BIBLIOGRAPHY BALICDANG, JANET S. OCTOBER...
BIBLIOGRAPHY
BALICDANG, JANET S. OCTOBER 2007. Growth and Yield of Chinese Kale
(Brassica oleracea var. alboglabra) as Affected by Duration of Weed Control. Benguet
State University, La Trinidad, Benguet.
Adviser: Pepe E. Toledo, PhD
ABSTRACT
The study was conducted at the Balili Experimental Station, Benguet State
University, La Trinidad, Benguet from June to July 2007 to determine the effects of
weeding durations on the growth and yield, to establish the best time of weeding, and to
assess the economics of the various weeding durations in Chinese kale production.
Results showed that plants weed-free from transplanting up to harvesting and
weed-free for 30 days after transplanting (DAT) were comparable but considerably
required longer duration of weeding than the other treatments.
Small flower galinsoga (Galinsoga parviflora Cav.) was identified as the
predominantly weed species growing in association with the crop while the minor were
goosegrass (Eleusine indica L.) and crabgrass (Digitaria sanguinalis L.). The
population of G. parviflora at harvest was significantly higher in the unweeded plots than
the rest of the treatments.
Plant growth increment measured in one, two and three weeks after transplanting
were not significant. But on the fourth measurement, growth increment was significantly
higher in plants weed-free for 30 DAT. On the fifth and sixth measurements, weed-free
plants for 30 DAT had markedly higher growth comparable to weed-free and those weed-
free for 20 DAT but were considerably higher than those plants weed-free for 10 DAT
and unweeded plots. Weed-free plants had the highest growth increment on the seventh
measurement. For the final height at harvest, weed-free plants markedly had the tallest
comparable with those plants at 30 DAT.
Plants kept weed-free and plants weeded for 30 DA T significantly produced
higher average marketable weight per plant, marketable, total, computed yields, and
benefit:cost ratio. Yield reduction ranges from 5.69 to 82.11%.
ii
TABLE OF CONTENTS
Page
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Abstract………... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
iii
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
REVIEW OF LITERATURE
Description of the Crop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
Yield Losses Due to Weeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
Crop-Weed Competition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
Weed Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
MATERIALS AND METHODS
Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
RESULTS AND DISCUSSION
Weeding Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10
Identified Weed Species and Population . . . . . . . . . . . . . . . . . . . . . . . .
10
Growth Increment and Final Height . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
Crop Survival . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12
Average Weight, Non-marketable and Marketable Yields . . . . . . . . . .
12
Total and Computed Yields and Benefit:Cost Ratio . . . . . . . . . . . . . . .
14
iii
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20
Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21
LITERATURE CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22
APPENDICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24
iv
INTRODUCTION
Vegetable production is a major industry in the highlands where majority of the
people in the Cordillera are engaged because they gain profit from producing vegetable
crops and the climatic conditions are favorable for their growth and development.
Chinese kale is an introduced crop in the Cordilleras. It offers benefits like a
source of income and one of the leafy vegetables with the best eating quality. However,
in growing vegetable crops, factors like weed occurrence should be considered. Weeds
compete with crop plants for sunlight, water, nutrients and space and their growth must
be limited to obtain a good yield of any food crop. Weed management strategies should
be employed to limit the deleterious effects in growing vegetables crops. If weeds are
able to utilize a sufficient amount of some growth factors to the detriment of the crop, the
results can be, and most often is, an adverse effect on crop yield in terms of quality and
volume. Therefore, it is important that weeds are controlled to prevent their competition
with the vegetable crop grown.
The presence of weeds is a serious garden problem. They rob vegetable crops of
sunlight, water and nutrients. They also provide hiding places for insects and serve as a
source of crop diseases.
The existence of weeds in crop production is one major problem of vegetable
growers. Villareal and Wallace (1969) stated that many adapted weed species are
identified in the farmers’ fields that caused losses due to competition for light, mineral
nutrients, space and water. They also harbor insect pests and diseases that impair plant
growth and development resulting to poor and low yield.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
2
To attain satisfactory crop growth, development and good yield, weed control
should be done at the earliest stage of crop growth during the cropping season. Thus, this
study is conceptualized.
The study was conducted at the Balili Experimental Station, Benguet State
University, La Trinidad, Benguet from June to July 2007 to determine the effects of
weeding durations on the growth and yield, to establish the best time of weeding, and to
assess the economics of the various weeding durations in Chinese kale production.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
REVIEW OF LITERATURE
Description of the Crop
Chinese broccoli or Chinese kale, is a slightly bitter leaf vegetable featuring thick,
flat, glossy blue-green leaves with thick stems and a small number of tiny, almost
vestigial flower heads similar to those of broccoli. As a group of Brassica oleracea, kai-
lan is one of the same species of plant as broccoli and kale. Its flavor is very similar to
that of broccoli, though not identical, being a bit sweeter.
Chinese kale is a vegetable crop with slender, bright green stalks ending in
slightly darker leafy greens, which are sometimes accompanied by clusters of tiny white
flower buds. It has a flavor comparable to that of broccoli raab and is used in Chinese
cuisine, typically chopped in stir-fry dishes. Chinese broccoli is also known as Chinese
kale, flowering kale (English), kai-lan (Cantonese), gai-lan, jie-lan (Mandarin), cai -ro
(Vietnamese), and kat-na (Khmer). This crop resembles the more familiar broccoli with
a longer stem and very small head. Unlike many other Asian greens in the Brassica
family, this crop has a thick stem like cole crops that originated in the Mediterranean,
such as broccoli, cauliflower, and Brussels sprouts ("cole" means stem in old English). It
is believed that early Portuguese explorers brought cabbage to Asia and through
generations of selections, it has developed into Chinese broccoli ( Anon, 2006).
Yield Losses Due to Weeds
A study conducted by Anderson (1983) showed that weeds reduced yield by as
much as 27% compared to weed-free potato plants. No yield reduction was noted on
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
4
potatoes kept weed-free for the first four weeks after planting. In a similar study, King
(1985) found that Agropyron replus reduces potato yield by 52% below weeded plants.
In carrot, yield reduction reached 30% while up to 60% was observed in onions and beets
(Stanbolts and Holm, 1956 cf. Crafts and Robbins, 1962). Subramanian (1981) reported
that weeds decrease soybean yields by reducing pod, branch, leaf and flower number per
plant, seed number per pod, and plant dry weight. Bongolan and Wells (1981) reported
yield losses due to uncontrolled weed growth in soybeans planted after transplanted rice
were negligible in most tropical countries contradicting the report of Anon. (1980) that
mungbean yields were markedly reduced during the dry season under the same tropical
conditions. Bleasedale (1960) mentioned that the presence of weed significantly reduced
the weight of tops, total roots and marketability of carrots. He further stated that the time
of weeding is important and that delaying the first weeding significantly reduced yield of
marketable crops. Because weeds causes the heaviest yield losses, cultivation should be
done when weeds are breaking through the soil surface since they are not yet well
established (Guantes, 1980).
Crop-Weed Competition
Most injurious to crop caused by weeds occur during the first 25-30% of their life
duration which is describe as the critical period of weed competition and the most
appropriate time to apply weed control measures (Paller and Soriano, 1977). They added
that emergence of weed after this period no longer reduces crop yield because the crop
had already develop extensive root system and considerable foliage to compete favorably
with the late emerging weeds. But Moody and Paller (1976) reported that in general, the
critical period of weed competition of most crops is in the 25-55% of their life cycle.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
5
They added that weeds growing in the place where they are not wanted inflict
considerable damage like competing with crops for water, nutrients and space causing
yield reduction. Chapman (1976) also stated that weeds grow taller and shade the crop to
such extent that photosynthetic capacity of the crop is drastically reduced.
Thompson and Kelly (1957 cf. Serra, 1981) stated that weeding should be done
when weeds are still small for it requires less labor and effectively checks competition
between the crop and the weeds. Destroying weeds is important before they seriously
compete with the crop for growth factors.
Crafts and Robbins (1962) claimed that plants differ in their competing ability.
The characteristics that enable species to be successful in competition are high
germination of seeds under adverse conditions and the rapid development of an extensive
root system having both surface and deep roots.
Weed Control
Villareal and Wallace (1969) suggested that weed control should be started on
land preparation and application of herbicide be applied to the surface and incorporated
immediately through disking. Knott and Deanon (1969) also suggested that good control
of weed is important for satisfactory crop production and that cultivation be started as the
seedlings appear in order to check weed growth.
Effective weed control should include a combination of practices designed to
suppress weeds during the entire year (Stall, n.d.). The same author stated some of the
management practices include crop rotation, cover cropping, cultivation flooding and
mulching.
Anon. (2007) stated that it is important to control weeds while they are small and
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
6
before they get out of control. Most weeds can be controlled and kept from becoming
serious problems in the garden. These methods of control include hand-pulling,
cultivation, mulching and use of chemicals.
Anon. (1975) suggested that hand weeding is preferred during the growth period
of the plant and that weeding should be done prior to fertilizer application.
For effective weed control as stated by Bawang (2006), control measures should
be directed to plant organs responsible for reproduction. For annuals, direct control
measure may be done by preventing the weeds from producing seeds. In other words, the
time to control the weed is at the early vegetative stage. Also, try to deplete weed seed
reserves in the soil by thorough land preparation. For perennials, effective control may
be done by destroying the underground vegetative propagules. The same author also
stated that control measure should be done until such time that the crop can take good
care of itself and combination of two control measures is better than one.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
MATERIALS AND METHODS
Materials
The materials used were Chinese Kale (‘Kai-lan’) seeds, sticks with identifying
marks, insecticides, fungicides, fertilizers, weighing scale, 1 m x 1 m quadrant, and
measuring stick.
Methods
Experimental design and treatments. The experiment was laid out in randomized
complete block design (RCBD) with four replications. The treatments were as follows:
Code
Description
T1
Weed-free from transplanting up to harvesting
T2
Weed-free for 10 days after transplanting then unweeded
up to harvesting
T3
Weed-free for 20 days after transplanting then unweeded
up to harvesting
T4
Weed-free for 30 days after transplanting then unweeded
up to harvesting
T5
Unweeded from transplanting up to harvesting
Seedling production. A plot measuring 1 m x 10 m was be thoroughly prepared.
