BIBLIOGRAPHY
ARAÑAS, EMMANUEL T. OCTOBER 2008. Effect of Various Colors of
Polyethylene on the Growth and Yield of Strawberry. Benguet State University, La
Trinidad, Benguet.
Adviser: Franklin G. Bawang, MSc
ABSTRACT

The study was conducted to determine the effect of the different color of
polyethylene plastic mulch on the growth and yield of strawberry, to identify the best
color of polyethylene plastic mulch appropriate for strawberry production and to
determine if the different colors of polyethylene plastic mulch are suitable mulching
materials.

The days to first flower appearance and days from transplanting to first harvest
showed that plants mulched with white polyethylene plastic enhanced earlier flower
formation and harvesting. The days from transplanting to last harvest showed that
strawberry plants mulched with polyethylene plastics had highly significant effects as
compared to the plants that were not mulched with polyethylene plastics.

Strawberry plants mulched with black polyethylene plastic had significantly
higher marketable yield per plot over the plants that were mulched with the other colored
polyethylene plastics. In the total yield per plot and computed yield per hectare
strawberry plants mulched with black, yellow and orange polyethylene plastics had the
highest total yield of berries produced.

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The results on the percentage of abnormal fruit showed that black polyethylene
plastic mulch had the lowest percentage as compared with the other plastic mulch used.

Using different polyethylene plastic mulch on the growth and yield of strawberry
did not have significant effect on the percentage of fruit set, non – marketable yield,
monthly sugar content and incidence of insect pest.

Lastly, the cost and return analysis shows that black polyethylene plastic used as a
mulching material induced a higher return on investment followed by silver polyethylene
plastic.

ii

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TABLE OF CONTENTS

Page
Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
REVIEW OF LITERATURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
MATERIALSD AND METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
RESULTS AND DISCUSSION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Days to first flower appearance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Days from transplanting to first harvest. . . . . . . . . . . . . . . . . . . . . . . . .
12

Days from transplanting to last harvest. . . . . . . . . . . . . . . . . . . . . . . . .
14

Percentage of fruit set. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16

Percentage of abnormal fruit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17

Marketable yield per plot (kg) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17

Non – marketable yield per plot (kg) . . . . . . . . . . . . . . . . . . . . . . . . . . .
19
Total yield per plot (kg) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19



Computed yield per hectare (t/ha) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20

Taste test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20

Monthly sugar content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21

Incidence of strawberry mites and strawberry leaf spot . . . . . . . . . . . .
23

Strawberry leaf spot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23
iii

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Cost and return analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24

Other observation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
SUMMARY, CONCLUSION AND RECOMMENDATION

Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29
Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29
LITERATURE CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
APPENDICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32

iv

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INTRODUCTION

Nature of the study

Strawberry (fragaria x ananassa) is one of the most commonly visited fruit by
tourist here in Baguio and La Trinidad, Benguet province where much of it is grown or
produced. It belongs to the family Rosaceae; its fruit is technically known as an accessory
fruit where the fleshy part is derived not from the plant ovaries (achene’s) but from the
peg at the bottom of the bowl-shaped hypanthium’s that hold the ovaries.

There are two main types of strawberry plants: short day plants and ever bearing
plants. Short day plants produce a single crop each year when the photoperiod is under 14
hours per day that usually occurs during cool summer temperature. Ever bearing plants
produce fruit throughout the growing season and there are two types such as; long day
and day neutral plants. As the name suggests, long day plants have continuous flowering
through the summer as the days grow longer, on the other hand, day neutral plant flower
several times per year regardless of the length of the photoperiod. The majority of the
strawberry producers use short day plant; however, the use of day neutral plants is
increasing in California.

The variety Sweet Charlie is considered a short day cultivar, early fruiting and
produces fruit that has a distinctively sweet flavor and resistant to anthracnose (caused by
Colletotrichumacutatum). Plants of “Sweet Charlie” generally start producing ripe fruit
about two weeks earlier than the “Camarosa” variety. Sweet Charlie may vary in height
from 19 to 26 centimeters and width from 29 to 42 centimeters. The top of the leaves are
medium to dark green in color. The bottom of the leaves is colored yellow green. The
Effect of Various Colors of Polyethylene on the Growth
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Leaves demonstrate a distinct cupped appearance. This typical characteristic is often
confused with symptoms of powdery mildew. (Hort.Sci.Dep.,University of Florida)

The strawberry fruit is composed of many parts such as, the stem where the berry
is attached to the plant. The sepal is what remains of the flower of the plant after the
berry form. The bundle, the cortex and finally the epidermis surround the center of the
berry, or the pith. Located on the epidermis are the achenes or what are commonly
referred to as the seed of the strawberry. The fruit of the berry or the achene’s are what
we consider the seed of the berry, but in reality is the reproductive portion of the plant or
the fruit of the plant.

