.00bc
Sapaw
140.88a
125.50a
M x V
1.08ns
24.20**
CVa (%)
4.82
6.46
CVb (%)
3.42
11.58
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).



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136 
 
180.00 
160.00 
i
c
l
e
an 140.00 
s
/
p
n 120.00 
NSIC Rc9
 
g
r
ai 100.00 
PSB Rc14
r
 
of
80.00 
be
PSB Rc68
60.00 
NSIC Rc192
40.00 
t
a
l
 
num
20.00 
Sapaw
To
‐
Aerobic
Flooded
Soil Moisture Regimes


Figure 22. Interaction effect between the moisture regimes and the varieties on
total number of grains per panicle in Kapangan, Benguet during the
March-November 2011


Number of Filled Grains per Panicle


Effect of water regimes. Table 49 shows the number of filled grains per
panicle in Kapangan, Benguet during the August 2010-February 2011 and March-
November 2011cropping seasons. On both seasons, there was no significant
difference observed between the two moisture regimes on number of filled grains
per panicle. Higher filled grain ratio was observed in plants under flooded
condition during the August 2010-February 2011 but higher under aerobic than
flooded plots during the March-November 2011.

Effect of variety. Significant differences were found among the rice
varieties in terms of the number of filled grains per panicle (Table48). Sapaw had
the most filled grains per panicle for both August 2010-February 2011 and
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes 
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Table 49. Number of filled grains per panicle inKapangan, Benguet during the
August 2010-February 2011 and March-November 2011 cropping
periods

NUMBER OF FILLED GRAINS PER
TREATMENT
PANICLE
AUG 2010-FEB 2011
MAR-NOV 2011
Soil Moisture Regimes (M)
Aerobic
88.00
72.00
Flooded
93.00
59.00
Varieties (V)
NSIC Rc 9
95.00b
86.00a
PSB Rc 14
80.00b
45.00b
PSB Rc 68
83.00b
57.00b
NSIC Rc 192
78.00b
55.00b
SAPAW
118.00a
86.00a
M x V
5.79**
40.04**
CVa (%)
4.87
3.96
CVb (%)
2.98
2.60
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).


March-November 2011cropping season at 118 and 86, respectively. NSIC Rc192
and PSB Rc14 had the lowest number of filled grains per panicle in Kapangan,
Benguet during the August 2010-February 2011 and March-November
2011cropping season, respectively.
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138 
 
Interaction effect. There were significant interactions noted between the
moisture regimes and the rice varieties in terms of number of filled grain per
panicle in Kapangan, Benguet on both cropping seasons (Figure 23 and 24). For
August 2010-February 2011, Sapaw had the most filled grains per panicle under
both soil moisture regimes. During the March-November 2011 cropping period,
Sapaw maintained as the highest on number of filled grains per panicle under
aerobic condition and NSIC Rc9 in flooded plots. These results showed the
adaptability of the traditional variety Sapaw over the high yielding varieties.
 

160.00 
i
c
l
e
n 140.00 
r
 
pa 120.00 
s
 
pe 100.00 
NSIC Rc9
a
in
80.00 
PSB Rc14
 
gr
d
l
e
60.00 
PSB Rc68
 
fil
 
of
40.00 
NSIC Rc192
er
b
20.00 
Sapaw
m
Nu
‐
Aerobic
Flooded
Soil Moisture Regimes


Figure 23. Interaction effect between the moisture regimes and the varieties on
number of filled grains per panicle in Kapangan, Benguet during the
August 2010-February 2011


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139 
 
140.00 
c
l
e
ni 120.00 
r
 
pa
100.00 
s
 
pe
NSIC Rc9
80.00 
a
i
n
PSB Rc14
 
gr
d
60.00 
e
PSB Rc68
 
f
ill
40.00 
 
of
NSIC Rc192
er
20.00 
Sapaw
mb
Nu
‐
Aerobic
Flooded
Soil Moisture Regimes

Figure 24. Interaction effect between the moisture regimes and the rice varieties
on number of filled grains per panicle in Kapangan, Benguet during
the March-November 2011


Filled Grain Ratio

Effect
of
moisture
regime.Table50 shows no significant differences
between the two moisture regimes on the filled grain ratio during theAugust 2010-
February 2011 but had differed significantly during the March-November 2011in
Kapangan, Benguet. The different rice varieties grown under aerobic fields had
higher filled grainratio as compared to the plants grown under flooded plots. The
results contradicted with the filled grain ratio in Luna, Apayao where higher rate
was noted under flooded than under aerobic condition.

Effect of variety. Results showed that there were no significant differences
among the varieties during the August 2010-February 2011 cropping season on
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140 
 

Table 50. Filled grain ratio (%) of ricein Kapangan, Benguet during the August
2010-February 2011 and March-November 2011 cropping periods

FILLED GRAIN RATIO (%)
TREATMENT
AUG 2010-FEB 2011
MAR-NOV 2011
Soil Moisture Regimes (M)
Aerobic
76.61
70.29a
Flooded
68.55
61.36b
Varieties (V)
NSIC Rc 9
80.25
77.65a
PSB Rc 14
65.81
58.84c
PSB Rc 68
77.05
69.39b
NSIC Rc 192
66.38
57.84c
Sapaw
73.41 65.40bc
M x V
0.24ns 8.76**
CVa (%)
15.99
6.76
CVb (%)
17.10
8.18
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).


the filled grain ratio (Table 50). For the March-November 2011 growing period,
there were significant differences among the varieties on the filled grain ratio.
NSIC Rc9 had the highest filled grain ratio of 80.25% and 77.65 % during the
August 2010-February 2011andMarch-November 2011, respectively. On the
other hand, PSB Rc14 and NSIC Rc192 obtained the lowest filled grain ratio with
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141 
 
a mean of 65.81% and 57.84% for the August 2010-February 2011andMarch-
November 2011, respectively.

These results were consistent with the outcome during the dry season 2011
in Lagangilang, Abra and Luna, Apayao that NSIC Rc9 has the highest filled
grain ratio. This implies that NSIC Rc9 has inherent character of having a high
filled grain ratio even under organic production system.
Interaction
effect. There was no significant interaction effect between
moisture regimes and varieties in terms of filled grain ratio in Kapangan, Benguet
during the August 2010-February 2011 cropping season but there was a highly
significant interaction on March-November 2011 (Table 50). NSIC Rc9 had the
highest filled grain ratio (81.33% and 73.98%) under aerobic and flooded
condition, respectively (Figure 25). This implies that NSIC Rc9 can be grown
under both soil moisture regimes in Kapangan, Benguet even under organic
production system.


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142 
 
90.00 
80.00 
) 70.00 
 
(% 60.00 
t
i
o
NSIC Rc9
 
ra 50.00 
PSB Rc14
a
i
n 40.00 
 
gr
PSB Rc68
d 30.00 
l
l
e
Fi
NSIC Rc192
20.00 
10.00 
Sapaw
‐
Aerobic
Flooded
Soil Moisture Regimes


Figure 25. Interaction effect between the moisture regimes and the varieties on
filled grain ratio in Kapangan, Benguet during the March-November
2011 cropping season


1000 Grain Weight


Effect of moisture regime. There was no significant difference between
the two water regimes on the 1000-grain weight during the August 2010-February
2011 and March-November 2011 cropping seasons (Table 51).
Effect of variety. Results showed that there were significant differences
among the rice varieties in terms of 1000-grain weight during the August 2010-
February 2011 and March-November 2011 cropping period (Table 51). Sapaw
produced the highest grain weight in both cropping periods. Sapaw is comparable
with PSB Rc 68 during the August 2010-February 2011 only but the lowest
weight was obtained from NSIC Rc192 on the August-February 2012 season and
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Table 51. 1000-grain weight (g)of rice inKapangan, Benguet during the August
2010-February 2011 and March-November 2011 cropping periods

1000 GRAIN WEIGHT(g)
TREATMENT
AUG 2010-FEB 2011
MAR-NOV 2011
Soil Moisture Regimes (M)
Aerobic
25.60
18.44
Flooded
25.53
18.57
Varieties (M)
NSIC Rc 9
23.00b 16.66c
PSB Rc 14
23.66b 14.41d
PSB Rc 68
29.11a 19.76b
NSIC Rc 192
22.88b 16.73c
Sapaw
29.18a 24.95a
M x V
1.33ns 9.54**
CVa (%)
0.76
13.30
CVb (%)
3.98
5.96
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
PSB Rc14 on the March-November 2011 season with a mean of 22.88 g and
14.41g, respectively. The results implied that on the basis of 1000-grain weight as
a selection index, Sapaw and NSIC Rc68 can be grown under organic rice
production system in Kapangan, Benguet.
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Interaction effect. There was no interaction effect between water regimes
and varieties on the 1000 grain weight in Benguet during the August 2010-
February 2011 cropping periodbut had significant interaction effect during
theMarch-November 2011cropping season (Figure 26).Sapaw produced the
heaviest 1000 filled grains both under aerobic and flooded condition. This implies
that Sapaw produces high grain weight even under organic rice production.

 
30.00 
25.00 
)
20.00 
i
g
h
t
 
(g
NSIC Rc9
15.00 
PSB Rc14
a
i
n
 
we
‐
gr
PSB Rc68
10.00 
NSIC Rc192
1000
5.00 
Sapaw
‐
Aerobic
Flooded
Soil Moisture Regimes


Figure 26. Interaction effect between the moisture regime and variety on 1000-
grain weight in Kapangan, Benguet during the March-November
2011 cropping period


Total Dry Matter Weight


Effect of moisture regime. There was a significant difference between the
two moisture regimes on the dry matter weight during the August 2010-February
2011 and March-November 2011 cropping periods (Table 52). Flooded plants
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145 
 
significantly recorded a higher dry matter weight during the August 2010-
February 2011 and March-November 2011 cropping periodat 94.23 g and 135.04
g, respectively.

The results agree with the findings of Lafitte and Benett (2002) that low
dry matter weight under aerobic condition may be related to the relatively shallow
root system and stomata closure which consequently reduced photosynthesis in
response to surface soil drying. Further, Kato et al., (2006a) also cited that in
general, the total dry matter increases with increasing water supply.
Effect of variety. Dry matter weight during the August 2010-February
2011 and March-November 2011 cropping periods were significantly influenced
by the varieties (Table 52). For the August 2010-February 2011 season, PSB
Rc68 obtained the highest dry matter weight of 83.94 g which was comparable
with Sapawat 81.31 g. The lowest dry matter weight was observed on NSIC
Rc192 with a mean of 55.44g. For the dry March-November 2011 cropping
period, Sapaw produced the highest dry matter weight of 146.41g which was
comparable with NSIC Rc9 at 118.54g. The lowest dry matter weight was
obtained from PSB Rc 14 with a mean of 70.55g.
It can be noted that Sapaw and NSIC Rc9 were tall varieties in both
cropping periods. The same varieties had high total dry matter weight. This
therefore implies that tall varieties have high dry matter.

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146 
 
Table 52. Dry matter weight (g) of rice in Kapangan, Benguet during the August
2010-February 2011 and March-November 2011 cropping periods

DRY MATTER WEIGHT (g)
TREATMENT
AUG 2010-FEB 2011
MAR-NOV 2011
Soil Moisture Regimes (M)
Aerobic
49.98b 73.42b
Flooded
94.23a 135.04a
Varieties
NSIC Rc 9
68.06b 118.54ab
PSB Rc 14
71.75ab 70.55b
PSB Rc 68
83.94a 96.91ab
NSIC Rc 192
55.44c 88.73ab
Sapaw
81.31a 146.41a
M x V
10.26**
0.42ns
CVa (%)
16.99
3.93
CVb (%)
11.43
5.46
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).

 
Interaction effect. For the August 2010-February 2011 season March-
November 2011 cropping period, results showed that there was significant
interaction between the moisture regimes and the rice varieties on the dry matter
weight (Figure 27) but had no significant interaction during the March-November
2011 cropping period (Table 52). Sapaw had the highest total dry matter weight
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes 
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under aerobic condition and PSB Rc68 under flooded condition during the August
2010-February 2011 cropping period.
The result corroborates that of Kato et al (2006a) that a cultivar-water
regime interaction in total dry matter weight exists. It wasearlier shown that
different cultivars responded differently to the water conditions and that the local
water supply greatly affected the total dry matter in upland conditions through its
effects on the amount of N uptake, which was associated with the depth of root
development.
 
 
140.00 
120.00 
)
t
 
(g 100.00 
i
g
h
NSIC Rc9
80.00 
r
 
we
PSB Rc14
t
t
e
60.00 
PSB Rc68
y
 
ma
40.00 
NSIC Rc192
Dr
20.00 
Sapaw
‐
Aerobic
Flooded
Soil Moisture Regimes


Figure 27. Interaction effect between the moisture regimes and the varieties on
dry matter weight in Kapangan, Benguet during the WS 2010






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Harvest Index


Effect of moisture regime. There was no significant difference between
the two moisture regimes on harvest index during the August 2010-February 2011
but significantly influenced the harvest index on the March-November 2011
cropping period (Table 53). Plants under aerobic obtained a higher harvest index
during the August 2010-February 2011 and March-November 2011 cropping
seasons at 34.79 and 27.12, respectively.

The resultsare in agreement of various researchers (Yang et al., 2000; Guo
et al., 2004; Kemanian et al., 2007; D’Andrea et al., 2008; Pelton-Sainio et al.,
2008; Xue et al., 2006; Zhang et al., 2008b; Bueno and Lafarge, 2009; Fletcher
and Jamieson, 2009; Ju et al., 2009) as cited by Yang and Zhang (2010) that
variations in harvest index within a crop are mainly attributed to differences in
crop management such as water and/or nitrogen management system that could
increase growth rate during grain growth and/or enhance the remobilization of
assimilates from vegetative tissues to grains during the grain-filling period usually
leads to a higher harvest index. Among the water management systems cited were
alternate wetting and moderate soil drying regimes during the whole growing
season similar to aerobic rice.
Effect of variety. Results show that there were significant differences
among the rice varieties in terms of harvest index during the August 2010-

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Table 53. Harvest index of rice in Kapangan, Benguet during the August 2010-
February 2011 and March-November 2011 cropping periods

TREATMENT
HARVEST INDEX
AUG 2010-FEB 2011
MAR-NOV 2011
Soil Moisture Regimes (M)
Aerobic
0.35
0.27a
Flooded
0.33
0.15b
Varieties (V)
NSIC Rc 9
0.34ab 0.18b
PSB Rc 14
0.31b 0.22ab
PSB Rc 68
0.37a 0.24a
NSIC Rc 192
0.31b 0.21ab
Sapaw
0.38a 0.22ab
M x V
2.32ns 1.15ns
CVa (%)
11.78
5.39
CVb (%)
11.22
5.64
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).