Furrows across the plot were made for the seeds to be sown thinly, covered with soil
followed by watering.
Land preparation and fertilizer application. An area of 120 m2 was thoroughly
prepared and divided into experimental plots with a dimension of 1 m x 5 m. The plots
were leveled and holes were made 20 cm between hills and rows. The total amount of
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
inorganic fertilizer (80-80-80 kg N-P2O5-K2O/ha) and chicken manure (3.0t/ha) were
applied in the prepared holes and immediately soil incorporated before transplanting.
Transplanting. Three week-old seedlings were transplanted in the holes followed
immediately by watering. There were three rows per raised beds.
Other cultural management practices. Except for the imposition of the various
treatments, all the cultural management practices such as insect pests and diseases control
and irrigation were strictly followed.
Harvesting. All plants were hand harvested using a sharp knife at the marketable
stage and was based when the plants show opening of the first vestigial flower.
Data gathering. The data gathered and subjected for variance analysis and mean
separation test by Duncan’s multiple range test (DMRT) were the following:
1. Weeding time (hours). The time duration of weeding in each treatment was
recorded.
2. Weed identification and count. The weeds growing in association with the
crop were identified and counted in a 1 m x 1 m quadrant after harvest.
3. Plant growth increment (cm/week). The initial height of four randomly
selected seedlings was taken before transplanting and at 7-day intervals and at harvest.
4. Percentage survival. The number of plants harvested was counted and the
percentage of survival was computed using the formula:
Number of harvested plants/plot
Survival (%) = ───────────────────────── x 100
Total number of plants/plot
5. Average marketable plant weight (g). This was taken by using the formula:
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
9
Average (g) = Total marketable plant weight (kg/plot) ¸ Number of marketable
plants
6. Marketable yield (kg/plot). The weight of marketable plants without any
defects was taken at harvest.
7. Non-marketable yield (kg/plot). The weight of non-marketable plants such as
excessively small and rotten plants was taken at harvest.
8. Total yield (kg/plot). This was obtained by taking all the weight of harvested
plants per plot.
9. Computed marketable yield (t/ha). This was computed using the formula:
Computed yield (t/ha) = Marketable yield (kg/plot) x 2
where: 2 is a factor to convert the marketable yield (kg/plot) to t/ha based on the
experimental plot size used.
10. Others. The following data will also be taken but will not be subjected to
variance analysis.
a. Benefit cost ratio (BCR). This will be obtained by recording the man-
days/ha of weeding and BCR will be computed by using the formula:
BCR = Benefit-Cost
───────── + 1
Cost
b. Documentation of the study through pictures.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
RESULTS AND DISCUSSION
Weeding Time
Table 1 shows the time of weeding recorded from the various weed control
treatments after transplanting. Results showed that plants weed-free from transplanting
up to harvesting and weed-free for 30 days after transplanting (DAT) were comparable
but considerably required longer duration of weeding than the other treatments.
Identified Weed Species and Population
Small flower galinsoga (Galinsoga parviflora Cav.) was identified as the
predominantly weed species growing in association with the crop while the minor were
goosegrass (Eleusine indica L.) and crabgrass (Digitaria sanguinalis L.) as presented in
Table 2. The population of G. parviflora at harvest was significantly higher in the
unweeded plots than the rest of the treatments. Plots weeded 10, 20 and 30 DAT have
comparable population.
Table 1. Weeding time
═══════════════════════════════════════════════════════════
════
WEEDING
MEAN
DURATION (days)
(hr)
───────────────────────────────────────────────────────────
────
Weed-free
0.91a
Weed-free for 10 DAT
0.08c
Weed-free for 20 DAT
0.34b
Weed-free for 30 DAT
0.77a
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
Unweeded
0.00d
═══════════════════════════════════════════════════════════
════
Means with a common letter are not significantly different at 5% by DMRT
Table 2. Identified weed species and population
═══════════════════════════════════════════════════════════
════
WEEDING
WEED SPECIES
DURATION (days)
───────────────────────────────────
G. parviflora E. indica D. sanguinalis
───────────────────────────────────────────────────────────
────
Weed-free
0.0c
0.0b 0.0c
Weed-free for 10 DAT
213.25b
206.25a 148.75ab
Wed-free for 20 DAT
214.50b
192.25a 107.50ab
Weed-free for 30 DAT
213.00b
187.25a 88.50b
Unweeded
270.75a 208.25a 170.25a
═══════════════════════════════════════════════════════════
════
In a column, means a with common letter are not significantly different at 5% level by
DMRT
Growth Increment and Final Height
Table 3 shows that plant growth increment measured in one, two and three weeks
after transplanting were not significant. But on the fourth measurement, growth
increment was significantly higher in plants weed-free for 30 DAT compared to the rest
of the weeding durations. On the fifth and sixth measurements, weed-free plants for 30
DAT had markedly higher growth but comparable to weed-free and those weed-free for
20 DAT but were considerably higher than those plants weed-free for 10 DAT and
unweeded plots. On the other hand, the weed-free plants had the highest increment but
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
12
was comparable to weed-free plants for 20 and 30 DAT on the seventh measurement.
For the final height at harvest, weed-free plants markedly had the tallest however,
comparable with those plants at 30 DAT (Table 3). But the former was significantly
taller compared to the rest of the treatments.
Table 3. Weekly growth increment
═══════════════════════════════════════════════════════════
════
WEEDING
WEEKLY MEASUREMENT (cm/plant)
FINAL
DURATION (days) ───────── ────── ─────────────────── HEIGHT
1 2 3 4 5 6 7 (cm)
───────────────────────────────────────────────────────────
────
Weed-free
0.54a 1.08a 1.40a 3.75b 8.55a 8.90a 8.75a 40.25a
Weed-free for 10 DAT 0.48a 0.70a 1.39a 3.85b 4.08bc 6.23b 5.78bc 29.63c
Weed-free for 20 DAT 0.49a 0.65a 1.60a 4.13b 5.38abc 10.68a 7.90a 34.90b
Weed-free for 30 DAT 0.67a 0.85a 1.33a 6.10a 7.43ab 10.10a 7.45ab 37.75ab
Unweeded
0.41a 0.60a 0.55a 3.23b 3.45c 4.57c 4.55c 23.30d
═══════════════════════════════════════════════════════════
════
In a column, means a with common letter are not significantly different at 5% level by
DMRT
Crop Survival
Plants kept weed-free from transplanting up harvesting had significantly higher
percentage survival than the other of the treatments but comparable to 20 and 30 DAT
(Table 4). Plants kept unweeded had the lowest percentage survival however,
comparable to 10 DAT.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
13
Average Weight of Marketable, Non-marketable
and Marketable Yields
Table 5 shows the average weight of marketable and non-marketable and
marketable yields. The average marketable weight per plant was significantly higher in
plots kept weed-free but was comparable to those kept weed-free for 20 and 30 DAT.
However, the former was significantly higher than those kept weed-free for 10 DAT and
unweeded plants. In terms of the non-marketable yield per plot, there were significant
differences among the treatments. Plants kept weed-free and those weed-free for 20 and
30 DAT were comparable with each other but these treatments produce higher non-
marketable yield than those at 20 Table 4. Crop survival
═══════════════════════════════════════════════════════════
════
WEEDING
MEAN
DURATION (days)
(%)
───────────────────────────────────────────────────────────
────
Weed-free
68.00a
Weed-free for 10 DAT
37.75bc
Weed-free for 20 DAT
57.50ab
Weed-free for 30 DAT
67.75a
Unweeded
31.00c
═══════════════════════════════════════════════════════════
════
Means with a common letter are not significantly different at 5% by DMRT
Table 5. Average marketable weight, non-marketable, and marketable yields
═══════════════════════════════════════════════════════════
════
WEEDING
AVERAGE
YIELDS (kg/plot)
DURATION
WEIGHT
─────────
───────────────────
(days)
(g/plant)
Non-marketable
Marketable
───────────────────────────────────────────────────────────
────
Weed-free
121.45a
2.35a
3.80a
Weed-free for 10 DAT 53.94b
0.75b
1.35c
Weed-free for 20 DAT 100.65ab
2.15a
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
14
2.40b
Weed-free for 30 DAT 117.092a
2.25a
3.95a
Unweeded
54.69b
0.55b
0.70c
═══════════════════════════════════════════════════════════
════
In a column, means a with common letter are not significantly different at 5% level by
DMRT
DAT and unweeded plots. The marketable yields per plot were significantly higher in the
weed-free plants and those weed-free for 30 DAT than those weeded for 10 and 20 DAT
and the unweeded plants.
Total and Computed Yields, Yield
Reduction, and Benefit:Cost Ratio
The total and computed yields of plants kept weed-free up to harvesting was
markedly the highest compared to the rest of the treatments except for those plants kept
weed-free for 30 DAT as presented in Table 6. Yield reduction ranges from 5.69 to
82.11% for plants kept weed-free for 30 DAT and those unweeded. In terms of
benefit:cost ratio, the highest was realized from plants kept weed-free for 30 DAT
followed by those kept weed-free up to harvesting.
Pictorial Documentation
Figs. 1 and 2 show the overview of the experiment before harvest and the
harvested plants, respectively.
The weeding time (Table 1) required to remove G. parviflora, E. indica, D.
sanguinalis identified and counted weeds (Table 2) growing in association with the crop
increases with longer durations of weed control. This is attributed to more weeds with
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
15
well-
Table 6. Total and computed marketable yields, yield reduction and benefit:cost ratio
═══════════════════════════════════════════════════════════
════
WEEDING
TOTAL YIELD
COMPUTED
BENEFIT:
DURATION
YIELD REDUCTION YIELD COST
(days)
(kg/plot) (%)
(t/ha)
RATIO
───────────────────────────────────────────────────────────
────
Weed-free
6.15a
-
7.45a
31.73
Weed-free for 10 DAT 2.10c
65.85
2.70bc 16.63
Weed-free for 20 DAT 4.05b
34.14
4.30b
23.03
Weed-free for 30 DAT 5.80a
5.69
7.90a
34.86
Unweeded
1.10c
82.11
1.40c
-
═══════════════════════════════════════════════════════════
════
In a column, means a with common letter are not significantly different at 5% level by
DMRT established root system when allowed to grow for a longer duration making them
harder to uproot than at earlier period supporting the statement of Anderson (1983) that
weeding tool 20-30% of farmers’ time and the it accounted for only 2.0 to 6.0% of that
production cost.