The technique of mulching is a practice that growers can undertake in strawberry
farm that will produce a result that one could never imagine. Mulching is the technique of
placing a protective skin of material on the top of the soil. Mulch comes in two basic
forms; organic and non-organic. The most commonly used in organic mulching on
strawberry is the coggon grass and straw while the most common item used in non-
organic mulching is the polyethylene plastic mulch.

Mulching is very necessary in strawberry because it serves as protection against
fruit rotting. The practice also minimizes weed growth and also prevents soil splattering
during heavy rains, thus keeps the fruit clean. Mulching is also necessary to the plant to
minimize the lose of soil moisture. To some extent, mulching reduces the temperature of
the soil, which is favorable to strawberry being a temperate plant.

La Trinidad, Benguet strawberry growers are using black polyethylene plastic
mulch because of its effectiveness and due to its advantages such as, increase early
Effect of Various Colors of Polyethylene on the Growth
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yields, aids in moisture retention, inhibits weed growth, reduces fertilizer leaching,
reduces soil compaction and cleaner product or it protects the fruit.

In the market, the prices of commercial mulching or the polyethylene plastic
mulch is high but even though farmers are still buying and using the product due to its
many advantages. What is not known also is the degree of effectiveness especially the
other colors, thus, the study is being conducted.
The objective of the study is to determine the effect of the different color of
polyethylene plastic mulch on the growth and yield of strawberry, to identify the best
color of polyethylene plastic mulch appropriate for strawberry production and to
determine if the different colors of polyethylene plastic mulch are suitable mulching
materials.

The study was conducted at the Balili experimental area, Benguet State
University, La Trinidad, Benguet from October 2007 to April 2008.










Effect of Various Colors of Polyethylene on the Growth
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REVIEW OF LITERATURE


Marr (1993), studied the effect of plastic mulch on vegetable. They successfully
grown muskmelon, tomatoes, peppers, cucumber, watermelons, and okra using plastics
mulch and have shown significant increase in earliness, yield and fruit quality.

Broadly (1992), found out that the growth, yield and more importantly the
harvesting quality of the fruit from these low growing plant are greatly affected by
weeds. As a result, strawberries are grown almost exclusively on mulch. Mulching is
needed especially during fruiting stage. Mulch is necessary to minimize direct contact of
fruit within the soil, thus the decay of berries is controlled.

In relation to weed control, Balaki (1992), reported that the area of strawberry
production does not increase due to high cost of weeding strawberry field. The cost of
weeding work account for almost 32% of the total cost of production. The same
researcher also pointed out that the farm labor supply during the peak season of
strawberry production become scarce.

Ricotta and Masiunas (1991), found that mulch plots covered with black
polyethylene conserve more moisture than the un mulched plot. Likewise, soil
temperature increased and sometimes hastened the growth of the crop, thus leading
earlier fruit development.

Assir et al. (1991), found out that the application of clear plastic mulch with or
without a fertilizer did not significantly increase the yield of lettuce grown in the fall
under green house in the Mediterranean mountains in Lebanon. Yield average from 31 to
Effect of Various Colors of Polyethylene on the Growth
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38 kg/50 heads. Leaf NO3 – N and total P level were higher in mulched than the un
mulched plants and always above the sufficiency level in all treatments.

The Hort. Sci. Dep., University of Florida (1988), found the benefits of
polyethylene mulch and organic mulch on vegetable and fruit production. Firstly, it
increased the yield. The largest benefits from black polyethylene mulch are the increase
in soil temperature in the bed, which promotes faster crop development and earlier yields.
Secondly, it aided in moisture retention. Mulch reduced evaporation from the bed soil
surface. As a result, a more uniform soil moisture regime is maintained and the frequency
of irrigation is reduced. Irrigation is still mandatory for mulched crops so that the soil
under the mulch doesn’t dry out excessively. Thirdly, it inhibits weed growth. Fourthly, it
reduced fertilizer leaching. Fertilizer placed in the bed under the mulch is less subject to
leaching by rainfall. As a result, the fertilizer program is more sufficient and the potential
exist for reducing traditional amount of fertilizer. Heavy rainfall that floods the bed can
still result in fertilizer leaching. This fertilizer can be replaced if the growers are using
drip irrigation, or it can be replaced with a liquid fertilizer injection wheel. Fifthly, it
decreased the soil compaction. Mulch acts a barrier to the action of rainfall, which can
cause soil crusting, compaction and erosion. Less compaction soil provides a better
environment for seeding emergence and root growth. Sixthly, it protected the fruits.
Mulch reduced rain splashed soil deposited on fruits. In addition, mulch reduced fruit rot
caused by soil inhibiting organism, because there is a protective barrier between the fruit
and the organism. Second to the last, it aided in fumigation. Mulches increased the
effectiveness of the soil fumigant chemical. It did not cause a barrier but allowed a water
layer to form under the mulch and it is this water layer that slowed down the loss of the
Effect of Various Colors of Polyethylene on the Growth
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fumigant. Lastly, it aided in managing other pest. Highly reflective mulches assisted in
the pest management strategies for pest and the deceases, especially viruses, they may
carry. Metabolized mulches have been shown to repel thrips and reduced the incidence of
tomato spotted wilt viruses in tomatoes.