 
February 2011 and March-November 2011 cropping seasons (Table 53). For the
August 2010-February 2011 season, Sapaw obtained the highest harvest indexof
0.38 which is comparable with PSB Rc68 at 0.37. ForMarch-November 2011
cropping period, PSB Rc68 produced the highest harvest index (0.24) comparable
with Sapaw (0.22), PSB Rc14 (0.22) and NSIC Rc192 (0.21).
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The results indicate that both Sapaw and PSB Rc68 had consistently high
harvest index for the two cropping seasons under organic production system. This
implies that the grain yield of these varieties can be enhanced further by
improving their harvest indices through the application of soil nutrient
amendments following the organic approach.
Interaction effect. There was no significant interaction effect between
water regimes and varieties on the harvest index during both cropping periods
(Table 53).

Grain Yield


Effect of moisture regime. There was a significant difference between the
two water regimes on the grain yieldin Kapangan, Benguet during the August
2010-February 2011 season but noneduring the March-November 2011(Table
54). Flooded recorded a higher grain yield on the August 2010-February 2011
season with a mean of 1.43 kg/5.75 m2 but a higher yield under aerobic plots
during theMarch-November 2011season at 0.15 kg/5.75 m2.
Effect of the variety. Significant differences exist among the varieties on
both the August 2010-February 2011and March-November 2011cropping seasons
(Table 54). PSB Rc68 significantly produced the highest yield of 1.29 kg/5.75
m2on August 2010-February 2011season which was comparable with NSIC Rc9
(1.16 kg/5.75 m2) and Sapaw (1.15 kg/5.75 m2). The lowest yield was obtained
from NSIC Rc192 with a mean of 0.68 kg/5.75 m2. For the March-
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Table 54 Grain yield in rice production in Kapangan, Benguet during the August
2010-February 2011 and March-November 2011 cropping periods

GRAIN YIELD (kg/5.75 m2-1)
TREATMENT
AUG 2010-FEB 2011
MAR-NOV 2011
Soil Moisture Regimes (M)
Aerobic
0.61b 0.15
Flooded
1.43a 010
Varieties (V)
NSIC Rc 9
1.15ab 0.08b
PSB Rc 14
0.83bc 0.08b
PSB Rc 68
1.29a 0.04b
NSIC Rc 192
0.67c 0.09b
Sapaw
1.15ab 0.35a
M x V
3.56*
7.11**
CVa (%)
2.50
7.64
CVb (%)
4.14
8.28
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).
 
 
November 2011cropping season, Sapaw recorded the highest yield while PSB
Rc68 had the lowest.
Interaction
effect. The interaction effect between water regimes and
varieties was significant on both the August 2010-February 2011and March-
November 2011cropping seasons (Figures28 and29). For August 2010-February
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2011 season, NSIC Rc9 produced the highest grain yield of 0.74 kg 5.75 m2-
1under aerobic condition and PSB Rc68 at 1.85 kg 5.75 m2-1 under flooded
condition (Figure 28). During the March-November 2011 cropping period, Sapaw
attained the highest grain yield at 0.48 kg 5.75 m2-1 and 0.23 kg 5.75 m2-1under
aerobic and flooded fields (Figure 29).

The results imply seasonality of varieties based on grain yield under both
soil moisture regimes grown under organic production in Kapangan, Benguet
namely NSIC Rc9 and PSB Rc68 for August-February and Sapaw during the
March-November cropping period. This likewise indicated the adaptability of
these varieties to the locality.
 
 
2.00 
1.80 
1.60 
 
m2)
75 1.40 
NSIC Rc9
1.20 
1.00 
PSB Rc14
t
 
(
k
g
/
5.
i
g
h 0.80 
PSB Rc68
 
we 0.60 
NSIC Rc192
a
i
n 0.40 
Gr
Sapaw
0.20 
‐
Aerobic
Flooded
Soil Moisture Regimes

Figure 28. Interaction effect between the moisture regimes and the rice varieties
on grain yield in Kapangan, Benguet during the August 2010-
February 2011 cropping period
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153 
 
0.60 
0.50 
 
m2)
75 0.40 
NSIC Rc9
PSB Rc14
0.30 
t
 
(
k
g
/
5.
i
g
h
PSB Rc68
0.20 
 
we
NSIC Rc192
a
i
n
Gr 0.10 
Sapaw
‐
Aerobic 
Flooded
Soil Moisture Regimes

Figure 29. Interaction effect between the moisture regimes and the varieties on
grain yield in Kapangan, Benguet during the March-November
2011 cropping period


Computed Yield


Effect of moisture regime. The computed yield per hectare during the
August 2010-February 2011 cropping period was significantly influenced by the
moisture regimes as shown in Table 55. Computed yield from flooded field was
higher at 2.38 t/ha than in aerobic plots at 1.05 t/ha.For the March-November
2011 cropping season, results showed that there was no significant effect between
the two moisture regimes on the computed yield per hectare.
Effect of variety. Yield significantly differed among the varieties during
both cropping seasons(Table 55). On the August 2010-February 2011, PSB Rc68
significantly produced the highest computed yield of 2.24 t ha-1 which was
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Table 55. Computed yield (t ha-1) of rice inKapangan, Benguet during the August
2010-February 2011 and March-November 2011 cropping periods

COMPUTED YIELD (t ha-1)
TREATMENT
AUG 2010-FEB 2011
MAR-NOV 2011
Soil Moisture Regimes (M)
Aerobic
1.05b 0.26
Flooded
2.48a 0.18
Varieties (V)
NSIC Rc 9
1.99ab 0.15b
PSB Rc 14
1.43bc 0.13b
PSB Rc 68
2.24a 0.07b
NSIC Rc 192
1.16c 0.16b
SAPAW
2.01ab 0.62a
M x V
3.61*
7.21**
CVa(%) 9.76
3.84
CVb(%) 9.71
4.27
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).


was comparable with Sapaw (2.01 t ha-1) and NSIC Rc9 (1.99 tha-1). For the
March-November 2011 cropping season, Sapaw produced the highest computed
yield with a mean of 0.62 tha-1 while the lowest was obtained from PSB Rc68 at
0.07 t ha-1.
These results imply that PSB Rc68, Sapaw, and NSIC Rc9 can be grown
under organic production during the August-February cropping period. With
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155 
 
improved cultural management practices such as the application of soil nutrient
amendments to further enhance harvest index and eventually yield levels under
Kapangan, Benguet condition.
Interaction effect. There was significant interaction effect between
moisture regimes and varieties evaluated on the computed yield per hectare for
both cropping seasons. During the August 2010-February 2011, NSIC Rc9 and
PSB Rc68 produced the highest computed yield under aerobic and flooded
conditions, respectively(Figure 30).For March-November 2011, Sapaw had the
highest yield on both soil moisture regimes.
The results indicate that NSIC Rc9 and PSB Rc68 can be grown under
organic production in Kapangan, Benguet during the August-February cropping
period; and Sapaw during the March-November growing season. The current
yield levels can still be improved by using soil amendments in accordance with
the principles of organic production system.

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156 
 
3.50 
3.00 
a
)
/
h 2.50 
 
(t
NSIC Rc9
l
d 2.00 
 
yie
PSB Rc14
d
e 1.50 
PSB Rc68
put
m 1.00 
o
NSIC Rc192
C 0.50 
Sapaw
‐
Aerobic
Flooded
Soil Moisture Regimes

Figure30. Interaction effect between the moisture regimes and the varieties on
computed yield per hectare in Kapangan, Benguet during theAugust
2010-February 2011 season


0.90 
0.80 
a
) 0.70 
/
h
0.60 
 
(t
NSIC Rc9
l
d
e 0.50 
 
yi
PSB Rc14
d
e 0.40 
PSB Rc68
put 0.30 
m
o
NSIC Rc192
0.20 
C
0.10 
Sapaw
‐
Aerobic
Flooded
Soil Moisture Regimes

Figure 31. Interaction effect between the moisture regimes and the varieties on
computed yield per hectare in Kapangan, Benguet during the
March-November 2011 cropping period
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Water use efficiency


Effect of water regimes. There was no significant difference observed
between soil moisture regimes in terms of water use efficiency during both on the
cropping seasons in Kapangan, Benguet (Table 56). Flooded plots obtained a
higher water use efficiency of 0.25g grain/l during the wet season trial.
Conversely, aerobic plots registered a higher water use efficiency.
Effect of variety. While no significant differences on water use efficiency
was observed among the varieties on the August 2010-February 2011 season there
was significant differenceduring the March-November 2011 season (Table 56).
Sapaw recorded the highest water use efficiency on both seasons while
NSIC Rc 192 had the lowest on the August 2010-February 2011 season and PSB
Rc 68 on the March-November 2011cropping season.
Interaction effect. There were no significant interaction during the August
2010-February 2011 season but had a significant interaction between moisture
regimes and the varieties on the water use efficiency during the March-November
2011 growing period (Figure 32). The result showed that Sapaw had the highest
water use efficiency under aerobic and flooded conditions.
 
 
 
 
 
 
 
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Table56. Water use efficiency of rice in Kapangan, Benguet during the August
2010-February 2011 and March-November 2011 cropping periods

TREATMENT
WATER USE EFFICIENCY (g grain/l)

AUG 2010-FEB 2011
MAR-NOV 2011
Soil Moisture Regimes (M)
Aerobic
0.210
0.013
Flooded
0.250
0.010
Varieties (V)
NSIC Rc 9
0.210
0.009b
PSB Rc 14
0.150
0.008b
PSB Rc 68
0.240
0.004b
NSIC Rc 192
0.120
0.010b
Sapaw
0.430 0.027a
M x V
0.78ns 7.06**
CVa (%) 5.43
0.000
CVb (%) 4.37
0.000
For each column, treatment means with different letter are significantly different at 5% probability
levels (DMRT).

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159 
 
0.040 
s
/
l
)
0.035 
a
i
n
0.030 
 
gr
0.025 
NSIC Rc9
c
y
 
(g
0.020 
PSB Rc14
f
i
c
i
en
0.015 
 
ef
PSB Rc68
e 0.010 
r
 
us
NSIC Rc192
t
e 0.005 
Sapaw
Wa
‐
Aerobic
Flooded
Soil Moisture Regimes


Figure 32. Interaction effect between the moisture regimes and the
varietieson water use efficiency in Kapangan, Benguet during the
March-November 2011 growing season



Sensory Evaluation
Aroma. PSB Rc 14, 68 and Sapaw in both soil moisture regimes had
moderate aroma (Table 57). NSIC Rc 9 and 192 had also moderate aroma in
aerobic but had bland and slightly perceptible in flooded, respectively.
Taste. NSIC Rc 9 were rated slightly tasty in both soil moisture regimes.
The rest of the varieties were moderate in taste also in both aerobic and flooded.
Texture. PSB Rc 14 had moderately soft grains and NSIC Rc 192 had
slightly hard grains in both soil moisture regimes. The rest of the varieties were
rated either moderately soft or slightly hard grains in aerobic and flooded.

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160 
 
Table 57. Sensory evaluation of rice varieties in Kapangan, Benguet (2010-2011)

SOIL
GENERAL
MOISTURE
VARIETY AROMA
TASTE
TEXTURE ACCEPTABILITY
REGIMES
NSIC Rc9
Moderate
Like moderately
Slightly tasty
Moderately Soft
PSB Rc14
Moderate
Like slightly
Moderate Moderately
Soft
AEROBIC
PSB Rc68
Moderate
Moderate
Like moderately
Moderately Soft
NSIC Rc192
Moderate
Like moderately
Moderate Slightly
hard
Sapaw Moderate
Like very much
Moderate
Moderately Soft
NSIC Rc9
Bland
Slightly tasty
Like moderately
Slightly hard
PSB Rc14
Moderate
Like moderately
Moderate Moderately
Soft
FLOODED
PSB Rc68
Moderate
Like moderately
Moderate Slightly
hard
NSIC Rc192
Slightly
Like very much
Moderate Slightly
hard
perceptible
Sapaw Moderate
Moderate
Like moderately
Slightly hard


General Acceptability. Sapaw in aerobic plots and NSIC Rc 192 in
flooded fields were liked very much by the testers. Sapaw grown under aerobic
condition had moderate aroma and taste and moderately soft textured grains.
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Correlation Among Growth and Yield Parameters on Rice Grain Yield under
Aerobic Condition in Lagangilang, Abra during the WS 2010 and DS 2011


Among the various growth parameters used, only total dry matter weight
and harvest index had significant correlation with yield (Table 58). Harvest index
had a positive significant correlation with yield. This indicates that grain yield in
aerobic rice increases as harvest index increases. Thisemphasizes the importance
of harvest index enhancement as confirmed by Yang and Zhang (2010), through
improved crop management practices like moderate wetting and drying regime
(aerobic rice) which reduces redundant vegetative growth, increases harvest index
and eventually higher yield.
On the other hand, a negative significant correlation exists between total
dry matter weight and yield. This may imply that for every decrease in unit of
total dry matter weight there is a corresponding increase in grain yield.
Researches on different rice varieties revealed that tall varieties with large canopy
and delayed senescence had decreased grain yield since stored carbohydrates are
concentrated in the vegetative parts and not on grains (Yang and Zhang, 2010).

Correlation Among Growth and Yield Parameters on Rice Grain Yield under
Aerobic Condition in Luna, Apayao during the WS 2010 and DS 2011

The results revealed that panicle length and filled grain number per
panicle had significant positive correlation with grain yield (Table 59). Likewise,

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162

Table 58.Correlation among thegrowth and yield parameters on therice grainyield
under aerobic condition in Lagangilang, Abra during the WS 2010 and
DS 2011

COEFFICIENT
PARAMETERS
OF
PROBABILITY
CORRELATION
Plant Height at Maturity (cm)
-0.132 ns
0.833
Number of Days from Seeding to Maturity
-0.609 ns
0.275
Leaf Area Index at 75 DAS
0.650 ns
0.936
Tiller Number at Maturity
-0.317 ns
0.604
Panicle Number at Maturity
-0.134 ns
0.830
Panicle Length (cm)
-0.340 ns
0.575
Grain Number per Panicle
-0.192 ns
0.757
Number of Filled Grains per Panicle
-0.189 ns
0.760
Filled Grain Ratio (%)
0.631 ns
0.254
1000-Grain Weight (g)
-0.203 ns
0.743
Total Dry Matter Weight (g)
-0.873*
0.043
Harvest Index
0.850*
0.048
Legend: ns (not significant)
* - significant


the total grain number per panicle had significant positive relationship with grain
yield. The positive correlationindicates that when the panicle length, grain number
and number of filled grains per panicle increasethe grain yieldalso

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Table 59. Correlation among thegrowth and yield parameters on the rice
grainyield under aerobic condition in Luna, Apayao during the WS
2010 and DS 2011

COEFFICIENT
PARAMETERS
OF
PROBABILITY
CORRELATION
Plant Height at Maturity (cm)
0.700 ns
0.188
Number of Days from Seeding to Maturity
0.422 ns
0.479
Leaf Area Index at 75 DAS
0.399 ns
0.506
Tiller Number at Maturity
-0.795 ns
0.108
Panicle Number at Maturity
-0.766 ns
0.123
Panicle Length (cm)
0.915*
0.030
Grain Number per Panicle
0.966**
0.008
Number of Filled Grains per Panicle
0.938*
0.018
Filled Grain Ratio (%)
0.349 ns
0.565
1000-Grain Weight (g)
0.285 ns
0.642
Total Dry Matter Weight (g)
0.836 ns
0.078
Harvest Index
0.089 ns
0.886
Legend: ns - not significant
* - significant
** -highly significant



increases. This implies that varieties having long panicle with more filled grains
have high grain yield under aerobic condition in Luna, Apayao.