Allowing crop-weed mixtures after 10 to 30 days from transplanting (DAT) did
not result to a significant increase in plant growth increments (Table 3) but significantly
affected four to seven weeks after transplanting. Results suggest that transplanted
Chinese kale crop can effectively compete with the weeds because they were given a
head-start.
Manifestation of crop-weed competition were noticeable as the association was
prolonged causing a remarkable reduction in crop survival, average plant weight,
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
18
marketable and total yields resulting to a tremendous yield reductions (Tables 4-6).
These repercussions indicated that the crop lost its competitiveness with the weeds for
growth factors essential for growth and development (Villareal and Wallace, 1969;
Anderson, 1983). Moody (1993) also stated that any weed growing in association with
the crop will reduce the vegetative dry matter potential of the crop. In this study,
allowing crop-weed mixtures from transplanting to harvesting resulted to 82.11% yield
reduction (Table 6) supporting several reports that crop-weed mixture reduced yields by
as much as 30% in carrot, 60% in onions and beets (Stanbold and Holms, 1956 cf. Crafts
and Robbins, 1962), and 52% in potato (King, 1985). Subramanian (1981) also reported
that weeds decrease soybean yields by reducing pod, branch, leaf, and flower numbers
per plant, seed number per pod, and plant dry weight. Bleasedale (1960) mentioned that
the presence of weed significantly reduced the weight of tops, total roots and
marketability of carrots. In lettuce, a maximum yield was obtained with a single weeding
25 days after transplanting (Cardona, 1977). Also, increasing the time that weeds
remained in plots before removal, the greater the reduction in garlic yield and quality
(Qasem, 1996). Yield reductions ranging from 6.12 to 88.57% was also reported by Diaz
(1998) in lettuce crop while 22.48-70.33% in cabbage crop (Atiwon, 1999).
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary
The study was conducted at the Balili Experimental Station, Benguet State
University, La Trinidad, Benguet from June to July 2007 to determine the effects of
weeding durations on the growth and yield, to establish the best time of weeding, and to
assess the economics of the various weeding durations in Chinese kale production.
Results showed that plants weed-free from transplanting up to harvesting and
weed-free for 30 days after transplanting (DAT) were comparable but considerably
required longer duration of weeding than the other treatments.
Small flower galinsoga (Galinsoga parviflora Cav.) was identified as the
predominantly weed species growing in association with the crop while the minor were
goosegrass (Eleusine indica L.) and crabgrass (Digitaria sanguinalis L.). The
population of G. parviflora at harvest was significantly higher in the unweeded plots than
the rest of the treatments. Plots weeded for 10, 20 and 30 DAT have comparable
population.
Plant growth increment measured in one, two and three weeks after transplanting
were not significant. But on the fourth measurement, growth increment was significantly
higher in plants weed-free for 30 DAT compared to the rest of the weeding durations. On
the fifth and sixth measurements, weed-free plants for 30 DAT had markedly higher
growth but comparable to weed-free and those weed-free for 20 DAT but were
considerably higher than those plants weed-free for 10 DAT and unweeded plots. On the
other hand, the weed-free plants had the highest increment but was comparable to weed-
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
20
free plants for 20 and 30 DAT on the seventh measurement. For the final height at
harvest, weed-free plants markedly had the tallest however, comparable with those plants
at 30 DAT. But the former was significantly taller compared to the rest of the treatments.
The average marketable weight per plant was significantly higher in plots kept
weed-free but was comparable to those kept weed-free for 20 and 30 DAT. However, the
former was significantly higher than those kept weed-free for 10 DAT and unweeded
plants. In terms of the non-marketable yield per plot, there were significant differences
among the treatments. Plants kept weed-free and those weed-free for 20 and 30 DAT
were comparable with each other but these treatments produce higher non-marketable
yield than those weed-free for 20 DAT and unweeded plots. The marketable yields per
plot were significantly higher in the weed-free plants and those weed-free for 30 DAT
than those weeded for 10 and 20 DAT and the unweeded plants. The total and computed
yields of plants kept weed-free up to harvesting was markedly the highest compared to
the rest of the treatments except for those plants kept weed-free for 30 DAT. Yield
reduction ranges from 5.69 to 82.11% for plants kept weed-free for 30 DAT and those
unweeded. In terms of benefit:cost ratio, the highest was realized from plants kept weed-
free for 30 DAT followed by those kept weed-free up to harvesting.
Conclusion
Based from the results of the study, plants kept weed-free and those weed-free for
30 days after transplanting had the highest yield and profitability. In conclusion, keeping
the plants weed-free for 30 days after transplanting could be done to reduce labor cost in
controlling in weeds for Chinese kale production.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
21
Recommendation
From the preceding results and discussions, it is recommended to keep the plants
weed-free for at least 30 days after transplanting. It is further recommended that a similar
study will be conducted on Chinese kale production during the dry cropping season.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
LITERATURE CITED
ANDERSON, W.P. 1983. Weed Science: Principles. St. Paul: West Publ. p. 655.
ANONYMOUS. 2006. Weed management in vegetable crops. IPM- University of
California.
_____. 2006. Chinese Broccoli. Wikipedia. The Free encyclop.
_____. 1975. The Philippine Recommends for Vegetable Crops. PCAR Series. No. 3:37.
_____. 1980. The effect of duration of weed competition on the growth and yield of Mungbean. Particip
ATIWON, A.B. 1999. Duration of crop-weed competition in transplanted cabbage. BS Thesis. BSU, L
BAWANG, F. T. 2006. Production and Postharvest Technologies of Vegetables in the
Mid-Elevation and High Altitude Tropics. Benguet State University, La Trinidad,
Benguet. Philippines. P. 56.
BLEASEDALE, J.K.A. 1960. Studies of Plant Competition in the Biology of Weeds. New York: McGr
BONGOLAN, F. and G.F. WELLS. 1981. Weed Control in upland crops in the
Philippine. In Proc. 6th Asian-Pacific Weed Sci. Soc. Conf. Bangalore, India.
Pp. 11-16
CARDONA, P.F. 1977. Weed competition in lettuce. Institute of Columbian
Agriculture, Bogota, Columbia 12(4):407-420.
CHAPMAN, S.R. 1976. Crop Production. San Francisco:W.H. Freeman Co. Pp. 165-193.
CRAFTS, A.S. and W. ROBBINS. 1976. Weed Control. New York: McGraw Hill Book Co. P. 96.
DIAZ, A.Y. 1998. Growth and yield of head lettuce as affected by the duration of weed competition. B
GUANTES, M.M. 1980. Weed control studies in sunflower. Phil. J. Weed Sci. 5:7-15.
KING, G.R. 1985. Farmer’s Weed Control Handbook. St. Louis, Missouri: Doanne Publ. P. 241.
KNOTT J.E. and J.R. DEANON, Jr. 1969. Vegetable Production in Southeast Asian. UPCA, Los Baño
MOODY, K. 1993. Weed Control in Rice using Non-chemical Method. NCPC-UPLB, College, Los Bañ
______ and E.C. PALLER, Jr. 1976. Manual in Weed Science Training Course. NCPC-UPLB, College
PALLER, E.C. and J. M. SORIANO. 1997. Weed Control in vegetable fields. In
Vegetable
Production (O.K. Bautista and R.C. Mabesa). Los
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
23
Baños: UPCA. Pp. 66-68.
QASEM, J.R. 1996. Weed competition in garlic. J. Hort. Sci. 71:41-48.
STALL, W. M. and J. A. DUSKY. n.d. Weed control in leafy vegetables. Univ. Of Florida, Gainesville
SUBRAMANIAN, S. 1981. All About Weed Control. New Delhi: Kalyani Pub. P. 315
THOMPSON, H.C. and W.C. KELLY. 1957. Vegetable Crops. New York: McGraw Hill Book Co. P.