In the study on Strawberry culture in Reunion Island, Catella (1987) found out
that using white plastic mulch coved increase the fruit medium weight and decreases
waste percentage. The same researcher observed that Sequoia variety improved fruit
production to a level of three hundred grams per plant followed by Aiko variety.

Nnadi et al. (1984), studied the effect of mulch and nitrogen on maize. They
concluded that maize yield responded significantly due to mulching. The mulch crop was
taller and more vigorous than the un mulched. They also claimed that mulch provided
better soil moisture, temperature regime and reduced weed competition.

Under South Carolina condition, Robbins and Schalk (1982), discovered that the
black aluminum and white polyethylene mulches increase the yield and early fruiting set
of spring grown tomatoes. Black transparent polyethylene mulches increased the soil
temperature resulting in sweet corn, yield earlier and higher than those from un mulched
soil. It reduced the incidence of aphids borne viruses and deterred such pest as aphids,
thrips, leaf miner on field, ornamentals and vegetable crops.

A reduction of 50% in water losses due to evaporation was realized using clear
polyethylene plastic mulch in soybean field.

Knott and Deanon (1967), earlier pointed out that mulch is used by farmers not
for the purpose of conserving moisture but to primarily control weeds. For green onions,
Effect of Various Colors of Polyethylene on the Growth
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the use of black polyethylene plastic mulch can be greatly advantageous in controlling
weeds.





















Effect of Various Colors of Polyethylene on the Growth
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MATERIALS AND METHODS

Materials

The materials used in the study were healthy runners of strawberry (Sweet
Charlie), different colors of polyethylene plastic mulch, tie wire, watering can, organic
and inorganic fertilizer, insecticide and fungicide, snap sack sprayer, weighing scale and
record book.

Methods

Experimental design and treatment. The experiment was laid out following the
randomized complete block design (RCBD) with 3 replications.

The treatments were represented as follows:

Treatments
T1 – no mulch (control)
T2 – black plastic
T3 – silver
T4 – white (clear)
T5 – light green
T6 – yellow
T7 – orange



Land preparation and fertilizer application. An area of 105 sq. meters was
thoroughly prepared and divided into 3 blocks with 7 plots in each block. Each plot was
measured 1m x 5m. Chicken manure was applied at the rate of 3/ha and inorganic
Effect of Various Colors of Polyethylene on the Growth
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fertilizer particularly triple fourteen (14 -14 -14) was applied at the rate of 500g per 5 sq.
meter – plot and properly incorporated with the soil.

Polyethylene plastic mulch application. The different colors of polyethylene
plastic mulch were placed on the top of each plot in a single layer. The plastic mulch was
secured tightly at the both ends of the plot to ensure unnecessary movement during strong
typhoons or rains. The plastic mulch was holed in a double row at a distance of 22 cm
between rows and hills.

Planting and irrigation. Healthy runners of Sweet Charlie were planted at the
holed portion of the polyethylene plastic that had been prepared. Irrigation was done just
after planting and every other day for two times until the plants were fully established.

Care and management. Other cultural management practices such as insect pest
and disease management, weeding and leaf pruning were done uniformly to ensure
optimum growth and development of the plants.

Harvesting. The strawberry fruits were harvested by hand picking throughout the
fruiting stage.



Data Gathered

1. Days to first flower appearance. This was the number of days from
transplanting to the day the first flower bud will occur.
2. Days from transplanting to first harvest. The number of days from
transplanting to first harvest were determined.
3. Days from transplanting to last harvest. The number of days from
transplanting to last harvest were determined.
4. Percentage of fruit set (%). Ten sample flowers was tagged with thread and
Effect of Various Colors of Polyethylene on the Growth
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the number of berries to be formed were counted and it was divided by 10 and multiplied
by 100.
5. Percentage of abnormal fruit (%). This was obtained by counting the
number of abnormal fruit and divided by the total numbers of fruits multiplied by 100.
6. Marketable yield per plot (kg). The large, medium and small sized berries that
were free from disease or bruises was considered as marketable yield.