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The rest of the parameters did not show significant correlation with grain
yield under aerobic condition in Luna, Apayao during the WS 2010 and DS 2011.

Correlation Among Growth and Yield Parameters on Rice Grain Yield under
Aerobic Condition in Kapangan, Benguet during the WS 2010 and DS 2011

Plant height at physiological maturity, number of days from seeding to
maturity, total and filled grain number per panicle and total dry matter weight had
significant positive correlations with grain yield under aerobic condition in
Kapangan, Benguet (Table 60). This indicates that for every unit increase in plant
height at physiological maturity, maturity days, total and filled grain number per
panicle, and total dry matter weight, there is a corresponding increase in grain
yield. This suggests that under aerobic condition,varieties that are late maturing,
tall, with high dry matter, and have long panicle with more filled grains are
adaptable and have high grain yield in Kapangan, Benguet.
The results also reveal that the total tiller number at maturity and panicle
number have negative significant correlation with grain yield. Even if there are
more tillers at maturity per unit area if most are unproductive, then the grain yield
is low. Similarly, even with more panicles at physiological maturity per unit area
but if most have unfilled grains, then it would still result to low grain yield.






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165

Table 60. Correlation among thegrowth and yield parameters on rice grain
yieldunder aerobic condition in Kapangan, Benguet during the WS
2010 and DS 2011

COEFFICIENT
PARAMETERS
OF
PROBABILITY
CORRELATION
Plant Height at Maturity (cm)
0.941*
0.017
Number of Days from Seeding to Maturity
0.934*
0.020
Leaf Area Index at 75 DAS
0.059ns
0.925
Tiller Number at Maturity
-0.924*
0.025
Panicle Number at Maturity
-0.911*
0.032
Panicle Length (cm)
0.970**
0.006
Grain Number per Panicle
0.895*
0.040
Number of Filled Grains per Panicle
0.957*
0.011
Filled Grain Ratio (%)
0.852ns
0.067
1000-Grain Weight (g)
0.817ns
0.091
Total Dry Matter Weight (g)
0.937*
0.019
Harvest Index
0.239ns
0.698
Legend: ns - not significant
* - significant
** - highly significant


Correlation Among Growth and Yield Parameters on Rice Grain Yield under
Flooded Condition in Lagangilang, Abra during the WS 2010 and DS 2011

The correlations among growth and yield parameters with grain yield are
presented in Table 61. No significantcorrelation exist among the growth and
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166


Table 61.Correlation among thegrowth and yield parameters on rice grain
yieldunder flooded condition in Lagangilang, Abra during the WS 2010
and DS 2011

COEFFICIENT
PARAMETERS
OF
PROBABILITY
CORRELATION
Plant Height at Maturity (cm)
-0.602ns
0.283
Number of Days from Seeding to Maturity
-0.738ns
0.155
Leaf Area Index at 75 DAS
-0.235ns
0.704
Tiller Number at Maturity
0.218ns
0.725
Panicle Number at Maturity
0.302ns
0.621
Panicle Length (cm)
-0.049ns
0.937
Grain Number per Panicle
-0.264ns
0.668
Number of Filled Grains per Panicle
-0.483ns
0.410
Filled Grain Ratio (%)
-0.333ns
0.584
1000-Grain Weight (g)
-0.112ns
0.857
Total Dry Matter Weight (g)
-0.663ns
0.222
Harvest Index
0.815ns
0.093
Legend: ns (not significant)


yieldparameters with grain yield under flooded condition in Lagangilang, Abra.
This indicates that said parameters did not influence the grain yield. As the result
implies, grain yield may be affected by the inherent characteristics of the
varieties.
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Correlation Among Growth and Yield Parameters on Rice Grain Yield under
Flooded Condition in Luna, Apayao during the WS 2010 and DS 2011


Correlation amonggrowth and yield parameters with grain yield of rice grown in
aerobic plots in Luna, Apayao is presented in Table 62. The result reveals that
both tiller and panicle number at maturity have negative significant correlation
with grain yield in flooded fields in Luna, Apayao. This implies that more
unproductive tillers, and panicles with more unfilled grains reduce grain yield in
flooded plots in Luna, Apayao. Cultural management practices such as proper
water and nitrogen fertilizer management maybe adopted to maintain few but
productive tillers with more filled grains per panicle.

Correlation Among Growth and Yield Parameters on Rice Grain Yield under
Flooded Condition in Kapangan, Benguet during the WS 2010 and DS 2011

Table 63 presents the correlation among the growth and yield parameters
with grain yield under flooded condition in Kapangan, Benguet. The result reveals
that total dry matter weight and harvest index had significant positive correlations
with grain yield. This indicates that for every unit increase in dry matter and
harvest index the grain yield also increases. With high dry matter and harvest
index, there is also high grain yield.




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Table 62. Correlation among the growth and yield parameters on rice grain
yieldunder flooded condition in Luna, Apayao during the WS 2010 and
DS 2011

COEFFICIENT
PARAMETERS
OF
PROBABILITY
CORRELATION
Plant Height at Maturity (cm)
0.466ns
0.429
Number of Days from Seeding to Maturity
0.322ns
0.597
Leaf Area Index at 75 DAS
0.134ns
0.830
Tiller Number at Maturity
-0.912*
0.031
Panicle Number at Maturity
-0.896*
0.040
Panicle Length (cm)
0.869ns
0.056
Grain Number per Panicle
0.853ns
0.066
Number of Filled Grains per Panicle
0.777ns
0.122
Filled Grain Ratio (%)
-0.411ns
0.492
1000-Grain Weight (g)
0.384ns
0.524
Total Dry Matter Weight (g)
0.547ns
0.340
Harvest Index
0.094ns
0.881
Legend: ns - not significant
* - significant
** - highly significant







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169

Table 63.Correlation among thegrowth and yield parameters on rice grain yield
under flooded condition in Kapangan, Benguet during the August 2010-
February 2011 and March-November 2011 cropping periods

COEFFICIENT
PARAMETERS
OF
PROBABILITY
CORRELATION
Plant Height at Maturity (cm)
0.748ns
0.146
Number of Days from Seeding to Maturity
0.848ns
0.069
Leaf Area Index at 75 DAS
0.813ns
0.095
Tiller Number at Maturity
-0.713ns
0.161
Panicle Number at Maturity
-0.653ns
0.232
Panicle Length (cm)
0.674ns
0.212
Grain Number per Panicle
0.047ns
0.941
Number of Filled Grains per Panicle
0.574ns
0.312
Filled Grain Ratio (%)
0.769ns
0.128
1000-Grain Weight (g)
0.814ns
0.093
Total Dry Matter Weight (g)
0.960**
0.010
Harvest Index
0.966**
0.008
Legend: ns - not significant
* - significant
** - highly significant








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Comparison of Plant Height and Maturity of Rice Varieties under Two Moisture
Regimes in Different Sites


Characters which significantly differed among the different varieties were
considered. In terms of plant height and maturity days under both aerobic and
flooded conditions, all varieties were short but late maturing in Kapangan,
Benguet; and tall but early maturing in Luna, Apayao. Varieties grown in
Lagangilang, Abra were similar with those in Luna, Apayao in terms of plant
height and maturity (Table 64).
The variation in plant height and maturity period among varieties maybe
influenced by environmental factors like rainfall and relative humidity. In Luna,
Apayao, 3,380.60 mm rainfall was recorded during the two cropping seasons
which was the highest among the three sites. Further, it is situated at about 5 m asl
as compared to 1,000 m asl in Kapangan, Benguet site.

Comparison of Yield and Yield Components of Rice Varieties Across Sites


PSB Rc14 had a mean of 102.50 and 113 panicles in Lagangilang, Abra;
25.13 and 114.88 panicles in Luna, Apayao under aerobic and flooded conditions,
respectively (Table 65). In Kapangan, Benguet, NSIC Rc192 had a mean of 44.63
panicles under aerobic and 46.64 panicles from PSC Rc68 under flooded fields.

NSIC Rc9 had 133.46 and 138.33 mean filled grains per panicle in
Lagangilang, Abra; 140.88 and 136.14 mean filled grains per panicle in Luna,

Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
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171

Table 64.Comparison of plant height and maturity days of rice varieties
grownacross sites during the WS 2010 and DS 2011

PARA-
AEROBIC
FLOODED
VARIETY
METER
APA-
BEN-
APA-
BEN-
ABRA
YAO
GUET MEAN ABRA
YAO
GUET
MEAN





NSIC Rc9
101.41
115.44
80.58
99.14 112.48 127.08 88.94
109.50







Plant
PSB Rc14
75.59
78.69
59.16
71.15
84.26
85.09
68.64
79.33
Height







(cm)
PSB Rc68
102.39
113.00 74.55
96.65
113.62
123.41 89.68
108.90







NSIC Rc192 101.06
107.69 63.88
90.88
106.41
121.15 77.11
101.56







NSIC Rc9
116.50
99.00
161.75 125.75 113.50 99.00
155.13 122.54







Maturity
PSB Rc14
101.00
94.00
151.50 115.50 101.00 93.00
142.50 112.17
Days







(No.)
PSB Rc68
110.00
112.00 174.00 132.00 111.50 110.00 161.50 127.67







NSIC Rc192 99.50
93.00
148.00 113.50 98.50 92.00
139.50 110.00



Apayao; and 93.38 and 86.75 filled grains per panicle in Kapangan, Benguet,
respectively.
As to 1000-grain weight, PSB Rc68 had 28.20 g and 29.59 g in
Lagangilang, Abra; 29.98 g and 30.48 g in Luna, Apayao; and 24.04 g and 24.84
g in Kapangan, Benguet under aerobic and flooded condition, respectively.

In terms of grain yield per 5.75 m2 under aerobic and flooded condition,
NSIC Rc192 weighed 3.10 kg and NSIC Rc136H at 4.09 kg in Lagangilang,
Abra; NSIC Rc9 weighed 2.92 kg and NSIC Rc136H at 3.33 kg in Luna, Apayao;
and NSIC Rc9 with 0.41 kg and PSB Rc68 with 0.94 kg in Kapangan, Benguet,
respectively.

Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
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172

Table 65.Comparison of yield and yield components of rice varieties across
sites,WS 2010 and DS 2011

PARA-
AEROBIC
FLOODED
VARIETY
METER
APA-
BEN-
APA-
BEN-
ABRA
YAO
GUET
MEAN
ABRA
YAO
GUET
MEAN

Panicle
NSIC Rc9
2.92
22.74
19.73
15.13 24.38 23.23 19.43 22.35
Length
PSB Rc14
1.55
20.29
17.34
13.06 21.14 20.57 17.97 19.89
(cm)
PSB Rc68
2.39
22.61
17.87
14.29 24.42 24.20 18.22 22.28
NSIC Rc192
1.99
20.55
15.73
12.76 22.56 21.03 17.43 20.34
NSIC Rc9
133.46 140.88
93.38
122.57 138.33 136.14 86.75 120.41
No. of
PSB Rc14
73.63
74.63
65.38
71.21 79.59 72.86 59.00 70.48
Filled
PSB Rc68
116.28 102.00
70.25
96.18 129.58 120.35 69.25 106.39
Grains
NSIC Rc192
112.24
94.75
59.63
88.87 113.34 111.61 73.75 99.57
NSIC Rc9
22.48
23.94
20.17
22.20 22.99 23.79 19.51 22.10
1000-
PSB Rc14
22.91
23.29
18.12
21.44 23.23 23.38 19.97 22.19
Grain
PSB Rc68
28.20
29.98
24.04
27.41 29.59 30.48 24.84 28.30
Weight (g)
NSIC Rc192
24.83
24.19
20.23
23.08 26.77 23.95 19.38 23.37
NSIC Rc9
2.53
2.92
0.41
1.95 3.44 3.21 0.83 2.49
Grain
PSB Rc14
2.50
1.55
0.31
1.45 3.50 2.06 0.59 2.05
Yield (kg
PSB Rc68
2.16
2.39
0.38
1.64 3.20 3.00 0.94 2.38
5.75m2-1)
NSIC Rc192
3.10
1.99
0.27
1.79 3.62 2.48 0.49 2.20



Comparison of Mean Computed Yield Across Sites


Under aerobic condition the mean computed yield per site from the earlier
results are as follows: 5.38 t/ha from NSIC Rc192 in Lagangilang, Abra; 5.07 t/ha
from NSIC Rc 9 in Luna, Apayao; and 0.71 t/ha also from NSIC Rc9 in
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173

Kapangan, Benguet. In flooded fields, NSIC Rc136H in Lagangilang, Abra had
7.11 t/ha; NSIC Rc136H in Luna, Apayao produced 5.79 t/ha; and PSB Rc68 in
Kapangan, Benguet produced 1.64 t/ha (Table 66).

Comparison of Difference on Computed Yield of Rice Varieties between Aerobic
and Flooded Condition


Table 67 shows the varieties which had low mean computed yield
difference between aerobic and flooded plots. In Lagangilang, Abra, NSIC Rc192
was 15% (0.92 t/ha) lower on computed yield in aerobic than in flooded fields;
9% (0.51 t/ha) lower on computed yield from NSIC Rc9 in Luna, Apayao; and
46% (0.40 t/ha) lower from NSIC Rc192 in Kapangan, Benguet.