VILLAREAL, R.A. and D. WALLACE. 1969. Vegetable Training Manual. Los Baños,
Laguna. P. 80.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
APPENDICES
Appendix Table 1. Weeding time (hrs)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
1.13
0.97 0.73 0.78
3.61 0.91
T2
0.10
0.08 0.07 0.07
0.32 0.08
T3
0.53
0.33 0.32 0.18
1.36 0.34
T4
1.00
0.08 0.68 0.58
3.06 0.77
T5
0.00
0.00 0.00 0.00
0.00 0.00
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
0.154 0.051
Treatment
4
2.601 0.650
72.59**
3.26
5.41
Error
12
0.107 0.009
───────────────────────────────────────────────────────────
────
Total
19
2.063
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 22.67%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
25
Appendix Table 2. Growth increment one week after transplanting (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
0.66
0.50 0.70 0.30
2.16 0.54
T2
0.60
0.30 0.40 0.60
1.90 0.48
T3
0.80
0.40 0.46 0.30
1.96 0.49
T4
1.10
0.78 0.30 0.50
2.68 0.67
T5
0.34
0.60 0.20 0.50
1.64 0.41
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
0.252 0.084
Treatment
4
0.152 0.038
0.89ns
3.26
5.41
Error
12
0.512 0.043
───────────────────────────────────────────────────────────
────
Total
19
0.915
═══════════════════════════════════════════════════════════
════
ns = Not significant
Coefficient of variation = 39.94%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
26
Appendix Table 3. Growth increment two week after transplanting (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
1.1
1.4
1.3 0.5
4.30 1.08
T2
1.0
0.8
0.5 0.5
2.80 0.70
T3
0.8
0.7
0.6 0.5
2.60 0.65
T4
0.8
1.0
0.5 1.1
3.40 0.85
T5
0.8
0.6
0.5 0.5
2.40 0.60
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
0.322 0.107
Treatment
4
0.590 0.147
2.66ns
3.26
5.41
Error
12
0.666 0.055
───────────────────────────────────────────────────────────
────
Total
19
1.577
═══════════════════════════════════════════════════════════
════
ns = Not significant
Coefficient of variation = 30.40%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
27
Appendix Table 4. Growth increment three weeks after transplanting (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
1.50
1.40 0.80 1.90
5.60 1.40
T2
2.50
0.90 1.10 1.05
5.55 1.39
T3
1.90
1.70 1.00 1.80
6.40 1.60
T4
1.40
1.20 1.10 1.60
5.30 1.33
T5
0.70
0.40 0.60 0.50
2.20 0.55
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
1.313 0.438
Treatment
4
2.638 0.659
4.72*
3.26
5.41
Error
12
1.676 0.140
───────────────────────────────────────────────────────────
────
Total
19
5.627
═══════════════════════════════════════════════════════════
════
* = Significant
Coefficient of variation = 29.84%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
28
Appendix Table 5. Growth increment four weeks after transplanting (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
3.8
3.5
4.6 3.1
15.00
3.75
T2
3.0
4.5
4.6 3.3
15.40
3.85
T3
2.7
3.3
5.4 5.1
16.50
4.13
T4
3.7
7.3
5.7 7.7
24.40
6.10
T5
2.1
2.0
4.2 4.6
12.90
3.23
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
10.546 3.515
Treatment
4
19.563 4.891
4.35*
3.26
5.41
Error
12
13.489 1.124
───────────────────────────────────────────────────────────
────
Total
19
43.598
═══════════════════════════════════════════════════════════
════
* = Significant
Coefficient of variation = 25.18%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
29
Appendix Table 6. Growth increment five weeks after transplanting (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
6.4
10.1 13.7 4.0
34.20
8.55
T2
2.5
4.7 5.7 3.4
16.30
4.08
T3
4.4
4.0 5.5 7.6
21.50
5.38
T4
8.5
5.0 7.7 8.5
29.70
7.43
T5
2.7
2.0 5.4 3.7
13.80
3.45
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
22.933 7.644
Treatment
4
75.515 18.879 3.78*
3.26
5.41
Error
12
59.889 4.991
───────────────────────────────────────────────────────────
────
Total
19
158.337
═══════════════════════════════════════════════════════════
════
* = Significant
Coefficient of variation = 38.68%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
30
Appendix Table 7. Growth increment six weeks after transplanting (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
9.1
8.0 12.5 6.0
35.60
8.90
T2
4.6
9.8 4.6 5.9
24.90
6.23
T3
10.1
12.7 12.0 7.9
42.70
10.68
T4
10.0
10.6 10.8 9.0
40.40
10.10
T5
4.6
4.2 5.6 3.9
18.30
4.57
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
22.657 7.552
Treatment
4
108.847 27.212 9.27**
3.26
5.41
Error
12
35.225 2.935
───────────────────────────────────────────────────────────
────
Total
19
166.730
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 21.16%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
31
Appendix Table 8. Growth increment seven weeks after transplanting (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
8.4
8.6
8.7 9.3
35.00
8.75
T2
5.0
5.8
7.5 4.8
23.10
5.78
T3
8.6
9.9
6.1 7.0
31.60
7.90
T4
6.4
9.7
5.4 8.3
29.80
7.45
T5
4.0
4.7
4.8 4.7
18.20
4.55
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
5.237 1.746
Treatment
4
46.048 11.512 6.98**
3.26
5.41
Error
12
19.780 1.648
───────────────────────────────────────────────────────────
────
Total
19
71.065
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 18.65%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
32
Appendix Table 9. Final plant height (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
33.4
45.6 42.2 39.8
161.00
40.25
T2
24.5
31.6 37.8 24.6
118.50
29.63
T3
33.6
36.4 34.6 35.0
139.60
34.90
T4
36.2
38.8 36.2 39.8
151.00
37.75
T5
17.2
28.6 25.6 21.8
93.20
23.30
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
160.649 53.550
Treatment
4
736.318 184.079 17.24** 3.26
5.41
Error
12
128.138 10.678
───────────────────────────────────────────────────────────
────
Total
19
1025.105
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 9.85%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
33
Appendix Table 10. Crop survival (%)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
56.0
51.0 80.0 85.0
272.0
68.00
T2
41.0
40.0 53.0 17.0
151.0
37.75
T3
41.0
68.0 80.0 41.0
230.0
57.50
T4
52.0
53.0 79.0 87.0
271.0
67.75
T5
36.0
31.0 45.0 12.0
124.0
31.00
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
1536.40 512.133
Treatment
4
4710.30 1177.575 5.21*
3.26
5.41
Error
12
2714.10 226.175
───────────────────────────────────────────────────────────
────
Total
19
8960.80
═══════════════════════════════════════════════════════════
════
* = Significant
Coefficient of variation = 28.70%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
34
Appendix Table 11. Average marketable yield (g/plant)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
95.24 152.63 106.67 131.25 485.788
121.447
T2
64.52
9.33 65.00 76.92 215.766
53.941
T3
96.77 94.12 63.33 148.39 402.611
100.653
T4
102.56 165.00 108.74 95.38 471.680
117.920
T5
66.67 78.26 29.41 44.44 218.778
54.694
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
2214.321 738.107
Treatment
4
17713.015 4428.254 4.95*
3.26
5.41
Error
12
10729.194 894.100
───────────────────────────────────────────────────────────
────
Total
19
30656.530
═══════════════════════════════════════════════════════════
════
* = Significant
Coefficient of variation = 33.32%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
35
Appendix Table 12. Non-marketable yield (kg/plot)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
0.8
2.2
3.0 3.4
9.40 2.35
T2
0.8
1.0
1.0 0.2
3.00 0.75
T3
1.0
3.8
1.8 2.0
8.60 2.15
T4
0.6
2.6
3.4 2.4
9.00 2.25
T5
0.8
0.8
0.4 0.2
2.20 0.55
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
4.870 1.623
Treatment
4
12.448 3.112
4.58*
3.26
5.41
Error
12
8.160 0.680
───────────────────────────────────────────────────────────
────
Total
19 25.478
═══════════════════════════════════════════════════════════
════
* = Significant
Coefficient of variation = 51.22%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
36
Appendix Table 13. Marketable yield (kg/plot)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
3.2
3.6
3.4 5.0
15.20
3.80
T2
1.2
1.8
1.6 0.8
5.40
1.35
T3
2.0
3.0
2.0 2.6
9.60
2.40
T4
3.4
4.0
3.8 4.6
15.80
3.95
T5
1.0
1.0
0.6 0.2
2.80
0.70
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
1.008 0.336
Treatment
4
33.388 8.347
28.68** 3.26
5.41
Error
12
3.492 0.291
───────────────────────────────────────────────────────────
────
Total
19
37.888
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 22.11%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
37
Appendix Table 14. Total yield (kg/plot)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
4.0
5.8
6.4 8.4
24.60
6.15
T2
2.0
2.8
2.6 1.0
8.40
2.10
T3
3.0
4.8
3.8 4.6
16.20
4.05
T4
4.0
6.6
6.4 6.2
23.20
5.80
T5
1.8
1.2
1.0 0.4
4.40
1.10
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
5.264 1.755
Treatment
4
79.028 19.757 16.94** 3.26
5.41
Error
12
13.996 1.166
───────────────────────────────────────────────────────────
────
Total
19
98.288
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 28.12%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
38
Appendix Table 15. Computed yield (t/ha)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
6.4
7.2
6.2 10.0
29.80
7.45
T2
2.4
3.6
3.2 1.6
10.80
2.70
T3
4.0
6.0
4.0 3.2
17.20
4.30
T4
6.8
8.0
7.6 9.2
31.60
7.90
T5
2.0
2.0
1.2 0.4
5.60
1.40
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
3.35 1.117
Treatment
4
131.36 32.840 22.81** 3.26
5.41
Error
12
17.28 1.440
───────────────────────────────────────────────────────────
────
Total
19
151.99
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 25.26%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
39
Appendix Table 16. Population of Galisoga parviflora (1 m x 1 m quadrant)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
0.0
0.0 0.0 0.0
0.0
0.00
T2
223.0 211.0 218.0 201.0
853.0
213.25
T3
231.0 216.0 221.0 190.0
858.0
214.50
T4
211.0 236.0 209.0 196.0
852.0
213.00
T5
286.0 255.0 269.0 273.0
1083.0
270.75
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
857.00 285.667
Treatment
4
175975.70 43993.925 318.12** 3.26
5.41
Error
12
1659.50 138.292
───────────────────────────────────────────────────────────
────
Total
19
178492.20
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 6.45%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
40
Appendix Table 17. Population of Eleucine indica (1 m x 1 m quadrant)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
0.0
0.0 0.0 0.0
0.0
0.00
T2
205.0 196.0 213.0 211.0
825.0
206.25
T3
180.0 207.0 159.0 223.0
769.0
192.25
T4
154.0 194.0 186.0 215.0
749.0
187.25
T5
239.0 208.0 197.0 189.0
833.0
208.25
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
766.80 255.600
Treatment
4
127370.20 31842.550 73.59** 3.26
5.41
Error
12
5192.20 432.683
───────────────────────────────────────────────────────────
────
Total
19
133329.20
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 13.10%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
41
Appendix Table 18. Population of Digitaria sanguinalis (1 m x 1 m quadrant)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
0.0
0.0 0.0 0.0
0.0
0.00
T2
206.0
86.0 211.0 92.0
595.0
148.75
T3
91.0 115.0 127.0 97.0
430.0
107.50
T4
87.0 91.0 103.0 73.0
354.0
88.50
T5
255.0 211.0 98.0 117.0
681.0
170.25
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
6918.40 2306.133
Treatment
4
69820.50 17455.125 8.19**
3.26
5.41
Error
12
25569.10 2130.758
───────────────────────────────────────────────────────────
────
Total
19
102308.00
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 44.82%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
BALICDANG, JANET S. OCTOBER 2007. Growth and Yield of Chinese Kale
(Brassica oleracea var. alboglabra) as Affected by Duration of Weed Control. Benguet
State University, La Trinidad, Benguet.
Adviser: Pepe E. Toledo, PhD
ABSTRACT
The study was conducted at the Balili Experimental Station, Benguet State
University, La Trinidad, Benguet from June to July 2007 to determine the effects of
weeding durations on the growth and yield, to establish the best time of weeding, and to
assess the economics of the various weeding durations in Chinese kale production.
Results showed that plants weed-free from transplanting up to harvesting and
weed-free for 30 days after transplanting (DAT) were comparable but considerably
required longer duration of weeding than the other treatments.