7. Non – marketable per plot (kg). Rotten and decayed berries as well as the very
small fruit were considered as non – marketable yield.

8. Total yield (kg). The summation of total marketable and non – marketable
berries from the first to the last harvest was recorded.

9. Computed yield per hectare (t/ha). The marketable yield per plot was converted
to a hectare basis by multiplying it by 2,000. Two thousand is the number of plots per
hectare based on the plot dimension (1mx5m) used in the study.
10. Taste test. Flavor was judge by a panel of 30 members. They were rated the
fruit as:

Rate



Description
1
very sweet
2
sweet
3
slightly sweet
4
moderately sweet
5
moderately sour
6
slightly sour
7
sour
Effect of Various Colors of Polyethylene on the Growth
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11. Sugar content (°B). The sugar content of the fruit at the red ripe stage was
determined using a hand refractometer.

12. Incidence of Insect pest and disease. Observation was done on the presence of
insect pest and disease identified and rated them using the following scale:

a. Insect

Rating



Description
1
0 – 15% of the plants/plot are infested
2
15 – 30% of the plants/plot are infested
3
30 – 45% of the plants/plot are infested
4
45 60% of the plants/plot are infested
b. Disease
Rating



Description
1
0 – 15% of the plants/plot are infected
2
15 – 30% of the plants/plot are infected
3
30 – 45% of the plants/plot are infected
4
45 – 60% of the plants/plot are infected
13. Return of investment (ROI). All expenses incurred in the study was
recorded. The return of investment (ROI) was computed using the formula.


ROI% = Gross sales – total expenses x 100




Total expenses


14. Other observations.



Effect of Various Colors of Polyethylene on the Growth
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RESULTS AND DISCUSSIONS


Days to First Flower Appearance
There were significant differences that were observed among the different plastic
mulch on the days to first appearance of flower (Table 1). Results showed that the white
polyethylene plastic mulch effected the earliest days to the first flower appearance from
transplanting with a mean of 27.67 followed by the yellow polyethylene plastics. The
light green and orange polyethylene is comparable with each other attaining significantly
the same days to show flower appearance followed by the silver plastic mulch. The
strawberry plants that were not mulched with polyethylene took a significantly longer
period for the flower to appear from transplanting as compared to the strawberry plants
mulched with polyethylene plastics.

The study shows that using white polyethylene mulch took earlier days for the
flower to appear as compared to the other plastic mulch. Meanwhile, the study of Kudan
(2006) showed that planting strawberry during the off – season under green house took
21 days for the flower to appear. The polyethylene was used as greenhouse while in these
study, the polyethylene plastics were directly applied as mulch to the soil. This might be
one reason of their difference and it can also be attributed to the different environmental
conditions and planting season.

Days from Transplanting to First Harvest
Table 2 shows significant differences among the different treatments used in the
study affecting the days from transplanting to first harvest. The strawberry plants
mulched with white polyethylene plastic attained the earliest days to first harvest from
Effect of Various Colors of Polyethylene on the Growth
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Table 1. Days to first flower appearance


TREATMENT
MEAN


No – mulch
34.67a

Black
31.00bc

Silver
32.33ab

White
27.67d

Light green
29.67bcd

Yellow
29.00cd

Orange
29.67bcd

Means with the same letters are not significantly different at 5% level by DMRT

transplanting which is significantly comparable to strawberry plants mulched with yellow
and orange polyethylene plastics followed by strawberry plants mulched with black, light
green and silver plastics. The strawberry plants that were not mulched with polyethylene
attained the longest days to first harvest which took more days over the plants mulched
with polyethylene plastics.

The study reveals that using polyethylene plastic mulch in strawberry will
enhance earlier days to harvest from transplanting as compared to the strawberry plants
that was not been mulched with polyethylene plastics.

Days from Transplanting to Last Harvest
As shown in Table 3, there were slight significant differences on the days from
transplanting up to the last harvest. The strawberry plants that were not mulched with the
different plastic mulches attained the earliest days up to the last harvesting time when
Effect of Various Colors of Polyethylene on the Growth
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there are no more fruits to be harvested while all the strawberry plants mulched with
polyethylene plastics were all harvested on a much latter day.

The study may imply that strawberry plants mulched with polyethylene mulch
will induce longer days up to the last harvest. However , in the study of Himelrick and
Akridge (1999) stated that after 3 years of research on the feasibility of using variety of
plastic mulches to maximize production and possible extend fruiting season revealed that
using black plastic mulch is still the best choice for commercial planting of strawberry.