Table 66. Computed yield (t ha-1) of rice in three sites during the WS 2010 and
DS 2011


AEROBIC FLOODED
VARIETY
ABRA APA-
BEN-
MEAN ABRA APA-
BEN-
MEAN
YAO
GUET
YAO
GUET
NSIC
Rc9 4.41 5.07 0.71 3.40 5.98 5.58 1.44 4.33
PSB
Rc14 4.34 2.70 0.54 2.52 6.09 3.58 1.03 3.57
NSIC
Rc68 3.76 4.16 0.67 2.86 5.56 5.22 1.64 4.14
NSIC
Rc192
5.38 3.46 0.46 3.10 6.30 4.31 0.86 3.82








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Table 67. Yield difference between aerobic and flooded fields, WS 2010 and DS
2011

PARA‐
ABRA
APAYAO
BENGUET 
MEAN
VARIETY 
METER 
VALUE
%
VALUE
%
VALUE
% 
VALUE 
%
Compu
NSIC Rc 9 
(1.57)
(26)
(0.51)
(36)
(0.73)
(51) 
(0.94) 
(38)
ted 
PSB Rc 14 
(1.75)
(29)
(0.89)
(86)
(0.50)
(48) 
(1.04) 
(54)
Yield 
PSB Rc 68 
(1.80)
(32)
(1.07)
(65)
(0.97)
(59) 
(1.28) 
(52)
(t/ha) 
NSIC Rc 192 
(0.92)
(15)
(0.85)
(99)
(0.40)
(46) 
(0.72) 
(53)

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175 
 
SUMMARY, CONCLUSIONS AND RECOMMENDATION
 

Summary

The study was conducted to compare the growth performance and grain
yield of different rice varieties under two moisture regimes in different agro-
ecological zones; to determine total water use efficiency of different rice varieties
under two moisture regimes in different agro-ecological zones; identify the best
variety under two moisture regimes in different agro-ecological zones; and
evaluate the performance of rice varieties grown organically under two moisture
regimes in a mid mountain zone of Benguet.There were sites namely:
Lagangilang, Abra; Luna, Apayao; andKapangan, Benguet. The field experiment
was conducted in two cropping seasons: July-November 2010 in Lagangilang,
Abra and Luna, Apayao; and August 2010-February 2011 in Kapangan, Benguet;
and December 2010-April 2011 in Lagangilang, Abra and Luna, Apayao; and
March-November 2011 in Kapangan, Benguet.

Moisture Regimes
In all three sites and during both cropping seasons, significant differences
were observed between the two moisture regimes on plant height at maturity, total
dry matter weight and grain yield. The rest of the parameters showed varied
results as influenced by the moisture regimes.
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In Lagangilang, Abra, varieties grown under flooded condition were taller,
matured earlier, had more panicles and higher grain yieldas well as computed
yield per hectare in both seasons. Likewise, longer panicles, more filled and total
grains per panicle, dry matter weight, and harvest index during the dry season
inthe same moisture regimewere noted. On the other hand, plants in aerobic plots
had more grains per panicle during the wet season only.

In Luna, Apayao, plants grown under flooded condition were taller,
produced longer panicles, hadhigher filled grain ratio, dry matter weight, grain
and computed yield, and higher water use efficiency than the aerobic plots during
the wet season. During the dry season, more total and filled grains per panicle,
and higher harvest index were observed in flooded than in the aerobic fields.
Higher water use efficiency was noted under the aerobic than the flooded
condition during the dry season.

In Kapangan, Benguet, the plants in flooded fields were taller, had a
higher leaf area index at 75 days after seeding, and higher dry matter weight than
in aerobic plots both during the wet and dry seasons. More panicles, higher dry
matter weight, and higher grain yield were also noted in plants under flooded than
aerobic plots during the wet season cropping. On the other hand, plants under
aerobic plots had higher filled grain ratio and higher harvest index than in flooded
fields during the dry season.
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177 
 
The water use efficiency between the two moisture regimes in the three
sites during the two cropping seasons varied. In Lagangilang, Abra, varieties
grown under aerobic condition had lower water use efficiency than in the flooded
at 0.4 g/l (6%) and 0.62 g/l (43%) during the wet and dry season, respectively. In
Luna, Apayao, water use efficiency in aerobic was 0.06 g/l (26%) lower but was
also 0.06 g/l (43%) higher than the flooded during the WS and DS, respectively.
In Kapangan, Benguet, water use efficiency was lower by 0.04 g/l (16%) and
higher by 0.003 g/l (30%) in aerobic than in flooded fields.
 
Varieties

Among the rice varieties, highly significant differences were noted in all
three sitesand during the wet and dry cropping seasonsin terms of plant height at
maturity, panicle length, grain number per panicle, number of filled grains, 1000-
grain weight, total dry matter weight, harvest index, and grain yield.
In Lagangilang, Abra during the wet season, NSIC Rc136H had highest
grain yield, harvest index and water use efficiency. NSIC Rc192 was comparable
with NSIC Rc136H in terms of grain yield and harvest index; both varieties had
the highest LAI at 75 days after seeding and filled grain ratio; and matured
earliest. On the other hand, PSB Rc14 attained the lowest grain yield, lowest leaf
area index at 75 days after seeding, shortest panicle length, least filled and total
number grains per panicle, and lowest water use efficiency.
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178 
 
For dry season in Lagangilang, Abra, NSIC Rc136H had the highest grain
yield, matured earliest, and had the highest harvest index. NSIC Rc136H and
NSIC Rc192were comparable as these varieties produced the highest grain yield,
exhibited the highest LAI at 75 DAS, had the most grain number per panicle and
highest harvest index. In contrast, PSB Rc14 again produced the lowest grain
yield, shortest plants at maturity, lowest leaf area index at 75 days after seeding,
shortest panicle with the least filled and total number of grains per panicle.
In Luna, Apayao during the wet season, NSIC Rc9 had attained the
highest grain yield with tallest plants, most panicle at maturity, longest panicle,
most filled and total number of grains per panicle, highest dry matterand water
use efficiency. NSIC Rc192 was comparable with NSIC Rc9 in terms of grain
yield. NSIC Rc192 matured the earliest, had the highest leaf area index, filled
grain ratio, and harvest index. Further, NSIC Rc136H was comparable with NSIC
Rc9 in terms of grain yield. Both varieties are early maturing, had long panicles
and had high harvest index and high water use efficiency.
During the dry season, PSB Rc68 produced the highest grain yield; highest
and longest panicles, the highest 1000-grain weight, dry matter weight, and water
use efficiency. Conversely, PSB Rc14 had the lowest grain yield with the shortest
plants at maturity, lowest LAI at 75 DAS, shortest panicle with the least filled
grains per panicle, lowest 1000-grain weight, dry matter weight, harvest index and
WUE.
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In Kapangan, Benguet during the August 2010-February 2011, PSB Rc68
produced the highest grain yield, highest 1000-grain weight, dry matter weight,
and harvest index. NSIC Rc9 was comparable with PSB Rc68 in terms of grain
yield and harvest index. Sapawwas found comparable with PSB Rc68 on grain
yield. Sapawhad the tallest plants and matured the latest; had the longest with
more grains per panicle; produced the highest 1000-grain weight and had the
highest harvest index. The lowest yielder for the same growing period was NSIC
Rc192.It matured the earliest, had the shortest with the least grains per panicle,
and lowest 1000-grain and dry matter weight.
For March-November 2011 cropping season, Sapawproduced the highest
yield with the longest panicles having the highest grains per panicle; had highest
1000-grain weight, dry matter weight, harvest index and water use efficiency.
 
Moisture Regime and Variety Interaction
No significant interaction between the moisture regimes and the rice
varieties on leaf area index, panicle number at maturity, panicle length, grain
number per panicle, and harvest index in all three sites and in both the wet and
dry seasons were noted.

In Lagangilang, Abra, plant height at maturity and filled grain ratio both
during the dry season had significant interaction effect.

In Luna, Apayao, a significant interaction exist between the moisture
regimes and the rice varieties on plant height and filled grain ratio during the wet
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180 
 
season. Likewise, a significant interaction effect was observed on water use
efficiency during the dry season.

InKapangan, Benguet, a significant interaction was registered between the
moisture regimes and the rice varieties in terms of grain yield and number of
filled grains per panicle for both cropping seasons; also on dry matter weight
during the August 2010-February 2011 cropping season; and on filled grain ratio,
1000-grain weight, and water use efficiency during the March-November 2011
cropping period.
 
Correlation Between Growth and Yield Parameters

Under aerobic condition, a significant positive correlationon harvest index
with grain yield was noted in Lagangilang, Abra. The panicle length, total and
filled grain number per panicle with grain yield was likewise notedin Luna,
Apayao. The plant height at maturity, number of days from seeding to maturity,
panicle length, total and filled grain per panicle, and total dry matter weight were
likewise observed to have a significant positive correlation with grain yield in
Kapangan, Benguet under the same soil moisture regime. A significant negative
correlation existed between total dry matter weight with grain yield in
Lagangilang, Abra; and on the total tiller and panicle number at maturity with
grain yield in Kapangan, Benguet.

Under flooded condition, a significantpositive correlation occurred
between the total dry matter weight and harvest index with grain yield in
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes 
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181 
 
Kapangan, Benguet and a significant negative correlation between total tiller and
panicle number at maturity with grain yield in Luna, Apayao.

Conclusions

Based on the results of the study, the following conclusions are drawn:
1. NSIC Rc192 and NSIC Rc 136H produces the highest grain yield and
water use efficiency in Lagangilang, Abra.under aerobic and flooded
conditions, respectively.
2. NSIC Rc9 and NSIC Rc136H have the highest grain yield and water use
efficiencyin Luna, Apayaounder aerobic and flooded condition,
respectively.
3. Sapawhas the highest grain yield and water use efficiency both under
aerobic and flooded conditions in Kapangan, Benguet.
4. Water use efficiency is highest in Lagangilang, Abra; Luna, Apayao; and
Kapangan, Benguet under aerobic condition with NSIC Rc192, NSIC Rc9,
and Sapaw; in flooded fields: NSIC Rc136H and Sapaw, respectively.
5. Sapaw, PSB Rc68 and NSIC Rc9 have high grain yield under organic
production in Kapangan, Benguet during the August-February cropping
period.
6. Under aerobic condition, significant positive correlation on harvest index
with grain yield exist in Lagangilang, Abra; panicle length, total and filled
grain number per panicle with grain yield in Luna, Apayao; plant height at
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maturity, number of days from seeding to maturity, panicle length, total
and filled grain per panicle, and total dry matter weight with grain yield in
Kapangan, Benguet.
7. Significant negative correlation exist between total dry matter weight with
grain yield in Lagangilang, Abra; and on the total tiller and panicle
number at maturity with grain yield in Kapangan, Benguet under aerobic
condition.
8. Significant positive correlation happen between the total dry matter weight
and harvest index with grain yield in Kapangan, Benguet and a significant
negative correlation between total tiller and panicle number at maturity
with grain yield in Luna, Apayao under flooded condition.
 
Recommendations

Considering the findings in the study, the following are recommended:
1. NSIC Rc192 and NSIC Rc9 can be grown under aerobic condition
regardless of cropping season in Lagangilang, Abra and Luna, Apayao.
2. NSIC Rc136H can be grown under flooded condition both inLagangilang,
Abra and Luna, Apayao.
3. Sapawcan alsobe grown under both aerobic and flooded conditions in
Kapangan, Benguet.
4. Sapaw, PSB Rc68 and NSIC Rc9 can be grown organically in Kapangan,
Benguet. Yield levels of these varieties can still be improved with the
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183 
 
application of soil amendments following the organic production
approach.
5. Characters significantly correlated with yield can be used as selection
indices for rice varieties grown under aerobic and flooded conditions.
6. Further studies for other rice varieties or lines on drought and in other
locations in the region experiencing the same water limiting condition
during the dry season.


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Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

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189

APPENDICES

APPENDIX TABLE 1. Analysis of variance for plant height at maturity (cm)
(Abra, WS 2010)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 65.67
21.89
5.17ns


Moisture
1 75.63
75.63
17.87**
10.13
34.14
Regimes
Error (a)
3
12.68
4.23



Variety 4
6,932.35
1,733.09 56.25**
2.78
4.22
MR x V
4
82.25
20.56
0.67ns 2.78
4.22
Error (b)
24
739.40
30.81


TOTAL 39
7,907.97




ns-not significant



CV (a) = 1.76%
**-highly
significant CV
(b)
=
4.76%

APPENDIX TABLE 2. Analysis of variance for plant height at maturity (cm)
(Abra, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 9.67
3.22
4.35ns


Moisture
1 2,050.62
2,050.62
2,771.11** 10.13 34.14
Regimes
Error (a)
3
2.22
0.74



Variety 4
4,155.20
1,038.80 97.90**
2.78
4.22
MR x V
4
135.37
33.84
3.19*
2.78
4.22
Error (b)
24
254.66
10.61


TOTAL 39
6,607.74




ns-not significant


CV (a) = 1.11%
**-highly
significant CV
(b)
=
4.20%
*- significant

APPENDIX TABLE 3. Analysis of variance for number of days from seeding to
maximum tillering (Abra, WS 2010)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 4.08
1.36
8.58ns


Moisture
1 0.23
0.23
1.42ns 10.13
34.14
Regimes
Error (a)
3
0.48
0.16



Variety 4
42.65
10.66
14.46**
2.78
4.22
MR x V
4
3.65
0.91
1.24ns
2.78 4.22
Error (b)
24
17.70
0.74


TOTAL 39
68.78




ns- not significant



CV (a) = 1.17%
**-
highly
significant
CV
(b)
=
2.50%
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

190

APPENDIX TABLE 4. Analysis of variance for number of days from seeding to
maximum tillering (Abra, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 2.08
0.69
2.36ns


Moisture
1 93.03
93.03
318.57**
10.13
34.14
Regimes
Error (a)
3
0.88
0.29



Variety 4
15.85
3.96
4.46**
2.78
4.22
MR x V
4
26.85
6.71
7.56**
2.78
4.22
Error (b)
24
21.30
0.89


TOTAL 39
159.98




ns- not significant



CV (a) = 2.30%
**-
highly
significant
CV
(b)
=
1.33%

APPENDIX TABLE 5. Analysis of variance for number of days from maximum
tillering to booting (Abra, WS 2010)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 5.08
1.69
5.79ns


Moisture
1 0.63
0.63
2.14ns
10.13 34.14
Regimes
Error (a)
3
0.88
0.29



Variety 4
58.60
14.65
12.21**
2.78
4.22
MR x V
4
13.00
3.25
2.71ns
2.78 4.22
Error (b)
24
28.80
1.20


TOTAL 39
106.98




ns- not significant



CV (a) = 1.88%
**-
highly
significant
CV
(b)
=
3.80%

APPENDIX TABLE 6. Analysis of variance for number of days from maximum
tillering to booting (Abra, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 0.50
0.17
0.84ns


Moisture
1 1.60
1.60
8.00ns
10.13 34.14
Regimes
Error (a)
3
0.60
0.20



Variety 4
309.85
77.46
170.56**
2.78
4.22
MR x V
4
3.65
0.91
2.01ns
2.78 4.22
Error (b)
24
10.90
0.45