Small flower galinsoga (Galinsoga parviflora Cav.) was identified as the
predominantly weed species growing in association with the crop while the minor were
goosegrass (Eleusine indica L.) and crabgrass (Digitaria sanguinalis L.). The
population of G. parviflora at harvest was significantly higher in the unweeded plots than
the rest of the treatments.
Plant growth increment measured in one, two and three weeks after transplanting
were not significant. But on the fourth measurement, growth increment was significantly
higher in plants weed-free for 30 DAT. On the fifth and sixth measurements, weed-free
plants for 30 DAT had markedly higher growth comparable to weed-free and those weed-
free for 20 DAT but were considerably higher than those plants weed-free for 10 DAT
and unweeded plots. Weed-free plants had the highest growth increment on the seventh
measurement. For the final height at harvest, weed-free plants markedly had the tallest
comparable with those plants at 30 DAT.
Plants kept weed-free and plants weeded for 30 DA T significantly produced
higher average marketable weight per plant, marketable, total, computed yields, and
benefit:cost ratio. Yield reduction ranges from 5.69 to 82.11%.
ii
TABLE OF CONTENTS
Page
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
i
Abstract………... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
i
Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
iii
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
REVIEW OF LITERATURE
Description of the Crop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
Yield Losses Due to Weeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
Crop-Weed Competition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
Weed Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
MATERIALS AND METHODS
Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
RESULTS AND DISCUSSION
Weeding Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10
Identified Weed Species and Population . . . . . . . . . . . . . . . . . . . . . . . .
10
Growth Increment and Final Height . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
Crop Survival . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12
Average Weight, Non-marketable and Marketable Yields . . . . . . . . . .
12
Total and Computed Yields and Benefit:Cost Ratio . . . . . . . . . . . . . . .
14
iii
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20
Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21
LITERATURE CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22
APPENDICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24
iv
INTRODUCTION
Vegetable production is a major industry in the highlands where majority of the
people in the Cordillera are engaged because they gain profit from producing vegetable
crops and the climatic conditions are favorable for their growth and development.
Chinese kale is an introduced crop in the Cordilleras. It offers benefits like a
source of income and one of the leafy vegetables with the best eating quality. However,
in growing vegetable crops, factors like weed occurrence should be considered. Weeds
compete with crop plants for sunlight, water, nutrients and space and their growth must
be limited to obtain a good yield of any food crop. Weed management strategies should
be employed to limit the deleterious effects in growing vegetables crops. If weeds are
able to utilize a sufficient amount of some growth factors to the detriment of the crop, the
results can be, and most often is, an adverse effect on crop yield in terms of quality and
volume. Therefore, it is important that weeds are controlled to prevent their competition
with the vegetable crop grown.
The presence of weeds is a serious garden problem. They rob vegetable crops of
sunlight, water and nutrients. They also provide hiding places for insects and serve as a
source of crop diseases.
The existence of weeds in crop production is one major problem of vegetable
growers. Villareal and Wallace (1969) stated that many adapted weed species are
identified in the farmers’ fields that caused losses due to competition for light, mineral
nutrients, space and water. They also harbor insect pests and diseases that impair plant
growth and development resulting to poor and low yield.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
2
To attain satisfactory crop growth, development and good yield, weed control
should be done at the earliest stage of crop growth during the cropping season. Thus, this
study is conceptualized.
The study was conducted at the Balili Experimental Station, Benguet State
University, La Trinidad, Benguet from June to July 2007 to determine the effects of
weeding durations on the growth and yield, to establish the best time of weeding, and to
assess the economics of the various weeding durations in Chinese kale production.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
REVIEW OF LITERATURE
Description of the Crop
Chinese broccoli or Chinese kale, is a slightly bitter leaf vegetable featuring thick,
flat, glossy blue-green leaves with thick stems and a small number of tiny, almost
vestigial flower heads similar to those of broccoli. As a group of Brassica oleracea, kai-
lan is one of the same species of plant as broccoli and kale. Its flavor is very similar to
that of broccoli, though not identical, being a bit sweeter.
Chinese kale is a vegetable crop with slender, bright green stalks ending in
slightly darker leafy greens, which are sometimes accompanied by clusters of tiny white
flower buds. It has a flavor comparable to that of broccoli raab and is used in Chinese
cuisine, typically chopped in stir-fry dishes. Chinese broccoli is also known as Chinese
kale, flowering kale (English), kai-lan (Cantonese), gai-lan, jie-lan (Mandarin), cai -ro
(Vietnamese), and kat-na (Khmer). This crop resembles the more familiar broccoli with
a longer stem and very small head. Unlike many other Asian greens in the Brassica
family, this crop has a thick stem like cole crops that originated in the Mediterranean,
such as broccoli, cauliflower, and Brussels sprouts ("cole" means stem in old English). It
is believed that early Portuguese explorers brought cabbage to Asia and through
generations of selections, it has developed into Chinese broccoli ( Anon, 2006).
Yield Losses Due to Weeds
A study conducted by Anderson (1983) showed that weeds reduced yield by as
much as 27% compared to weed-free potato plants. No yield reduction was noted on
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
4
potatoes kept weed-free for the first four weeks after planting. In a similar study, King
(1985) found that Agropyron replus reduces potato yield by 52% below weeded plants.
In carrot, yield reduction reached 30% while up to 60% was observed in onions and beets
(Stanbolts and Holm, 1956 cf. Crafts and Robbins, 1962). Subramanian (1981) reported
that weeds decrease soybean yields by reducing pod, branch, leaf and flower number per
plant, seed number per pod, and plant dry weight. Bongolan and Wells (1981) reported
yield losses due to uncontrolled weed growth in soybeans planted after transplanted rice
were negligible in most tropical countries contradicting the report of Anon. (1980) that
mungbean yields were markedly reduced during the dry season under the same tropical
conditions. Bleasedale (1960) mentioned that the presence of weed significantly reduced
the weight of tops, total roots and marketability of carrots. He further stated that the time
of weeding is important and that delaying the first weeding significantly reduced yield of
marketable crops. Because weeds causes the heaviest yield losses, cultivation should be
done when weeds are breaking through the soil surface since they are not yet well
established (Guantes, 1980).
Crop-Weed Competition
Most injurious to crop caused by weeds occur during the first 25-30% of their life
duration which is describe as the critical period of weed competition and the most
appropriate time to apply weed control measures (Paller and Soriano, 1977). They added
that emergence of weed after this period no longer reduces crop yield because the crop
had already develop extensive root system and considerable foliage to compete favorably
with the late emerging weeds. But Moody and Paller (1976) reported that in general, the
critical period of weed competition of most crops is in the 25-55% of their life cycle.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
5
They added that weeds growing in the place where they are not wanted inflict
considerable damage like competing with crops for water, nutrients and space causing
yield reduction. Chapman (1976) also stated that weeds grow taller and shade the crop to
such extent that photosynthetic capacity of the crop is drastically reduced.
Thompson and Kelly (1957 cf. Serra, 1981) stated that weeding should be done
when weeds are still small for it requires less labor and effectively checks competition
between the crop and the weeds. Destroying weeds is important before they seriously
compete with the crop for growth factors.
Crafts and Robbins (1962) claimed that plants differ in their competing ability.
The characteristics that enable species to be successful in competition are high
germination of seeds under adverse conditions and the rapid development of an extensive
root system having both surface and deep roots.
Weed Control
Villareal and Wallace (1969) suggested that weed control should be started on
land preparation and application of herbicide be applied to the surface and incorporated
immediately through disking. Knott and Deanon (1969) also suggested that good control
of weed is important for satisfactory crop production and that cultivation be started as the
seedlings appear in order to check weed growth.
Effective weed control should include a combination of practices designed to
suppress weeds during the entire year (Stall, n.d.). The same author stated some of the
management practices include crop rotation, cover cropping, cultivation flooding and
mulching.
Anon. (2007) stated that it is important to control weeds while they are small and
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
6
before they get out of control. Most weeds can be controlled and kept from becoming
serious problems in the garden. These methods of control include hand-pulling,
cultivation, mulching and use of chemicals.
Anon. (1975) suggested that hand weeding is preferred during the growth period
of the plant and that weeding should be done prior to fertilizer application.
For effective weed control as stated by Bawang (2006), control measures should
be directed to plant organs responsible for reproduction. For annuals, direct control
measure may be done by preventing the weeds from producing seeds. In other words, the
time to control the weed is at the early vegetative stage. Also, try to deplete weed seed
reserves in the soil by thorough land preparation. For perennials, effective control may
be done by destroying the underground vegetative propagules. The same author also
stated that control measure should be done until such time that the crop can take good
care of itself and combination of two control measures is better than one.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
MATERIALS AND METHODS
Materials
The materials used were Chinese Kale (‘Kai-lan’) seeds, sticks with identifying
marks, insecticides, fungicides, fertilizers, weighing scale, 1 m x 1 m quadrant, and
measuring stick.
Methods
Experimental design and treatments. The experiment was laid out in randomized
complete block design (RCBD) with four replications. The treatments were as follows:
Code
Description
T1
Weed-free from transplanting up to harvesting
T2
Weed-free for 10 days after transplanting then unweeded
up to harvesting
T3
Weed-free for 20 days after transplanting then unweeded
up to harvesting
T4
Weed-free for 30 days after transplanting then unweeded
up to harvesting
T5
Unweeded from transplanting up to harvesting
Seedling production. A plot measuring 1 m x 10 m was be thoroughly prepared.
Furrows across the plot were made for the seeds to be sown thinly, covered with soil
followed by watering.
Land preparation and fertilizer application. An area of 120 m2 was thoroughly
prepared and divided into experimental plots with a dimension of 1 m x 5 m. The plots
were leveled and holes were made 20 cm between hills and rows. The total amount of
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
inorganic fertilizer (80-80-80 kg N-P2O5-K2O/ha) and chicken manure (3.0t/ha) were
applied in the prepared holes and immediately soil incorporated before transplanting.
Transplanting. Three week-old seedlings were transplanted in the holes followed
immediately by watering. There were three rows per raised beds.
Other cultural management practices. Except for the imposition of the various
treatments, all the cultural management practices such as insect pests and diseases control
and irrigation were strictly followed.
Harvesting. All plants were hand harvested using a sharp knife at the marketable
stage and was based when the plants show opening of the first vestigial flower.