TOTAL 39
327.10




ns- not significant



CV (a) = 1.44%
**-
highly
significant
CV
(b)
=
2.20%



Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

191


APPENDIX TABLE 7. Analysis of variance for number of days from booting to
heading (Abra, WS 2010)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 1.70
0.57
17.18*


Moisture
1 0.10
0.10
3.03ns
10.13 34.14
Regimes
Error (a)
3
0.10
0.03



Variety 4
112.35
28.09
100.61**
2.78
4.22
MR x V
4
0.15
0.04
0.14ns
2.78 4.22
Error (b)
24
6.70
0.28


TOTAL 39
121.10




ns- not significant



CV (a) = 2.10%
**-
highly
significant
CV
(b)
=
6.10%
*- significant

APPENDIX TABLE 8. Analysis of variance for number of days from booting to
heading (Abra, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 1.48
0.49
1.37ns


Moisture
1 0.63
0.63
1.74ns 10.13
34.14
Regimes
Error (a)
3
1.08
0.36



Variety 4
106.85
26.71
112.47**
2.78
4.22
MR x V
4
0.25
0.06
0.27ns 2.78
4.22
Error (b)
24
5.70
0.24


TOTAL 39
115.98




ns- not significant



CV (a) = 7.01%
**-
highly
significant
CV
(b)
=
5.70%

APPENDIX TABLE 9. Analysis of variance for number of days from heading to
maturity (Abra, WS 2010)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 2.60
0.87



Moisture
1 0.40
0.40
1.20ns 10.13
34.14
Regimes
Error (a)
3
1.00
0.33
620.03**


Variety 4
1,281.40
320.35
2.23ns 2.78
4.22
MR x V
4
4.60
1.15

2.78
4.22
Error (b)
24
12.40
0.52


TOTAL 39
1,302.40




ns- not significant



CV (a) = 1.82%
**-
highly
significant
CV
(b)
=
2.27%

Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

192

APPENDIX TABLE 10. Analysis of variance for number of days from heading to
maturity (Abra, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 8.50
2.83



Moisture
1 0.90
0.90
0.39ns
10.13 34.14
Regimes
Error (a)
3
6.90
2.30
126.00**


Variety 4
1,629.65
407.41
8.22**
2.78
4.22
MR x V
4
106.35
26.59

2.78
4.22
Error (b)
24
77.60
3.23


TOTAL 39
1,829.90




ns- not significant



CV (a) = 5.71%
**-
highly
significant
CV
(b)
=
6.77%


APPENDIX TABLE 11. Analysis of variance for leaf area index at 75 DAS
(Abra, WS 2010)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
0.0203
0.0068
0.29ns


Moisture
1 0.0006
0.0006
0.03ns 10.13
34.14
Regimes
Error (a)
3
0.0706
0.0236



Variety 4
0.3034
0.0758
4.15*
2.78
4.22
MR x V
4
0.0163
0.0041
0.22ns 2.78
4.22
Error (b)
24
0.4390
0.0183


TOTAL 39
0.8503




ns- not significant



CV (a) = 6.02%
*- significant








CV (b) =
5.30%

Appendix Table 12. Analysis of variance for leaf area index at 75 DAS (Abra, DS
2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
0.1018
0.0339
0.85ns


Moisture
1 1.1170
1.1170
27.92*
10.13
34.14
Regimes
Error (a)
3
0.1199
0.0400
2.92*


Variety 4
0.3319
0.0830
2.36ns 2.78
4.22
MR x V
4
0.2681
0.0670

2.78
4.22
Error (b)
24
0.6812
0.0284


TOTAL 39
2.6198




ns- not significant



CV (a) = 5.85%
*-

significant
CV
(b)
=
4.93%


Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

193


APPENDIX TABLE 13. Analysis of variance for panicle number at maturity
(Abra, WS 2010)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 81.0
27.0
0.26ns


Moisture
1 4,536.9
4,536.9
43.83**
10.13
34.14
Regimes
Error (a)
3
310.5
103.5



Variety 4
9,807.0
2,451.8 13.04**
2.78
4.22
MR x V
4
561.6
140.4
1.38ns 2.78
4.22
Error (b)
24
4,513.0
188.0


TOTAL 39
19,810.0




ns- not significant



CV (a) = 3.58%
**-
highly
significant
CV
(b)
=
3.46%

APPENDIX TABLE 14. Analysis of variance for panicle number at maturity
(Abra, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 306.9
102.3
0.40ns


Moisture
1 1,550.0
1,550.0
6.06ns 10.13
34.14
Regimes
Error (a)
3
767.7
255.9



Variety 4
10,508.6
2,627.2 13.14**
2.78
4.22
MR x V
4
433.1
108.3
1.62ns 2.78
4.22
Error (b)
24
4,796.7
199.9


TOTAL 39
18,363.0




ns- not significant



CV (a) = 4.92%
**-
highly
significant
CV
(b)
=
3.09%

APPENDIX TABLE 15. Analysis of variance for panicle length (cm) (Abra, WS
2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 0.90
0.30
0.24


Moisture
1 0.24
0.24
0.19ns 10.13
34.14
Regimes
Error (a)
3
3.72
1.24



Variety 4
60.51
15.13
26.03**
2.78
4.22
MR x V
4
5.57
1.39
2.40ns 2.78
4.22
Error (b)
24
13.95
0.58


TOTAL
39 84.88



ns- not significant



CV (a) = 4.50%
**-
highly
significant
CV
(b)
=
3.08%


Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

194



APPENDIX TABLE 16. Analysis of variance for panicle length (cm) (Abra, DS
2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication
3 0.97 0.32 0.21

Moisture
1 43.83
43.83
28.33*
10.13
34.14
Regimes
Error (a)
3
4.64
1.55



Variety 4
53.96
13.49
25.85**
2.78
4.22
MR x V
4
3.95
0.99
1.89ns 2.78
4.22
Error (b)
24
12.52
0.52


TOTAL 39
119.88



ns- not significant



CV (a) = 6.00%
**-
highly
significant
CV
(b)
=
3.49%
*- significant

APPENDIX TABLE 17. Analysis of variance for total grain number per panicle
(Abra, WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
590.48
196.83
1.13


Moisture
1 540.23
540.23
3.10ns 10.13
34.14
Regimes
Error (a)
3
523.28
174.43



Variety 4
32,366.65
8,091.66 54.91**
2.78
4.22
MR x V
4
1,031.65
257.91
1.75ns 2.78
4.22
Error (b)
24
3,536.50
147.35


TOTAL 39
38,588.78




ns- not significant



CV (a) = 9.11%
**-
highly
significant
CV
(b)
=
8.35%

APPENDIX TABLE 18. Analysis of variance for total grain number per panicle
(Abra, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
145.63
48.54
1.07


Moisture
1 567.01
567.01
12.47*
10.13
34.14
Regimes
Error (a)
3
136.45
45.48



Variety 4
8,550.83
2,137.71 21.33**
2.78
4.22
MR x V
4
237.14
59.28
1.47ns 2.78
4.22
Error (b)
24
2,405.02
100.21


TOTAL 39
12,042.06




ns- not significant



CV (a) = 0.00%
**-
highly
significant
CV
(b)
=
3.65%
*- significant

Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

195


APPENDIX TABLE 19. Analysis of variance for number of filled grains per
panicle (Abra, WS 2010)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
558.67
186.22
1.04


Moisture
1 525.63
525.63
2.94ns 10.13
34.14
Regimes
Error (a)
3
535.48
178.49



Variety 4
32,041.15
8,010.29 53.58** 2.78
4.22
MR x V
4
990.75
247.68
1.66ns 2.78
4.22
Error (b)
24
3,588.10
149.50


TOTAL 39
38,239.78




ns- not significant



CV (a) = 9.18%
**-
highly
significant
CV
(b)
=
8.42


APPENDIX TABLE 20. Analysis of variance for number of filled grains per
panicle (Abra, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 76.69
25.56
1.17


Moisture
1 4,698.06
4,698.05
214.83**
10.13
34.14
Regimes
Error (a)
3
65.61
21.87



Variety 4
8,550.95
2,137.74 21.22**
2.78
4.22
MR x V
4
655.92
163.98
1.63ns 2.78
4.22
Error (b)
24
2,417.49
100.73


TOTAL 39
16,464.72




ns- not significant



CV (a) = 4.62%
**-
highly
significant
CV
(b)
=
3.09%

APPENDIX TABLE 21. Analysis of variance for filled grain ratio (Abra, WS
2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 7.88
2.63
0.22


Moisture
1 99.23
99.23
8.34ns 10.13
34.14
Regimes
Error (a)
3
35.68
11.89



Variety 4
1,492.15
373.04 27.53**
2.78
4.22
MR x V
4
80.65
20.16
1.49ns 2.78
4.22
Error (b)
24
325.20
13.55


TOTAL 39
2,040.78




ns- not significant



CV (a) = 4.36%
**-
highly
significant
CV
(b)
=
4.66%



Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

196


APPENDIX TABLE 22. Analysis of variance for filled grain ratio (Abra,DS
2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 19.05
6.35
0.26ns


Moisture
1 8.49
8.49
0.35ns 10.13
34.14
Regimes
Error (a)
3
73.53
24.51



Variety 4
231.40
57.85
3.53*
2.78
4.22
MR x V
4
200.39
50.10
3.06*
2.78
4.22
Error (b)
24
393.45
16.39


TOTAL 39
926.31




ns- not significant



CV (a) = 6.44%
*-
significant
CV
(b)
=
5.27%

APPENDIX TABLE 23. Analysis of variance for weight of 1000 filled grains
(Abra, WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 0.34
0.11
0.93ns


Moisture
1 0.55
0.55
4.57ns 10.13
34.14
Regimes
Error (a)
3
0.36
0.12



Variety 4
210.64
52.66
48.68**
2.78
4.22
MR x V
4
5.24
1.31
1.21ns 2.78
4.22
Error (b)
24
25.96
1.08


TOTAL 39
243.09




ns- not significant



CV (a) = 1.30%
**-
highly
significant
CV
(b)
=
3.89%


APPENDIX TABLE 24. Analysis of variance for weight of 1000 filled grains
(Abra, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 0.55
0.18
0.09ns


Moisture
1 20.15
20.15
9.81ns 10.13
34.14
Regimes
Error (a)
3
6.16
2.05



Variety 4
220.43
55.11
93.66**
2.78
4.22
MR x V
4
3.72
0.93
1.58ns 2.78
4.22
Error (b)
24
14.12
0.59


TOTAL 39
265.13




ns- not significant



CV (a) = 6.07%
**-
highly
significant
CV
(b)
=
3.25%




Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

197

APPENDIX TABLE 25. Analysis of variance for total dry matter weight (Abra,
WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
8,535.92
2,845.31
0.86ns


Moisture
1 1.05
1.05
0.0003ns 10.13
34.14
Regimes
Error (a)
3
9,884.46
3,294.82



Variety 4
179,913.16
44,978.29 24.04** 2.78
4.22
MR x V
4
3,086.50
771.63
0.41ns 2.78
4.22
Error (b)
24
44,897.88
1,870.75


TOTAL 39
246,318.97




ns- not significant



CV (a) = 0.13%
**-
highly
significant
CV
(b)
=
2.83%

APPENDIX TABLE 26. Analysis of variance for total dry matter weight (Abra,
DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
1,537.37
512.46
1.22ns


Moisture
1 50,872.56
50,872.56
121.47**
10.13
34.14
Regimes
Error (a)
3
1,256.42
418.806



Variety 4
13,049.81
3,262.45 6.90** 2.78
4.22
MR x V
4
3,962.79
990.70
2.09ns 2.78
4.22
Error (b)
24
11,352.40
473.02


TOTAL 39
82,031.34




ns- not significant



CV (a) = 1.88%
**-
highly
significant
CV
(b)
=
4.01%

APPENDIX TABLE 27. Analysis of variance for Analysis of variance for harvest
index (Abra, WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 79.93
26.65
2.51ns


Moisture
1 12.10
12.10
1.14ns 10.13
34.14
Regimes
Error (a)
3
31.84
10.61



Variety 4
831.48
207.87
15.17**
2.78
4.22
MR x V
4
20.09
5.02
0.37ns 2.78
4.22
Error (b)
24
328.81
13.70


TOTAL 39
1,304.26




ns- not significant



CV (a) = 6.38%
**-
highly
significant
CV
(b)
=
7.25%






Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

198

APPENDIX TABLE 28. Analysis of variance for harvest index (Abra, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 41.38
13.80
4.25ns


Moisture
1 703.08
703.08
216.79**
10.13
34.14
Regimes
Error (a)
3
9.73
3.24



Variety 4
2,896.81
724.20 100.15**
2.78
4.22
MR x V
4
33.12
8.28
1.15ns 2.78
4.22
Error (b)
24
173.54
7.23


TOTAL 39
3,857.67




ns- not significant



CV (a) = 3.99%
**-
highly
significant
CV
(b)
=
5.95%

APPENDIX TABLE 29. Analysis of variance for grain yield (kg) (Abra, WS
2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
144,436.35
48,145.45
1.48ns


Moisture
1 565,535.95
565,535.95
17.44*
10.13
34.14
Regimes
Error (a)
3
97,287.15
32,429.05



Variety 4
6,568,775.27
1,642,193.82 3.93* 2.78
4.22
MR x V
4
1,236,642.52
309,160.63
0.74ns 2.78
4.22
Error (b)
24
10,028,191.45
417,841.31


TOTAL 39
18,640,868.68




ns- not significant



CV (a) = 0.89%
*-
significant
CV
(b)
=
2.13%

APPENDIX TABLE 30. Analysis of variance for grain yield (kg) (Abra, DS
2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
129,453.77
43,151.26
0.99ns


Moisture
1 25,392,726.92
25,392,726.92
584.84**
10.13 34.14
Regimes
Error (a)
3
130,254.35
43,418.12



Variety 4
3,407,562.00
851,890.70 7.77** 2.78
4.22
MR x V
4
181,731.37
45,432.84
0.41ns 2.78
4.22
Error (b)
24
2,630,630.97
109,609.62


TOTAL 39
31,872,360.16




ns- not significant



CV (a) = 7.86%
**-
highly
significant
CV
(b)
=
12.48%






Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

199

APPENDIX TABLE 31. Analysis of variance for computed yield (t ha-1) (Abra,
WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 0.51
0.17
1.71


Moisture
1 1.71
1.71
17.25**
10.13
34.14
Regimes
Error (a)
3
0.30
0.10



Variety 4
19.68
4.92
3.92*
2.78
4.22
MR x V
4
3.84
0.96
0.76
2.78
4.22
Error (b)
24
30.14
1.26


TOTAL
39 56.17



ns- not significant



CV (a) = 2.88%
**-
highly
significant
CV
(b)
=
8.58%
*- significant








APPENDIX TABLE 32. Analysis of variance for computed yield (t ha-1) (Abra, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 0.39
0.13
0.99