Data gathering. The data gathered and subjected for variance analysis and mean
separation test by Duncan’s multiple range test (DMRT) were the following:
1. Weeding time (hours). The time duration of weeding in each treatment was
recorded.
2. Weed identification and count. The weeds growing in association with the
crop were identified and counted in a 1 m x 1 m quadrant after harvest.
3. Plant growth increment (cm/week). The initial height of four randomly
selected seedlings was taken before transplanting and at 7-day intervals and at harvest.
4. Percentage survival. The number of plants harvested was counted and the
percentage of survival was computed using the formula:
Number of harvested plants/plot
Survival (%) = ───────────────────────── x 100
Total number of plants/plot
5. Average marketable plant weight (g). This was taken by using the formula:
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
9
Average (g) = Total marketable plant weight (kg/plot) ¸ Number of marketable
plants
6. Marketable yield (kg/plot). The weight of marketable plants without any
defects was taken at harvest.
7. Non-marketable yield (kg/plot). The weight of non-marketable plants such as
excessively small and rotten plants was taken at harvest.
8. Total yield (kg/plot). This was obtained by taking all the weight of harvested
plants per plot.
9. Computed marketable yield (t/ha). This was computed using the formula:
Computed yield (t/ha) = Marketable yield (kg/plot) x 2
where: 2 is a factor to convert the marketable yield (kg/plot) to t/ha based on the
experimental plot size used.
10. Others. The following data will also be taken but will not be subjected to
variance analysis.
a. Benefit cost ratio (BCR). This will be obtained by recording the man-
days/ha of weeding and BCR will be computed by using the formula:
BCR = Benefit-Cost
───────── + 1
Cost
b. Documentation of the study through pictures.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
RESULTS AND DISCUSSION
Weeding Time
Table 1 shows the time of weeding recorded from the various weed control
treatments after transplanting. Results showed that plants weed-free from transplanting
up to harvesting and weed-free for 30 days after transplanting (DAT) were comparable
but considerably required longer duration of weeding than the other treatments.
Identified Weed Species and Population
Small flower galinsoga (Galinsoga parviflora Cav.) was identified as the
predominantly weed species growing in association with the crop while the minor were
goosegrass (Eleusine indica L.) and crabgrass (Digitaria sanguinalis L.) as presented in
Table 2. The population of G. parviflora at harvest was significantly higher in the
unweeded plots than the rest of the treatments. Plots weeded 10, 20 and 30 DAT have
comparable population.
Table 1. Weeding time
═══════════════════════════════════════════════════════════
════
WEEDING
MEAN
DURATION (days)
(hr)
───────────────────────────────────────────────────────────
────
Weed-free
0.91a
Weed-free for 10 DAT
0.08c
Weed-free for 20 DAT
0.34b
Weed-free for 30 DAT
0.77a
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
Unweeded
0.00d
═══════════════════════════════════════════════════════════
════
Means with a common letter are not significantly different at 5% by DMRT
Table 2. Identified weed species and population
═══════════════════════════════════════════════════════════
════
WEEDING
WEED SPECIES
DURATION (days)
───────────────────────────────────
G. parviflora E. indica D. sanguinalis
───────────────────────────────────────────────────────────
────
Weed-free
0.0c
0.0b 0.0c
Weed-free for 10 DAT
213.25b
206.25a 148.75ab
Wed-free for 20 DAT
214.50b
192.25a 107.50ab
Weed-free for 30 DAT
213.00b
187.25a 88.50b
Unweeded
270.75a 208.25a 170.25a
═══════════════════════════════════════════════════════════
════
In a column, means a with common letter are not significantly different at 5% level by
DMRT
Growth Increment and Final Height
Table 3 shows that plant growth increment measured in one, two and three weeks
after transplanting were not significant. But on the fourth measurement, growth
increment was significantly higher in plants weed-free for 30 DAT compared to the rest
of the weeding durations. On the fifth and sixth measurements, weed-free plants for 30
DAT had markedly higher growth but comparable to weed-free and those weed-free for
20 DAT but were considerably higher than those plants weed-free for 10 DAT and
unweeded plots. On the other hand, the weed-free plants had the highest increment but
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
12
was comparable to weed-free plants for 20 and 30 DAT on the seventh measurement.
For the final height at harvest, weed-free plants markedly had the tallest however,
comparable with those plants at 30 DAT (Table 3). But the former was significantly
taller compared to the rest of the treatments.
Table 3. Weekly growth increment
═══════════════════════════════════════════════════════════
════
WEEDING
WEEKLY MEASUREMENT (cm/plant)
FINAL
DURATION (days) ───────── ────── ─────────────────── HEIGHT
1 2 3 4 5 6 7 (cm)
───────────────────────────────────────────────────────────
────
Weed-free
0.54a 1.08a 1.40a 3.75b 8.55a 8.90a 8.75a 40.25a
Weed-free for 10 DAT 0.48a 0.70a 1.39a 3.85b 4.08bc 6.23b 5.78bc 29.63c
Weed-free for 20 DAT 0.49a 0.65a 1.60a 4.13b 5.38abc 10.68a 7.90a 34.90b
Weed-free for 30 DAT 0.67a 0.85a 1.33a 6.10a 7.43ab 10.10a 7.45ab 37.75ab
Unweeded
0.41a 0.60a 0.55a 3.23b 3.45c 4.57c 4.55c 23.30d
═══════════════════════════════════════════════════════════
════
In a column, means a with common letter are not significantly different at 5% level by
DMRT
Crop Survival
Plants kept weed-free from transplanting up harvesting had significantly higher
percentage survival than the other of the treatments but comparable to 20 and 30 DAT
(Table 4). Plants kept unweeded had the lowest percentage survival however,
comparable to 10 DAT.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
13
Average Weight of Marketable, Non-marketable
and Marketable Yields
Table 5 shows the average weight of marketable and non-marketable and
marketable yields. The average marketable weight per plant was significantly higher in
plots kept weed-free but was comparable to those kept weed-free for 20 and 30 DAT.
However, the former was significantly higher than those kept weed-free for 10 DAT and
unweeded plants. In terms of the non-marketable yield per plot, there were significant
differences among the treatments. Plants kept weed-free and those weed-free for 20 and
30 DAT were comparable with each other but these treatments produce higher non-
marketable yield than those at 20 Table 4. Crop survival
═══════════════════════════════════════════════════════════
════
WEEDING
MEAN
DURATION (days)
(%)
───────────────────────────────────────────────────────────
────
Weed-free
68.00a
Weed-free for 10 DAT
37.75bc
Weed-free for 20 DAT
57.50ab
Weed-free for 30 DAT
67.75a
Unweeded
31.00c
═══════════════════════════════════════════════════════════
════
Means with a common letter are not significantly different at 5% by DMRT
Table 5. Average marketable weight, non-marketable, and marketable yields
═══════════════════════════════════════════════════════════
════
WEEDING
AVERAGE
YIELDS (kg/plot)
DURATION
WEIGHT
─────────
───────────────────
(days)
(g/plant)
Non-marketable
Marketable
───────────────────────────────────────────────────────────
────
Weed-free
121.45a
2.35a
3.80a
Weed-free for 10 DAT 53.94b
0.75b
1.35c
Weed-free for 20 DAT 100.65ab
2.15a
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
14
2.40b
Weed-free for 30 DAT 117.092a
2.25a
3.95a
Unweeded
54.69b
0.55b
0.70c
═══════════════════════════════════════════════════════════
════
In a column, means a with common letter are not significantly different at 5% level by
DMRT
DAT and unweeded plots. The marketable yields per plot were significantly higher in the
weed-free plants and those weed-free for 30 DAT than those weeded for 10 and 20 DAT
and the unweeded plants.
Total and Computed Yields, Yield
Reduction, and Benefit:Cost Ratio
The total and computed yields of plants kept weed-free up to harvesting was
markedly the highest compared to the rest of the treatments except for those plants kept
weed-free for 30 DAT as presented in Table 6. Yield reduction ranges from 5.69 to
82.11% for plants kept weed-free for 30 DAT and those unweeded. In terms of
benefit:cost ratio, the highest was realized from plants kept weed-free for 30 DAT
followed by those kept weed-free up to harvesting.
Pictorial Documentation
Figs. 1 and 2 show the overview of the experiment before harvest and the
harvested plants, respectively.
The weeding time (Table 1) required to remove G. parviflora, E. indica, D.
sanguinalis identified and counted weeds (Table 2) growing in association with the crop
increases with longer durations of weed control. This is attributed to more weeds with
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
15
well-
Table 6. Total and computed marketable yields, yield reduction and benefit:cost ratio
═══════════════════════════════════════════════════════════
════
WEEDING
TOTAL YIELD
COMPUTED
BENEFIT:
DURATION
YIELD REDUCTION YIELD COST
(days)
(kg/plot) (%)
(t/ha)
RATIO
───────────────────────────────────────────────────────────
────
Weed-free
6.15a
-
7.45a
31.73
Weed-free for 10 DAT 2.10c
65.85
2.70bc 16.63
Weed-free for 20 DAT 4.05b
34.14
4.30b
23.03
Weed-free for 30 DAT 5.80a
5.69
7.90a
34.86
Unweeded
1.10c
82.11
1.40c
-
═══════════════════════════════════════════════════════════
════
In a column, means a with common letter are not significantly different at 5% level by
DMRT established root system when allowed to grow for a longer duration making them
harder to uproot than at earlier period supporting the statement of Anderson (1983) that
weeding tool 20-30% of farmers’ time and the it accounted for only 2.0 to 6.0% of that
production cost.
Allowing crop-weed mixtures after 10 to 30 days from transplanting (DAT) did
not result to a significant increase in plant growth increments (Table 3) but significantly
affected four to seven weeks after transplanting. Results suggest that transplanted
Chinese kale crop can effectively compete with the weeds because they were given a
head-start.
Manifestation of crop-weed competition were noticeable as the association was
prolonged causing a remarkable reduction in crop survival, average plant weight,
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
18
marketable and total yields resulting to a tremendous yield reductions (Tables 4-6).
These repercussions indicated that the crop lost its competitiveness with the weeds for
growth factors essential for growth and development (Villareal and Wallace, 1969;
Anderson, 1983). Moody (1993) also stated that any weed growing in association with
the crop will reduce the vegetative dry matter potential of the crop. In this study,
allowing crop-weed mixtures from transplanting to harvesting resulted to 82.11% yield
reduction (Table 6) supporting several reports that crop-weed mixture reduced yields by
as much as 30% in carrot, 60% in onions and beets (Stanbold and Holms, 1956 cf. Crafts
and Robbins, 1962), and 52% in potato (King, 1985). Subramanian (1981) also reported
that weeds decrease soybean yields by reducing pod, branch, leaf, and flower numbers
per plant, seed number per pod, and plant dry weight. Bleasedale (1960) mentioned that
the presence of weed significantly reduced the weight of tops, total roots and
marketability of carrots. In lettuce, a maximum yield was obtained with a single weeding
25 days after transplanting (Cardona, 1977). Also, increasing the time that weeds
remained in plots before removal, the greater the reduction in garlic yield and quality
(Qasem, 1996). Yield reductions ranging from 6.12 to 88.57% was also reported by Diaz
(1998) in lettuce crop while 22.48-70.33% in cabbage crop (Atiwon, 1999).
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary
The study was conducted at the Balili Experimental Station, Benguet State
University, La Trinidad, Benguet from June to July 2007 to determine the effects of
weeding durations on the growth and yield, to establish the best time of weeding, and to
assess the economics of the various weeding durations in Chinese kale production.
Results showed that plants weed-free from transplanting up to harvesting and
weed-free for 30 days after transplanting (DAT) were comparable but considerably
required longer duration of weeding than the other treatments.
Small flower galinsoga (Galinsoga parviflora Cav.) was identified as the
predominantly weed species growing in association with the crop while the minor were
goosegrass (Eleusine indica L.) and crabgrass (Digitaria sanguinalis L.). The
population of G. parviflora at harvest was significantly higher in the unweeded plots than
the rest of the treatments. Plots weeded for 10, 20 and 30 DAT have comparable
population.
Plant growth increment measured in one, two and three weeks after transplanting
were not significant. But on the fourth measurement, growth increment was significantly
higher in plants weed-free for 30 DAT compared to the rest of the weeding durations. On
the fifth and sixth measurements, weed-free plants for 30 DAT had markedly higher
growth but comparable to weed-free and those weed-free for 20 DAT but were
considerably higher than those plants weed-free for 10 DAT and unweeded plots. On the
other hand, the weed-free plants had the highest increment but was comparable to weed-
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
20
free plants for 20 and 30 DAT on the seventh measurement. For the final height at
harvest, weed-free plants markedly had the tallest however, comparable with those plants
at 30 DAT. But the former was significantly taller compared to the rest of the treatments.
The average marketable weight per plant was significantly higher in plots kept
weed-free but was comparable to those kept weed-free for 20 and 30 DAT. However, the
former was significantly higher than those kept weed-free for 10 DAT and unweeded
plants. In terms of the non-marketable yield per plot, there were significant differences
among the treatments. Plants kept weed-free and those weed-free for 20 and 30 DAT
were comparable with each other but these treatments produce higher non-marketable
yield than those weed-free for 20 DAT and unweeded plots. The marketable yields per
plot were significantly higher in the weed-free plants and those weed-free for 30 DAT
than those weeded for 10 and 20 DAT and the unweeded plants. The total and computed
yields of plants kept weed-free up to harvesting was markedly the highest compared to
the rest of the treatments except for those plants kept weed-free for 30 DAT. Yield
reduction ranges from 5.69 to 82.11% for plants kept weed-free for 30 DAT and those
unweeded. In terms of benefit:cost ratio, the highest was realized from plants kept weed-
free for 30 DAT followed by those kept weed-free up to harvesting.
Conclusion
Based from the results of the study, plants kept weed-free and those weed-free for
30 days after transplanting had the highest yield and profitability. In conclusion, keeping
the plants weed-free for 30 days after transplanting could be done to reduce labor cost in
controlling in weeds for Chinese kale production.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
21
Recommendation
From the preceding results and discussions, it is recommended to keep the plants
weed-free for at least 30 days after transplanting. It is further recommended that a similar
study will be conducted on Chinese kale production during the dry cropping season.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
LITERATURE CITED
ANDERSON, W.P. 1983. Weed Science: Principles. St. Paul: West Publ. p. 655.
ANONYMOUS. 2006. Weed management in vegetable crops. IPM- University of
California.
_____. 2006. Chinese Broccoli. Wikipedia. The Free encyclop.
_____. 1975. The Philippine Recommends for Vegetable Crops. PCAR Series. No. 3:37.
_____. 1980. The effect of duration of weed competition on the growth and yield of Mungbean. Particip
ATIWON, A.B. 1999. Duration of crop-weed competition in transplanted cabbage. BS Thesis. BSU, L
BAWANG, F. T. 2006. Production and Postharvest Technologies of Vegetables in the
Mid-Elevation and High Altitude Tropics. Benguet State University, La Trinidad,
Benguet. Philippines. P. 56.
BLEASEDALE, J.K.A. 1960. Studies of Plant Competition in the Biology of Weeds. New York: McGr
BONGOLAN, F. and G.F. WELLS. 1981. Weed Control in upland crops in the
Philippine. In Proc. 6th Asian-Pacific Weed Sci. Soc. Conf. Bangalore, India.
Pp. 11-16
CARDONA, P.F. 1977. Weed competition in lettuce. Institute of Columbian
Agriculture, Bogota, Columbia 12(4):407-420.
CHAPMAN, S.R. 1976. Crop Production. San Francisco:W.H. Freeman Co. Pp. 165-193.
CRAFTS, A.S. and W. ROBBINS. 1976. Weed Control. New York: McGraw Hill Book Co. P. 96.
DIAZ, A.Y. 1998. Growth and yield of head lettuce as affected by the duration of weed competition. B
GUANTES, M.M. 1980. Weed control studies in sunflower. Phil. J. Weed Sci. 5:7-15.
KING, G.R. 1985. Farmer’s Weed Control Handbook. St. Louis, Missouri: Doanne Publ. P. 241.
KNOTT J.E. and J.R. DEANON, Jr. 1969. Vegetable Production in Southeast Asian. UPCA, Los Baño
MOODY, K. 1993. Weed Control in Rice using Non-chemical Method. NCPC-UPLB, College, Los Bañ
______ and E.C. PALLER, Jr. 1976. Manual in Weed Science Training Course. NCPC-UPLB, College
PALLER, E.C. and J. M. SORIANO. 1997. Weed Control in vegetable fields. In
Vegetable
Production (O.K. Bautista and R.C. Mabesa). Los
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
23
Baños: UPCA. Pp. 66-68.
QASEM, J.R. 1996. Weed competition in garlic. J. Hort. Sci. 71:41-48.
STALL, W. M. and J. A. DUSKY. n.d. Weed control in leafy vegetables. Univ. Of Florida, Gainesville
SUBRAMANIAN, S. 1981. All About Weed Control. New Delhi: Kalyani Pub. P. 315
THOMPSON, H.C. and W.C. KELLY. 1957. Vegetable Crops. New York: McGraw Hill Book Co. P.
VILLAREAL, R.A. and D. WALLACE. 1969. Vegetable Training Manual. Los Baños,
Laguna. P. 80.