Moisture
1 76.81
76.81
584.70**
10.13
34.14
Regimes
Error (a)
3
0.39
0.13



Variety 4
10.33
2.58
7.77**
2.78
4.22
MR x V
4
0.55
0.14
0.41ns 2.78
4.22
Error (b)
24
7.98
0.33


TOTAL
39 96.45



ns- not significant



CV (a) = 8.36%
**-
highly
significant
CV
(b)
=
12.50%

APPENDIX TABLE 33. Analysis of variance for water use efficiency (Abra, WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
0.0047
0.0016
1.6ns


Moisture
1 0.0164
0.0164
16.4*
10.13
34.14
Regimes
Error (a)
3
0.0029
0.0010



Variety 4
0.2240
0.0560
3.79*
2.78
4.22
MR x V
4
0.0426
0.0106
0.72ns 2.78
4.22
Error (b)
24
0.3549
0.0148


TOTAL 39
0.6453




ns- significant



CV (a) = 0.00%
*- significant








CV (b) =
2.40%




APPENDIX TABLE 34. Analysis of variance for water use efficiency (Abra, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

200

OF
FREEDOM OF OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
0.0252
0.0084
1.06ns


Moisture
1 3.8751
3.8751
490.52**
10.13
34.14
Regimes
Error (a)
3
0.0238
0.0079



Variety 4
0.6204
0.1551
7.47**
2.78
4.22
MR x V
4
0.0279
0.0070
0.34ns 2.78
4.22
Error (b)
24
0.4986
0.0208


TOTAL 39
5.0709




ns- not significant



CV (a) = 0.08%
**-
highly
significant
CV
(b)
=
12.80%

APPENDIX TABLE 35. Analysis of variance for plant height at maturity (cm) (Apayao, WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 45.1
15.0
0.84ns


Moisture
1 2,544.0
2,544.0
142.92**
10.13
34.14
Regimes
Error (a)
3
53.5
17.8



Variety 4
9,361.6
2,340.4 106.04**
2.78
4.22
MR x V
4
265.1
66.3
3.00*
2.78
4.22
Error (b)
24
529.7
22.1


TOTAL 39
12,799.0




ns-not significant




CV (a) = 3.69%
**-highly
significant CV
(b)
=
4.11%
*- significant

APPENDIX TABLE 36. Analysis of variance for plant height at maturity (cm) (Apayao, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
91.101
30.367
0.609


Moisture
1 242.064
242.064
4.856ns 10.13
34.14
Regimes
Error (a)
3
149.550
49.850



Variety 4
10,415.903
2,603.976 179.556** 2.78
4.22
MR x V
4
42.489
10.622
0.733ns 2.78
4.22
Error (b)
24
348.055
14.502


TOTAL 39
11,289.163




ns-not significant



CV (a)= 7.25%
**-highly
significant CV
(b)
=
3.91%




APPENDIX TABLE 37. Analysis of variance for number of days from seeding to maximum tillering
(Apayao, WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

201

Replication 3 1.48
0.49
19.68*


Moisture
1 42.03
42.03
1,681.00**
10.13
34.14
Regimes
Error (a)
3
0.08
0.03



Variety 4
375.00
93.75
43.95**
2.78
4.22
MR x V
4
34.60
8.65
4.05*
2.78
4.22
Error (b)
24
51.20
2.13


TOTAL 39
504.38




*-
significant
CV
(a)
=
0.44%
**-
highly
significant
CV
(b)
=
4.00%

APPENDIX TABLE 38. Analysis of variance for Number of days from seeding to maximum tillering
(Apayao, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 16.10
5.37
1.28ns


Moisture
1 1.60
1.60
0.38ns 10.13
34.14
Regimes
Error (a)
3
12.60
4.20



Variety 4
1,069.15
267.29 74.77**
2.78
4.22
MR x V
4
28.65
7.16
2.00ns 2.78
4.22
Error (b)
24
85.80
3.57


TOTAL 39
1,213.90




ns- not significant



CV (a) = 4.87%
**-
highly
significant
CV
(b)
=
4.50%

APPENDIX TABLE 39. Analysis of variance for number of days from maximum tillering to booting
(Apayao, WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 7.28
2.43
0.97ns


Moisture
1 105.63
105.63
42.39**
10.13
34.14
Regimes
Error (a)
3
7.48
2.49



Variety 4
220.00
55.00
41.90**
2.78
4.22
MR x V
4
74.50
18.63
14.19**
2.78
4.22
Error (b)
24
31.50
1.31


TOTAL 39
446.38




ns- not significant



CV (a) = 5.07%
**-
highly
significant
CV
(b)
=
3.70%


APPENDIX TABLE 40. Analysis of variance for number of days from maximum tillering to booting
(Apayao, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 37.48
12.49
5.01ns


Moisture
1 9.03
9.03
3.62ns 10.13
34.14
Regimes
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

202

Error (a)
3
7.48
2.49



Variety 4
451.85
112.96
32.35**
2.78
4.22
MR x V
4
46.35
11.59
3.32*
2.78
4.22
Error (b)
24
83.80
3.49


TOTAL 39
635.98




ns- not significant



CV (a) = 4.50%
**-
highly
significant
CV
(b)
=
5.30%
*- significant

APPENDIX TABLE 41. Analysis of variance for number of days from booting to heading (Apayao, WS
2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 0.88
0.29
1.30ns


Moisture
1 2.03
2.03
9.00ns 10.13
34.14
Regimes
Error (a)
3
0.68
0.23



Variety 4
60.25
15.06
50.21**
2.78
4.22
MR x V
4
1.35
0.34
1.12ns 2.78
4.22
Error (b)
24
7.20
0.30


TOTAL 39
72.38




ns- not significant



CV (a) = 6.65%
**-
highly
significant
CV
(b)
=
7.70%

APPENDIX TABLE 42.Analysis of variance for number of days from booting to heading (Apayao, DS
2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 1.08
0.36
0.84ns


Moisture
1 0.03
0.03
0.06ns 10.13
34.14
Regimes
Error (a)
3
1.28
0.43



Variety 4
79.15
19.79
96.92**
2.78
4.22
MR x V
4
0.35
0.09
0.43ns 2.78
4.22
Error (b)
24
4.90
0.20


TOTAL 39
86.78




ns- not significant



CV (a) = 6.31%
**-
highly
significant
CV
(b)
=
4.40%

APPENDIX TABLE 43. Analysis of variance for number of days from heading to maturity (Apayao, WS
2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 6.28
2.09



Moisture
1 87.03
87.03
42.97**
10.13
34.14
Regimes
Error (a)
3
6.08
2.03



Variety 4
51.40
12.85
9.52**
2.78
4.22
MR x V
4
18.60
4.65
3.44*
2.78
4.22
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

203

Error (b)
24
32.40
1.35


TOTAL 39
201.78




**-
highly
significant
CV
(a)
=
6.04%
*- significant








CV (b) =
4.93%

APPENDIX TABLE 44. Analysis of variance for number of days from heading to maturity (Apayao, DS
2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 16.10
5.37



Moisture
1 0.00
0.00
0.00ns 10.13
34.14
Regimes
Error (a)
3
27.00
9.00



Variety 4
336.75
84.19
21.40**
2.78
4.22
MR x V
4
59.25
14.81
3.77*
2.78
4.22
Error (b)
24
94.40
3.93


TOTAL 39
533.50




ns- not significant



CV (a) = 9.30%
**-
highly
significant
CV
(b)
=
6.15%
*- significant

APPENDIX TABLE 45.Analysis of variance for leaf area index at 75 DAS (Apayao, WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
0.1673
0.0558
0.42ns


Moisture
1 0.6840
0.6840
5.17ns 10.13
34.14
Regimes
Error (a)
3
0.3986
0.1323



Variety 4
1.1992
0.2998
7.00**
2.78
4.22
MR x V
4
0.1163
0.0291
0.68ns 2.78
4.22
Error (b)
24
1.0277
0.0428


TOTAL 39
3.5912




ns- not significant



CV (a) = 9.07%
**-
highly
significant
CV
(b)
=
5.16%


APPENDIX TABLE 46. Analysis of variance for leaf area index at 75 DAS (Apayao, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
18.776
6.259
3.08ns


Moisture
1 17.490
17.490
8.59ns 10.13
34.14
Regimes
Error (a)
3
6.104
2.035



Variety 4
123.100
30.775
4.48**
2.78
4.22
MR x V
4
3.005
0.751
0.11ns 2.78
4.22
Error (b)
24
165.032
6.876


TOTAL 39
333.507




ns- not significant



CV (a)=5.42%
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

204

**-
highly
significant
CV
(b)
=
10.68%


APPENDIX TABLE 47. Analysis of variance for panicle number at maturity (Apayao, WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 597.6
199.2
2.03ns


Moisture
1 122.5
122.5
1.25ns 10.13
34.14
Regimes
Error (a)
3
293.9
98.0



Variety 4
23,871.9
5,968.0 43.08**
2.78
4.22
MR x V
4
830.8
207.7
1.50ns 2.78
4.22
Error (b)
24
3,325.0
138.5


TOTAL 39
29,041.6




ns-not significant


CV (a)= 8.50%
**-highly
significant CV
(b)
=
10.11%


APPENDIX TABLE 48. Analysis of variance for panicle number at maturity (Apayao, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 509.1
169.7
0.71ns


Moisture
1 62.5
62.5 0.26ns 10.13
34.14
Regimes
Error (a)
3
719.5
239.8



Variety 4
12,232.4
3058.1
14.83**
2.78
4.22
MR x V
4
437.8
109.4
0.92ns 2.78
4.22
Error (b)
24
4,949.9
206.2


TOTAL 39
18,911.1



ns-not significant


CV (a)= 3.94%
**-highly
significant CV
(b)
=
3.50%



APPENDIX TABLE 49. Analysis of variance for panicle length (cm) (Apayao, WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 2.39
0.80
1.75


Moisture
1 6.40
6.40
14.10*
10.13
34.14
Regimes
Error (a)
3
1.36
0.45



Variety 4
83.41
20.85
26.27**
2.78
4.22
MR x V
4
3.73
0.93
1.17ns 2.78
4.22
Error (b)
24
19.05
0.79


TOTAL 39
116.34




ns-not significant



CV (a) = 2.93%
**-highly
significant CV
(b)
=
3.88%
*- significant


Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

205









APPENDIX TABLE 50. Analysis of variance for panicle length (cm) (Apayao, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 0.23
0.08
0.12


Moisture
1 5.94
5.94
9.07ns 10.13
34.14
Regimes
Error (a)
3
1.97
0.66



Variety 4
52.68
13.17
41.82**
2.78
4.22
MR x V
4
2.62
0.65
2.08ns 2.78
4.22
Error (b)
24
7.56
0.32


TOTAL
39 70.99



ns-not significant


CV (a) = 0.81%
**-highly
significant CV
(b)
=
2.66%


APPENDIX TABLE 51. Analysis of variance for total number of grains per panicle (Apayao, WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
622.10
207.37
2.16


Moisture
1 115.60
115.60
1.20ns 10.13
34.14
Regimes
Error (a)
3
288.20
96.07



Variety 4
24,119.65
6,029.91 43.12**
2.78
4.22
MR x V
4
808.15
202.04
1.44ns 2.78
4.22
Error (b)
24
3,356.20
139.84


TOTAL 39
29,309.90




ns- not significant



CV (a)= 8.42%
**-
highly
significant
CV
(b)
=
10.15%



APPENDIX TABLE 52. Analysis of variance for total number of grains per panicle (Apayao, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
753.28
251.09
1.00


Moisture
1 2,907.03
2,907.03
11.57*
10.13
34.14
Regimes
Error (a)
3
753.68
251.23



Variety 4
19,084.25
4,771.06 15.31**
2.78
4.22
MR x V
4
2,495.35
623.84
2.00ns 2.78
4.22
Error (b)
24
7,476.80
311.53


TOTAL 39
33,470.38




ns- not significant



CV (a) = 11.82%
**-
highly
significant
CV
(b)
=
13.16%
*- significant








APPENDIX TABLE 53. Analysis of variance for number of filled grains per panicle (Apayao, WS 2010)
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

206

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
597.60
199.20
2.03


Moisture
1 122.50
122.50
1.25ns 10.13
34.14
Regimes
Error (a)
3
293.90
97.97



Variety 4
23,871.85
5,967.96 43.08**
2.78
4.22
MR x V
4
830.75
207.69
0.97ns 2.78
4.22
Error (b)
24
3,325.00
138.54


TOTAL 39
29,041.60




ns-not significant


CV (a)= 2.29%
**-highly
significant CV
(b)
=
2.86%

APPENDIX TABLE 54. Analysis of variance for number of filled grains per panicle (Apayao, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
394.72
131.57
0.88


Moisture
1 1,515.36
1,515.36
10.19*
10.13
34.14
Regimes
Error (a)
3
446.24
148.75



Variety 4
18,597.15
4,649.29 22.08**
2.78
4.22
MR x V
4
1,487.02
371.76
1.77ns 2.78
4.22
Error (b)
24
5,054.06
210.59


TOTAL 39
27,494.54




ns-not significant


CV (a) = 2.81%
**-highly
significant CV
(b)
=
5.24%
*-
significant



APPENDIX TABLE 55. Analysis of variance for filled grain ratio (Apayao, WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 62.60
20.87
1.92ns


Moisture
1 211.60
211.60
19.47*
10.13
34.14
Regimes
Error (a)
3
32.60
10.87



Variety 4
1,730.25
432.56 22.60**
2.78
4.22
MR x V
4
287.65
71.91
3.76*
2.78
4.22
Error (b)
24
459.30
19.14


TOTAL 39
2,784.00




ns- not significant



CV (a)= 4.84%
**-highly
significant CV
(b)
=
6.43%
*- significant

APPENDIX TABLE 56. Analysis of variance for filled grain ratio (Apayao, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 35.59
11.86
0.51ns


Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

207

Moisture
1 35.08
35.08
1.51ns 10.13
34.14
Regimes
Error (a)
3
69.74
23.25



Variety 4
2,411.27
602.82 12.60**
2.78
4.22
MR x V
4
180.20
45.05
0.94ns 2.78
4.22
Error (b)
24
1,147.97
47.83


TOTAL 39
3,879.85




ns-not significant


CV (a)= 8.86%
**-highly
significant CV
(b)
=
9.84%

APPENDIX TABLE 57. Analysis of variance for weight of 1000 filled grains (Apayao, WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 0.56
0.19
1.78


Moisture
1 0.44
0.44
4.23ns 10.13
34.14
Regimes
Error (a)
3
0.31
0.10



Variety 4
217.82
54.46
121.40**
2.78
4.22
MR x V
4
2.22
0.55
1.24ns 2.78
4.22
Error (b)
24
10.77
0.45


TOTAL 39
232.11




ns-not significant


CV (a)= 1.24%
**-highly
significant CV
(b)
=
2.57%




APPENDIX TABLE 58. Analysis of variance for weight of 1000 filled grains (Apayao, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 3.27
1.09
0.25


Moisture
1 0.04
0.04
0.01ns 10.13
34.14
Regimes
Error (a)
3
13.09
4.36



Variety 4
209.64
52.41
15.71**
2.78
4.22
MR x V
4
21.52
5.38
1.61ns 2.78
4.22
Error (b)
24
80.05
3.34


TOTAL 39
327.61




ns-not significant


CV (a)= 8.47%
**-highly
significant CV
(b)
=
7.40%

APPENDIX TABLE 59. Analysis of variance for total dry matter weight (Apayao, WS 2010)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
3,788.03
1,262.68
3.83ns


Moisture
1 37,088.10
37,088.10
112.61**
10.13
34.14
Regimes
Error (a)
3
988.05
329.35



Variety 4
34,660.71
8,665.18 5.81**
2.78
4.22
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

208

MR x V
4
277.71
69.43
0.05ns 2.78
4.22
Error (b)
24
35,796.68
1,491.53


TOTAL 39
112,599.28




ns- not significant



CV (a) = 6.07%
**-
highly
significant
CV
(b)
=
12.92%


APPENDIX TABLE 60. Analysis of variance fortTotal dry matter weight (Apayao, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
2,271.03
757.01
0.20ns


Moisture
1 93.03
93.03
0.02ns 10.13
34.14
Regimes
Error (a)
3
11,342.53
3,780.84



Variety 4
57,711.09
14,427.77 8.77** 2.78
4.22
MR x V
4
2,142.66
535,67
0.33ns 2.78
4.22
Error (b)
24
39,465.95
1,644.42


TOTAL 39
113,026.28




ns- not significant



CV (a) = 0.00%
**-
highly
significant
CV
(a)
=
2.19%




APPENDIX TABLE 61. Analysis of variance for harvest index (Apayao, WS 2010)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 28.23
9.41
0.67ns


Moisture
1 80.94
80.94
5.72ns 10.13
34.14
Regimes
Error (a)
3
42.45
14.15



Variety 4
1,821.29
455.32 62.63**
2.78
4.22
MR x V
4
38.85
9.71
1.34ns 2.78
4.22
Error (b)
24
174.48
7.27


TOTAL 39
2,186.24




ns- not significant



CV (a) = 10.21%
**-
highly
significant
CV
(b)
=
7.32%

APPENDIX TABLE 62. Analysis of variance for harvest index (Apayao, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 75.97
25.32
4.60ns


Moisture
1 205.03
205.03
37.22**
10.13
34.14
Regimes
Error (a)
3
16.52
5.51



Variety 4
983.64
245.91
16.94**
2.78
4.22
MR x V
4
97.92
24.48
1.69ns 2.78
4.22
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

209

Error (b)
24
348.37
14.52


TOTAL 39
1,727.45




ns- not significant



CV (a) = 5.36%
**-
highly
significant
CV
(b)
=
8.72%

APPENDIX TABLE 63. Analysis of variance for grain yield (kg) (Apayao, WS 2010)

SOURCE
DEGREES
SUM
MEAN
COMPUTED
TABULATED
OF
OF
OF
OF SQUARES
F
F
VARIATION
FREEDOM
SQUARES
0.05 0.01
Replication 3 97,210.98
32,403.66
0.28ns


Moisture
1 7,954,945.11
7,954,945.11
63.14**
10.13
34.14
Regimes
Error (a)
3
345,191.38
115,063.79



Variety 4
10,123,705.98
2,530,926.50 5.48** 2.78
4.22
MR x V
4
1,082,525.17
270,631.29
0.58ns 2.78
4.22
Error (b)
24
11,092,130.98
462,172.12


TOTAL 39
30,695,709.59



ns-not significant


CV (a) = 4.44%
**-highly
significant CV
(b)
=
9.27%


APPENDIX TABLE 64. Analysis of variance for grain yield (kg) (Apayao, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
887,726.37
295,908.79
5.98


Moisture
1 280,361.58
280,361.58
5.67ns 10.13
34.14
Regimes
Error (a)
3
148,401.90
49,467.30



Variety 4
37,985,861.88
9,496,465.47 37.77** 2.78
4.22
MR x V
4
495,737.58
123,934.40
0.94ns 2.78
4.22
Error (b)
24
6,033,703.83
251,404.33


TOTAL 39
45,831,793.14




ns- not significant



CV (a)= 6.38%
**-
highly
significant
CV
(b)
=
12.96%

APPENDIX TABLE 65. Analysis of variance for computed yield (t ha-1) (Apayao, WS 2010)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 0.31
0.10
0.29


Moisture
1 24.03
24.03
66.92**
10.13
34.14
Regimes
Error (a)
3
1.08
0.36



Variety 4
30.15
7.54
5.30**
2.78
4.22
MR x V
4
3.36
0.84
0.59ns 2.78
4.22
Error (b)
24
34.15
1.42


TOTAL
39 93.08



ns- not significant



CV (a)= 14.36%
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

210

**-
highly
significant
CV
(b)
=
13.90%

APPENDIX TABLE 66. Analysis of variance for computed yield (tha-1) (Apayao, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 3.78
1.26
25.07


Moisture
1 1.80
1.80
35.83**
10.13
34.14
Regimes
Error (a)
3
0.15
0.05



Variety 4
103.56
25.89
48.09**
2.78
4.22
MR x V
4
1.81
0.45
0.84ns 2.78
4.22
Error (b)
24
12.92
0.54


TOTAL 39
124.02




ns- not significant



CV (a)= 0.00%
**-
highly
significant
CV
(b)
=
4.26%


APPENDIX TABLE 67. Analysis of variance for water use efficiency (Apayao, WS 2010)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
0.00065
0.00022
0.32ns


Moisture
1 0.03080
0.03080
44.63**
10.13
34.14
Regimes
Error (a)
3
0.00207
0.00069



Variety 4
0.06652
0.01663
6.14**
2.78
4.22
MR x V
4
0.00669
0.00167
0.62ns 2.78
4.22
Error (b)
24
0.06496
0.00271


TOTAL 39
0.17168




ns-not significant



CV (a) = 3.19%
**-highly
significant CV
(b)
=
3.24%

APPENDIX TABLE 68. Analysis of variance for water use efficiency (Apayao, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
0.0047
0.0016
53.33**


Moisture
1 0.0325
0.0325
1,083.33**
10.13
34.14
Regimes
Error (a)
3
0.0001
0.00003



Variety 4
0.1441
0.360
42.75**
2.78
4.22
MR x V
4
0.0096
0.0024
2.84*
2.78
4.22
Error (b)
24
0.0202
0.0008


TOTAL 39
0.2112




*- significant



CV (a)= 0.00%
**-highly
significant CV
(b)
=
4.20%

Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

211

APPENDIX TABLE 69. Analysis of variance for plant height (cm) at maturity (Benguet, Aug 2010-Feb
2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 97.64
32.55



Moisture
1 825.37
825.37
27.02**
10.13
34.14
Regimes
Error (a)
3
91.64
30.55



Variety 4
11,266.14
2,816.54 31.50**
2.78
4.22
MR x V
4
588.43
147.11
1.65ns
2.78 4.22
Error (b)
24
2,146.26
89.43


TOTAL 39
15,015.48




ns- not significant



CV (a) = 7.08%
**-highly
significant CV
(b)
=
12.12%


APPENDIX TABLE 70. Analysis of variance for plant height (cm) at maturity (Benguet, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 83.31
27.77
0.83ns


Moisture
1 2,946.20
2,946.20
88.39**
10.13
34.14
Regimes
Error (a)
3
100.00
33.33



Variety 4
39,537.33
9,884.33 1,943.70**
2.78
4.22
MR x V
4
364.95
91.24
17.94*
2.78
4.22
Error (b)
24
122.05
5.09


TOTAL 39
43,153.83




ns- not significant



CV (a) = 6.14%
**-highly
significant CV
(b)
=
2.40%
*- significant

APPENDIX TABLE 71. Analysis of variance for number of days from seeding to tillering (Benguet, Aug
2010-Feb 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 9.09
3.03
0.00ns


Moisture
1 0.00
0.00
0.00ns
10.13 34.14
Regimes
Error (a)
3
0.00
0.00



Variety 4
1,573.42
393.36 199.06**
2.78
4.22
MR x V
4
0.00
0.00
0.00ns
2.78 4.22
Error (b)
24
47.43
1.98


TOTAL 39
1,629.94




*-
significant
CV
(a)
=
0.00%
**-
highly
significant
CV
(b)
=
2.30%

Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

212

APPENDIX TABLE 72. Analysis of variance for number of days from seeding to maximum tillering
(Benguet, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 8.40
2.80
28.00*


Moisture
1 864.90
864.90
8,649.00**
10.13
34.14
Regimes
Error (a)
3
0.30
0.10



Variety 4
12,834.40
3,208.60 1,578.00** 2.78
4.22
MR x V
4
425.60
106.40
52.33**
2.78
4.22
Error (b)
24
48.80
2.00


TOTAL 39
14,182.40




*- significant



CV (a) = 0.39%
**-
highly
significant
CV
(b)
=
1.80%
APPENDIX TABLE 73. Analysis of variance for number of days from maximum tillering to booting
(Benguet, Aug 2010-Feb 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 22.90
7.63
16.34*


Moisture
1 0.40
0.40
0.85ns 10.13
34.14
Regimes
Error (a)
3
1.40
0.47



Variety 4
868.85
217.21
81.20**
2.78
4.22
MR x V
4
3.35
0.84
0.31ns 2.78
4.22
Error (b)
24
64.20
2.68


TOTAL 39
961.10




ns- not significant



CV (a) = 2.38%
**-
highly
significant
CV
(b)
=
5.70%
*- significant

APPENDIX TABLE 74. Analysis of variance for number of days from maximum tillering to booting
(Benguet, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 68.00
22.67
1.68ns


Moisture
1 176.40
176.40
13.09*
10.13
34.14
Regimes
Error (a)
3
40.40
13.47



Variety 4
1,421.35
355.34 53.43**
2.78
4.22
MR x V
4
47.85
11.96
1.80ns 2.78
4.22
Error (b)
24
159.60
6.65


TOTAL 39
1,913.60




ns- not significant



CV (a) = 11.32%
**-
highly
significant
CV
(b)
=
8.00%
*- significant

APPENDIX TABLE 75. Analysis of variance for number of days from booting to heading (Benguet, Aug
2010-Feb 2011)
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

213

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 1.70
0.57
1.21ns


Moisture
1 0.40
0.40
0.86ns 10.13
34.14
Regimes
Error (a)
3
1.40
0.47



Variety 4
182.65
45.66
130.46**
2.78
4.22
MR x V
4
3.35
0.84
2.39ns 2.78
4.22
Error (b)
24
8.40
0.35


TOTAL 39
197.90




ns- not significant



CV (a) = 4.10%
**-
highly
significant
CV
(b)
=
4.70%
APPENDIX TABLE 76. Analysis of variance for number of days from booting to heading (Benguet, DS
2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 1.60
0.53
1.33ns


Moisture
1 0.40
0.40
0.00ns 10.13
34.14
Regimes
Error (a)
3
1.20
0.40



Variety 4
174.35
43.59
145.29**
2.78
4.22
MR x V
4
2.85
0.71
2.38ns 2.78
4.22
Error (b)
24
7.20
0.30


TOTAL 39
187.60




ns- not significant



CV (a) = 3.81%
**-
highly
significant
CV
(b)
=
3.30%

APPENDIX TABLE 77. Analysis of variance for number of days from heading to maturity (Benguet, Aug
2010-Feb 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 38.27
12.76



Moisture
1 1,729.23
1,729.23
53.88**
10.13
34.14
Regimes
Error (a)
3
96.28
32.09



Variety 4
217.90
54.48
2.22ns 2.78
4.22
MR x V
4
125.90
31.48
1.28ns 2.78
4.22
Error (b)
24
588.20
24.51


TOTAL 39
2,795.78




**-
highly
significant
CV
(a)
=
13.12%
*- significant








CV (b) =
11.47%

APPENDIX TABLE 78. Number of days from heading to maturity (Benguet, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 32.08
10.69



Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

214

Moisture
1 235.23
235.23
40.38**
10.13
34.14
Regimes
Error (a)
3
17.48
5.83



Variety 4
547.85
136.96
36.44**
2.78
4.22
MR x V
4
111.15
27.79
7.39**
2.78
4.22
Error (b)
24
90.20
3.76


TOTAL 39
1,033.98




**-
highly
significant
CV
(a)
=
4.80%










CV (b) =
3.86%


APPENDIX TABLE 79. Analysis of variance for leaf area index at 75 DAS (Benguet, Aug 2010-Feb 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 0.31
0.10



Moisture
1 3.80
3.80
87.63**
10.13
34.14
Regimes
Error (a)
3
0.13
0.04



Variety 4
0.32
0.08
1.25ns
2.78 4.22
MR x V
4
0.29
0.08
1.13ns 2.78
4.22
Error (b)
24
1.57
0.07


TOTAL 39
6.44




ns- not significant



CV (a) = 13.95%
**-
highly
significant
CV
(b)
=
10.81%

APPENDIX TABLE 80. Analysis of variance for leaf area index at 75 DAS (Benguet, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 2.35
0.78



Moisture
1 40.40
40.40
40.56**
10.13
34.14
Regimes
Error (a)
3
2.99
1.00



Variety 4
8.37
2.09
1.37ns 2.78
4.22
MR x V
4
1.46
0.36
0.23ns 2.78
4.22
Error (b)
24
36.61
1.53


TOTAL
39 92.17



ns- not significant



CV (a) = 10.18%
**-
highly
significant
CV
(b)
=
12.77%

APPENDIX TABLE 81. Panicle number at maturity (Benguet, Aug 2010-Feb 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
158.88
52.96



Moisture
1 697.23
697.23
34.14**
10.13
34.14
Regimes
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

215

Error (a)
3
61.28
20.43



Variety 4
459.10
114.78
2.28ns
2.78 4.22
MR x V
4
459.40
114.85
2.28ns
2.78 4.22
Error (b)
24
1,207.10
50.30


TOTAL 39
3,042.98




ns- not significant



CV (a) = 3.67%
**-
highly
significant
CV
(b)
=
6.62%


APPENDIX TABLE 82. Analysis of variance for panicle number at maturity (Benguet, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 72.48
24.16



Moisture
1 990.03
990.03
8.62ns 10.13
34.14
Regimes
Error (a)
3
344.48
114.83



Variety 4
5,577.85
1,349.46 13.08**
2.78
4.22
MR x V
4
675.35
168.84
1.57ns
2.78 4.22
Error (b)
24
2,572.80
107.20