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
APPENDICES
Appendix Table 1. Weeding time (hrs)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
1.13
0.97 0.73 0.78
3.61 0.91
T2
0.10
0.08 0.07 0.07
0.32 0.08
T3
0.53
0.33 0.32 0.18
1.36 0.34
T4
1.00
0.08 0.68 0.58
3.06 0.77
T5
0.00
0.00 0.00 0.00
0.00 0.00
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
0.154 0.051
Treatment
4
2.601 0.650
72.59**
3.26
5.41
Error
12
0.107 0.009
───────────────────────────────────────────────────────────
────
Total
19
2.063
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 22.67%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
25
Appendix Table 2. Growth increment one week after transplanting (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
0.66
0.50 0.70 0.30
2.16 0.54
T2
0.60
0.30 0.40 0.60
1.90 0.48
T3
0.80
0.40 0.46 0.30
1.96 0.49
T4
1.10
0.78 0.30 0.50
2.68 0.67
T5
0.34
0.60 0.20 0.50
1.64 0.41
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
0.252 0.084
Treatment
4
0.152 0.038
0.89ns
3.26
5.41
Error
12
0.512 0.043
───────────────────────────────────────────────────────────
────
Total
19
0.915
═══════════════════════════════════════════════════════════
════
ns = Not significant
Coefficient of variation = 39.94%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
26
Appendix Table 3. Growth increment two week after transplanting (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
1.1
1.4
1.3 0.5
4.30 1.08
T2
1.0
0.8
0.5 0.5
2.80 0.70
T3
0.8
0.7
0.6 0.5
2.60 0.65
T4
0.8
1.0
0.5 1.1
3.40 0.85
T5
0.8
0.6
0.5 0.5
2.40 0.60
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
0.322 0.107
Treatment
4
0.590 0.147
2.66ns
3.26
5.41
Error
12
0.666 0.055
───────────────────────────────────────────────────────────
────
Total
19
1.577
═══════════════════════════════════════════════════════════
════
ns = Not significant
Coefficient of variation = 30.40%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
27
Appendix Table 4. Growth increment three weeks after transplanting (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
1.50
1.40 0.80 1.90
5.60 1.40
T2
2.50
0.90 1.10 1.05
5.55 1.39
T3
1.90
1.70 1.00 1.80
6.40 1.60
T4
1.40
1.20 1.10 1.60
5.30 1.33
T5
0.70
0.40 0.60 0.50
2.20 0.55
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
1.313 0.438
Treatment
4
2.638 0.659
4.72*
3.26
5.41
Error
12
1.676 0.140
───────────────────────────────────────────────────────────
────
Total
19
5.627
═══════════════════════════════════════════════════════════
════
* = Significant
Coefficient of variation = 29.84%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
28
Appendix Table 5. Growth increment four weeks after transplanting (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
3.8
3.5
4.6 3.1
15.00
3.75
T2
3.0
4.5
4.6 3.3
15.40
3.85
T3
2.7
3.3
5.4 5.1
16.50
4.13
T4
3.7
7.3
5.7 7.7
24.40
6.10
T5
2.1
2.0
4.2 4.6
12.90
3.23
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
10.546 3.515
Treatment
4
19.563 4.891
4.35*
3.26
5.41
Error
12
13.489 1.124
───────────────────────────────────────────────────────────
────
Total
19
43.598
═══════════════════════════════════════════════════════════
════
* = Significant
Coefficient of variation = 25.18%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
29
Appendix Table 6. Growth increment five weeks after transplanting (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
6.4
10.1 13.7 4.0
34.20
8.55
T2
2.5
4.7 5.7 3.4
16.30
4.08
T3
4.4
4.0 5.5 7.6
21.50
5.38
T4
8.5
5.0 7.7 8.5
29.70
7.43
T5
2.7
2.0 5.4 3.7
13.80
3.45
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
22.933 7.644
Treatment
4
75.515 18.879 3.78*
3.26
5.41
Error
12
59.889 4.991
───────────────────────────────────────────────────────────
────
Total
19
158.337
═══════════════════════════════════════════════════════════
════
* = Significant
Coefficient of variation = 38.68%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
30
Appendix Table 7. Growth increment six weeks after transplanting (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
9.1
8.0 12.5 6.0
35.60
8.90
T2
4.6
9.8 4.6 5.9
24.90
6.23
T3
10.1
12.7 12.0 7.9
42.70
10.68
T4
10.0
10.6 10.8 9.0
40.40
10.10
T5
4.6
4.2 5.6 3.9
18.30
4.57
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
22.657 7.552
Treatment
4
108.847 27.212 9.27**
3.26
5.41
Error
12
35.225 2.935
───────────────────────────────────────────────────────────
────
Total
19
166.730
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 21.16%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
31
Appendix Table 8. Growth increment seven weeks after transplanting (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
8.4
8.6
8.7 9.3
35.00
8.75
T2
5.0
5.8
7.5 4.8
23.10
5.78
T3
8.6
9.9
6.1 7.0
31.60
7.90
T4
6.4
9.7
5.4 8.3
29.80
7.45
T5
4.0
4.7
4.8 4.7
18.20
4.55
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
5.237 1.746
Treatment
4
46.048 11.512 6.98**
3.26
5.41
Error
12
19.780 1.648
───────────────────────────────────────────────────────────
────
Total
19
71.065
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 18.65%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
32
Appendix Table 9. Final plant height (cm)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
33.4
45.6 42.2 39.8
161.00
40.25
T2
24.5
31.6 37.8 24.6
118.50
29.63
T3
33.6
36.4 34.6 35.0
139.60
34.90
T4
36.2
38.8 36.2 39.8
151.00
37.75
T5
17.2
28.6 25.6 21.8
93.20
23.30
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
160.649 53.550
Treatment
4
736.318 184.079 17.24** 3.26
5.41
Error
12
128.138 10.678
───────────────────────────────────────────────────────────
────
Total
19
1025.105
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 9.85%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
33
Appendix Table 10. Crop survival (%)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
56.0
51.0 80.0 85.0
272.0
68.00
T2
41.0
40.0 53.0 17.0
151.0
37.75
T3
41.0
68.0 80.0 41.0
230.0
57.50
T4
52.0
53.0 79.0 87.0
271.0
67.75
T5
36.0
31.0 45.0 12.0
124.0
31.00
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
1536.40 512.133
Treatment
4
4710.30 1177.575 5.21*
3.26
5.41
Error
12
2714.10 226.175
───────────────────────────────────────────────────────────
────
Total
19
8960.80
═══════════════════════════════════════════════════════════
════
* = Significant
Coefficient of variation = 28.70%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
34
Appendix Table 11. Average marketable yield (g/plant)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
95.24 152.63 106.67 131.25 485.788
121.447
T2
64.52
9.33 65.00 76.92 215.766
53.941
T3
96.77 94.12 63.33 148.39 402.611
100.653
T4
102.56 165.00 108.74 95.38 471.680
117.920
T5
66.67 78.26 29.41 44.44 218.778
54.694
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
2214.321 738.107
Treatment
4
17713.015 4428.254 4.95*
3.26
5.41
Error
12
10729.194 894.100
───────────────────────────────────────────────────────────
────
Total
19
30656.530
═══════════════════════════════════════════════════════════
════
* = Significant
Coefficient of variation = 33.32%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
35
Appendix Table 12. Non-marketable yield (kg/plot)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
0.8
2.2
3.0 3.4
9.40 2.35
T2
0.8
1.0
1.0 0.2
3.00 0.75
T3
1.0
3.8
1.8 2.0
8.60 2.15
T4
0.6
2.6
3.4 2.4
9.00 2.25
T5
0.8
0.8
0.4 0.2
2.20 0.55
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
4.870 1.623
Treatment
4
12.448 3.112
4.58*
3.26
5.41
Error
12
8.160 0.680
───────────────────────────────────────────────────────────
────
Total
19 25.478
═══════════════════════════════════════════════════════════
════
* = Significant
Coefficient of variation = 51.22%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
36
Appendix Table 13. Marketable yield (kg/plot)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
3.2
3.6
3.4 5.0
15.20
3.80
T2
1.2
1.8
1.6 0.8
5.40
1.35
T3
2.0
3.0
2.0 2.6
9.60
2.40
T4
3.4
4.0
3.8 4.6
15.80
3.95
T5
1.0
1.0
0.6 0.2
2.80
0.70
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
1.008 0.336
Treatment
4
33.388 8.347
28.68** 3.26
5.41
Error
12
3.492 0.291
───────────────────────────────────────────────────────────
────
Total
19
37.888
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 22.11%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
37
Appendix Table 14. Total yield (kg/plot)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
4.0
5.8
6.4 8.4
24.60
6.15
T2
2.0
2.8
2.6 1.0
8.40
2.10
T3
3.0
4.8
3.8 4.6
16.20
4.05
T4
4.0
6.6
6.4 6.2
23.20
5.80
T5
1.8
1.2
1.0 0.4
4.40
1.10
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
5.264 1.755
Treatment
4
79.028 19.757 16.94** 3.26
5.41
Error
12
13.996 1.166
───────────────────────────────────────────────────────────
────
Total
19
98.288
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 28.12%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
38
Appendix Table 15. Computed yield (t/ha)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
6.4
7.2
6.2 10.0
29.80
7.45
T2
2.4
3.6
3.2 1.6
10.80
2.70
T3
4.0
6.0
4.0 3.2
17.20
4.30
T4
6.8
8.0
7.6 9.2
31.60
7.90
T5
2.0
2.0
1.2 0.4
5.60
1.40
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
3.35 1.117
Treatment
4
131.36 32.840 22.81** 3.26
5.41
Error
12
17.28 1.440
───────────────────────────────────────────────────────────
────
Total
19
151.99
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 25.26%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
39
Appendix Table 16. Population of Galisoga parviflora (1 m x 1 m quadrant)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
0.0
0.0 0.0 0.0
0.0
0.00
T2
223.0 211.0 218.0 201.0
853.0
213.25
T3
231.0 216.0 221.0 190.0
858.0
214.50
T4
211.0 236.0 209.0 196.0
852.0
213.00
T5
286.0 255.0 269.0 273.0
1083.0
270.75
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
857.00 285.667
Treatment
4
175975.70 43993.925 318.12** 3.26
5.41
Error
12
1659.50 138.292
───────────────────────────────────────────────────────────
────
Total
19
178492.20
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 6.45%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
40
Appendix Table 17. Population of Eleucine indica (1 m x 1 m quadrant)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
0.0
0.0 0.0 0.0
0.0
0.00
T2
205.0 196.0 213.0 211.0
825.0
206.25
T3
180.0 207.0 159.0 223.0
769.0
192.25
T4
154.0 194.0 186.0 215.0
749.0
187.25
T5
239.0 208.0 197.0 189.0
833.0
208.25
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
766.80 255.600
Treatment
4
127370.20 31842.550 73.59** 3.26
5.41
Error
12
5192.20 432.683
───────────────────────────────────────────────────────────
────
Total
19
133329.20
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 13.10%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
41
Appendix Table 18. Population of Digitaria sanguinalis (1 m x 1 m quadrant)
═══════════════════════════════════════════════════════════
════
R E P L I C A T I O N
TREATMENT ─────────────────────── TOTAL MEAN
I II
III IV
───────────────────────────────────────────────────────────
─────
T1
0.0
0.0 0.0 0.0
0.0
0.00
T2
206.0
86.0 211.0 92.0
595.0
148.75
T3
91.0 115.0 127.0 97.0
430.0
107.50
T4
87.0 91.0 103.0 73.0
354.0
88.50
T5
255.0 211.0 98.0 117.0
681.0
170.25
═══════════════════════════════════════════════════════════
════
Analysis of Variance
═══════════════════════════════════════════════════════════
═══
Source of Degrees of Sum of Mean Computed TABULAR F
variation freedom squares square F 0.05 0.01
───────────────────────────────────────────────────────────
────
Replication 3
6918.40 2306.133
Treatment
4
69820.50 17455.125 8.19**
3.26
5.41
Error
12
25569.10 2130.758
───────────────────────────────────────────────────────────
────
Total
19
102308.00
═══════════════════════════════════════════════════════════
════
** = Highly significant
Coefficient of variation = 44.82%
Growth and Yield of Chinese Kale (Brassica oleracea var. alboglabra) as Affected by Duration
of Weed Control /Janet S. BAlicdang. 2007
Document Outline
- Growth and Yield of Chinese Kale(Brassica oleracea var. alboglabra) as Affected by Duration of Weed Control.
- BIBLIOGRAPHY
- ABSTRACT
- TABLE OF CONTENTS
- INTRODUCTION
- REVIEW OF LITERATURE
- Description of the Crop
- Yield Losses Due to Weeds
- Crop-Weed Competition
- Weed Control
- MATERIALS AND METHODS
- RESULTS AND DISCUSSION
- Weeding Time
- Identified Weed Species and Population
- Growth Increment and Final Height
- Crop Survival
- Average Weight of Marketable, Non-marketableand Marketable Yields
- Total and Computed Yields, YieldReduction, and Benefit:Cost Ratio
- Pictorial Documentation
- SUMMARY, CONCLUSION AND RECOMMENDATION
- LITERATURE CITED
- APPENDICES