TOTAL 39
10,232.98




ns- not significant



CV (a) = 6.35%
**-
highly
significant
CV
(b)
=
6.07%

APPENDIX TABLE 83. Analysis of variance for panicle length (cm) (Benguet, Aug 2010-Feb 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 3.35
1.12
0.30


Moisture
1 10.61
10.61
2.89ns 10.13
34.14
Regimes
Error (a)
3
11.02
3.67



Variety 4
287.26
71.82
74.16**
2.78
4.22
MR x V
4
12.89
3.22
3.33ns 2.78
4.22
Error (b)
24
23.24
0.97


TOTAL 39
348.38




ns- not significant



CV (a) = 10.11%
**-
highly
significant
CV
(b)
=
5.24%

APPENDIX TABLE 84. Analysis of variance for panicle length (cm) (Benguet, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 16.93
5.64

Moisture
1 1.52
1.52 0.25ns
10.13 34.14
Regimes
Error (a)
3
18.27
6.09



Variety 4
250.45
62.61
15.98**
2.78
4.22
MR x V
4
31.74
7.94
2.02ns
2.78 4.22
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

216

Error (b)
24
94.05
3.92


TOTAL 39
412.96



ns- not significant



CV (a) = 12.64%
**-
highly
significant
CV
(b)
=
10.14%

APPENDIX TABLE 85. Analysis of variance for total number of grains per panicle (Benguet, Aug 2010-Feb
2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
1,821.80
607.27

Moisture
1 1,060.90
1,060.90 1.48ns 10.13
34.14
Regimes
Error (a)
3
2,150.10
716.70



Variety 4

4,743.65
1,185.91
2.90*
2.78
4.22
MR x V
4
1,771.85
442.96
1.08ns
2.78 4.22
Error (b)
24
9,812.10
408.84


TOTAL 39
21,360.40



ns- not significant



CV (a) = 4.82%
*- significant








CV (b) =
3.42%

APPENDIX TABLE 86. Analysis of variance for total number of grains per panicle (Benguet, DS 2011)
SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
296.20
98.73



Moisture
1 40.00
40.00
0.24ns
10.13 34.14
Regimes
Error (a)
3
483.40
161.13



Variety 4
12,613.60
3,153.40 24.55** 2.78
4.22
MR x V
4
12,436.00
3,109.00
24.20**
2.78
4.22
Error (b)
24
3,082.40
128.433


TOTAL 39
28,951.60




ns- not significant



CV (a) = 6.46%
**-
highly
significant
CV
(b)
=
11.58%

APPENDIX TABLE 87. Analysis of variance for number of filled grains per panicle (Benguet, Aug 2010-
Feb 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
252.28
84.09



Moisture
1 319.23
319.23
0.79ns
10.13 34.14
Regimes
Error (a)
3
1,199.28
399.76



Variety 4
8,648.60
2,162.15 16.42** 2.78
4.22
MR x V
4
3,052.40
763.10
5.79**
2.78
4.22
Error (b)
24
3,160.20
131.68


TOTAL 39
16,631.98




ns- not significant



CV (a) = 4.87%
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

217

**-
highly
significant
CV
(b)
=
2.98%

APPENDIX TABLE 88. Analysis of variance for number of filled grains per panicle (Benguet, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
371.08
123.69



Moisture
1 1,550.03
1,550.03
9.72ns
10.13 34.14
Regimes
Error (a)
3
478.08
159.36



Variety 4
11,362.15
2,840.54 40.89**
2.78
4.22
MR x V
4
11,126.35
2,781.59
40.04**
2.78
4.22
Error (b)
24
1,667.10
69.46


TOTAL 39
26,554.78




ns- not significant



CV (a) = 4.87%
**-
highly
significant
CV
(b)
=
2.98%

APPENDIX TABLE 89. Analysis of variance for filled grain ratio (%) (Benguet, Aug 2010-Feb 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
297.55
99.18



Moisture
1 649.64
649.64
3.32ns 10.13
34.14
Regimes
Error (a)
3
587.08
195.69



Variety 4
1,310.43
327.61
1.38ns
2.78 4.22
MR x V
4
235.01
58.75
0.24ns
2.78 4.22
Error (b)
24
5,678.55
236.61


TOTAL 39
8,758.55




ns- not significant



CV (a) = 15.99%










CV (b) =
17.10%
APPENDIX TABLE 90. Analysis of variance for filled grain ratio (%) (Benguet, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 46.25
15.42
0.78


Moisture
1 796.56
796.56
40.23**
10.13
34.14
Regimes
Error (a)
3
59.40
19.80



Variety 4
2,122.62
530.66 18.32**
2.78
4.22
MR x V
4
1,015.18
253.80
8.76**
2.78
4.22
Error (b)
24
695.12
28.96


TOTAL 39
4,735.13




**- highly significant

CV (a) = 6.76%
CV (b) =
8.18%



Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

218

APPENDIX TABLE 91. Analysis of variance for 1000 filled grain weight (g) (Benguet, Aug 2010-Feb
2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 4.04
1.35
35.09


Moisture
1 0.05
0.05
1.28ns 10.13
34.14
Regimes
Error (a)
3
0.12
0.04



Variety 4
344.41
86.10
83.36**
2.78
4.22
MR x V
4
5.51
1.38
1.33ns 2.78
4.22
Error (b)
24
24.79
1.03


TOTAL 39
378.91




ns- not significant



CV (a) = 0.76%
**-
highly
significant
CV
(b)
=
3.98%

APPENDIX TABLE 92. 1000 filled grain weight (g) (Benguet, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication
3 3.20 1.07 0.18

Moisture
1 0.16
0.16 0.03ns 10.13
34.14
Regimes
Error (a)
3
18.17
6.06



Variety 4
531.45
132.86
109.17**
2.78
4.22
MR x V
4
46.47
11.62
9.55**
2.78
4.22
Error (b)
24
29.21
1.22


TOTAL 39
628.65



ns- not significant



CV (a) = 13.30%
**-
highly
significant
CV
(b)
=
5.96

APPENDIX TABLE 93. Analysis of variance for total dry matter weight (Benguet, Aug 2010-Feb 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication
3
1,017.95 339.32


Moisture
1 19,580.63
19,580.63
130.50**
10.13
34.14
Regimes
Error (a)
3
450.13
150.04



Variety 4
4,152.48
1,038.12 15.28**
2.78
4.22
MR x V
4
2,789.13
697.28
10.26**
2.78
4.22
Error (b)
24
1,629.80
67.91


TOTAL 39





**-
highly
significant
CV
(a)
=
16.99%










CV (b) =
11.43%
APPENDIX TABLE 94. Analysis of variance for total dry matter weight (Benguet, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

219

OF
FREEDOM OF OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
5,293.98
1,764.66



Moisture
1 37,976.40
37,976.40
39.19**
10.13
34.14
Regimes
Error
(a)
3
2,906.49 968.83


Variety 4
27,298.89
6,824.72 4.07*
2.78
4.22
MR x V
4
2,814.66
703.66
0.42ns
2.78 4.22
Error (b)
24
40,202.10
1,675.09


TOTAL 39
116,492.51




ns- not significant



CV (a) = 3.93%
**-
highly
significant
CV
(a)
=
5.46%
*- significant

APPENDIX TABLE 95. Analysis of variance for harvest index (Benguet, Aug 2010-Feb 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
144.93
48.31



Moisture
1 21.76
21.76
1.35ns 10.13
34.14
Regimes
Error (a)
3
48.28
16.09



Variety 4
377.34
94.33
6.46**
2.78
4.22
MR x V
4
135.67
33.92
2.32ns
2.78 4.22
Error (b)
24
350.45
14.60


TOTAL 39
1,078.42




ns- not significant



CV (a) = 11.78%
**-
highly
significant
CV
(b)
=
11.22%

APPENDIX TABLE 96. Analysis of variance for harvest index (Benguet, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 11.67
3.89



Moisture
1 1,374.76
1,374.76
52.52**
10.13
34.14
Regimes
Error (a)
3
78.52
26.17



Variety 4
134.93
33.73
2.85*
2.78
4.22
MR x V
4
54.45
13.61
1.15ns
2.78 4.22
Error (b)
24
283.88
11.83


TOTAL 39
1,938.20




ns- not significant



CV (a) = 5.39%
**-
highly
significant
CV
(b)
=
5.64%
*- significant
APPENDIX TABLE 97. Analysis of variance for grain yield (kg) (Benguet, Aug 2010-Feb 2011)

SOURCE
DEGREES
SUM
MEAN
COMPUTED
TABULATED
OF
OF
OF
OF
F
F
VARIATION
FREEDOM
SQUARES
SQUARES
0.05 0.01
Replication 3
547,299.97
182,433.32

Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

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220

Moisture
1 6,775,676.92
6,775,676.92
274.60**
10.13
34.14
Regimes
Error (a)
3
74,022.22
24,674.07



Variety 4
2,141,506.13
535,376.53 9.23** 2.78 4.22
MR x V
4
825,748.20
206,437.05
3.56*
2.78
4.22
Error (b)
24
1,390,978.84
57,597.45


TOTAL 39
11,755,232.28



**- highly significant

CV (a) = 2.50%
*- significant








CV (b) =
4.14%

APPENDIX TABLE 98. Analysis of variance for grain yield (kg) (Benguet, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3
17,045.16
5,681.719



Moisture
1 21,413.76
21,413.76
7.47ns
10.13 34.14
Regimes
Error (a)
3
8,597.55
2,865.85



Variety 4
527,756.78
131,939.19 33.86** 2.78
4.22
MR x V
4
110,784.10
27,696.03
7.11**
2.78
4.22
Error (b)
24
93,503.24
3,895.97


TOTAL 39
779,100.58




ns- not significant



CV (a) = 7.64%
**-
highly
significant
CV
(b)
=
8.28%

APPENDIX TABLE 99. Analysis of variance for computed yield (t ha-1) (Benguet, Aug 2010-Feb 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 1.67
0.56



Moisture
1 20.45
20.45
228.05**
10.13
34.14
Regimes
Error (a)
3
0.27
0.09



Variety 4
6.50
1.63
9.04**
2.78
4.22
MR x V
4
2.60
0.65
3.61*
2.78
4.22
Error (b)
24
4.31
0.18


TOTAL
39 35.79



**- highly significant

CV (a) = 9.76%
*- significant








CV (b) =
9.71%


APPENDIX TABLE 100. Analysis of variance for computed yield (t ha-1) (Benguet, DS 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF VARIATION
FREEDOM
OF SQUARES
OF SQUARES
F
F
0.05 0.01
Replication 3 0.05
0.02
1.98


Moisture Regimes
1
0.07
0.07
7.54ns
10.13 34.14
Error (a)
3
0.03
0.01



Variety 4
1.60
0.40
34.20**
2.78
4.22
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

---

221

MR x V
4
0.34
0.08
7.21**
2.78
4.22
Error (b)
24
0.28
0.01



TOTAL 39
2.36



ns- not significant



CV (a) = 3.84%
**-
highly
significant
CV
(b)
=
4.27%

APPENDIX TABLE 101.Analysis of variance for water use efficiency (Benguet, Aug 2010-Feb 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF
FREEDOM
OF
OF
F
F
VARIATION
SQUARES
SQUARES
0.05 0.01
Replication 3 0.31
0.10
1.32


Moisture
1 0.02
0.02
0.25ns
10.13 34.14
Regimes
Error (a)
3
0.24
0.08



Variety 4
0.45
0.11
1.22ns
2.78 4.22
MR x V
4
0.29
0.07
0.78ns
2.78 4.22
Error (b)
24
2.24
0.09


TOTAL 39
3.55




ns- not significant



CV (a) = 5.43%










CV (b) =
4.37%

APPENDIX TABLE 102. Analysis of variance for water use efficiency (Benguet, Mar-Nov 2011)

SOURCE
DEGREES OF
SUM
MEAN
COMPUTED
TABULATED
OF VARIATION
FREEDOM
OF SQUARES
OF SQUARES
F
F
0.05 0.01
Replication 3
0.000
0.000
2.08


Moisture Regimes
1
0.000
0.000
8.53ns
10.13 34.14
Error (a)
3
0.000
0.000



Variety 4
0.003
0.001
26.86**
2.78
4.22
MR x V
4
0.001
0.000
7.06**
2.78
4.22
Error (b)
24
0.001
0.000



TOTAL 39
0.005




ns- not significant



CV (a) = 0%
**-highly
significant CV
(b)
=0%
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes
in Different Agro-ecosystems /Virginia A. Tapat. 2012

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223 
 
BIOGRAPHICAL SKETCH
 

The author is the eldest of two children of the late Marcelino B. Atmosfera
and Filomena B. Kuezon of Dolores, Abra and Inopacan, Leyte, respectively. She
was born on December 31, 1969 in Inopacan, Leyte.

She finished her elementary education in Mudiit Elementary School,
Mudiit, Dolores, Abra. She enrolled in Abra State Institute of Sciences and
Technology (ASIST), Lagangilang, Abra and graduated in 1985 as Salutatorian.
She spent her college days at ASIST and obtained a degree of Bachelor of Science
in Agricultural Education major in Agronomy and minor in Animal Husbandry in
1989 where she graduated as Cum Laude. Moreover, she finished Master in
Community Development in 2000 at the Benguet State University-Open
University. In order to gain more technical knowledge, she pursued another
master’s degree major in Agronomy and minor in Soil Science.

She has been with the Department of Agriculture-Regional Field Office,
Cordillera Administrative Region since 1989 starting as an Agricultural
Development Specialist (ADS) to her current position of a Senior Agriculturist
and concurrently designated as the Officer-In Charge (OIC) of the Operations
Division.

Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes 
in Different Agro‐ecosystems /Virginia A. Tapat. 2012 

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224 
 

In 1996, she got married to Vincent Emerencio T. Tapat of Lagangilang,
Abra. The couple now resides at San Luis Village, Baguio City and has a
provincial address of Ducam, Dolores, Abra.



VIRGINIA
ATMOSFERA-TAPAT
Growth and Yield Performance of Rice Varieties Grown under Two Moisture Regimes 
in Different Agro‐ecosystems /Virginia A. Tapat. 2012 

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Document Outline

• Growth and Yield Performance ofRice Varieties Grown under Two Moisture Regimes in Different Agroecosystems
  • BIBLIOGRAPHY
  • INTRODUCTION
  • REVIEW OF LITERATURE
  • MATERIALS AND METHODS
  • RESULTS AND DISCUSSION
  • SUMMARY, CONCLUSIONS AND RECOMMENDATION
  • LITERATURE CITED
  • APPENDICES
  • BIOGRAPHICAL SKETCH

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