Percentage of Fruit Set

As presented in Table 4, there were no significant differences observed on the
percentage of fruit set as affected by the different polyethylene mulches used. However
numerical results showed that strawberry plants having black and white polyethylene
plastic mulches effected the highest percentage of fruit setting followed by strawberry
plants mulched with silver, light green, yellow and orange polyethylene plastics all of
which and are very much comparable to each other while the strawberry plants that was
not mulched attained a much lower percentage of fruit set.

Based on the results of the study, black and white polyethylene plastic mulch may
enhance high percentages of fruit set as was noted on strawberry plants that were
mulched with such materials which coved be very much helpful in the production of
strawberry fruit. High percentage of fruit set may possibly mean that there will be a high
expected yield to be produced granting that all the flowers will develop successfully into
a fruit.


Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

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Table 2. Days from transplanting to first harvest


TREATMENT
MEAN


No – mulch
58.67a

Black
53.33b

Silver
51.67bc

White
48.67c

Light green
50.67bc

Yellow
50.00c

Orange
49.67c

Means with the same letters are not significantly different at 5% level by DMRT

Table 3. Days from transplanting to last harvest


TREATMENT
MEAN


No – mulch
196.00b

Black
213.00a

Silver
213.00a

White
213.00a

Light green
213.00a

Yellow
213.00a

Orange
213.00a


Means with the same letters are not significantly different at 5% level by DMRT



Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

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Table 4. Percentage of fruit set (%)


TREATMENT
MEAN


No – mulch
93.33b

Black
100.00a

Silver
96.67ab

White
100.00a

Light green
96.67ab

Yellow
96.67ab

Orange
96.67ab

Means with the same letters are not significantly different at 5% level by DMRT



Table 5. Percentage of abnormal fruit (%)



TREATMENT
MEAN


No – mulch
19.99ab

Black
13.22c

Silver
14.64bc

White
17.97abc

Light green
15.91bc

Yellow
15.65bc

Orange
21.74a

Means with the same letters are not significantly different at 5% level by DMRT



Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

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Percentage of Abnormal Fruit
The results in Table 5 shows significant differences observed among the different
polyethylene plastic mulches used affecting percentage of abnormal fruits. The
strawberry plants applied with orange polyethylene plastic mulch affected the highest
percentage of abnormal fruits. It was followed by the strawberry plants that were not
mulched and plants mulched with white polyethylene plastics while the strawberry plants
mulched with silver, light green and yellow polyethylene plastic obtained comparable
percentages. The strawberry plants mulched with black polyethylene plastic attained the
lowest percentages of abnormal berries.

Based on the data presented, the black polyethylene plastic decreases the
production of abnormal berries of strawberry plant which is very good for the market and
commercial trade of the commodity because if the production of abnormal fruit or non –
marketable berries will be significantly lowered, the total yield will surely increase which
will be translated to higher profits.

Marketable Yield per Plot (kg)
With regards to the marketable yield per plot, there were significant differences
that were observed in Table 6 showing the effects of the different polyethylene plastic
mulches on the yield performance of strawberry plants. Statistically, the black, yellow
and orange polyethylene plastic mulches affected the highest marketable yield per plot
which is also comparable with strawberry plants mulched with silver and white
polyethylene plastics. Meanwhile, strawberry plants that were un mulched obtained the
least produced marketable berries per plot which is almost half the yield of strawberry
plants mulched with the various colored polyethylene plastics.
Effect of Various Colors of Polyethylene on the Growth
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Table 6. Yield per plot





Treatment
Marketable
Non –
Total yield
Computed

yield per
marketable per plot (kg)
yield per
plot (kg)
yield per
hectare
plot (kg)
(t/ha)





No mulch
7.77c
2.79a
10.56c
21.11c

Black
14.68a
1.92b
16.60a
33.19a

Silver
12.95ab
2.13ab
15.08ab
30.16ab

White
11.24b
2.12ab
13.36b
26.73b

Light green
12.53ab
2.29ab
14.83ab
29.65ab

Yellow
14.00a
2.73a
16.73a
33.46a

Orange
13.99a
2.58ab
16.57a
33.15a

Means with the same letters are not significantly different at 5% level by DMRT

Based on the results of the study, using polyethylene plastic as mulching materials
can increase the marketable yield of strawberry plants. The results agrees with the results
of the study of Himelrick and Akridge (1999) as was previously discussed in Table 3
stating that the use of plastic mulches increases production and possibly extending the
fruiting periods.

Non – Marketable Yield per Plot (kg)
Table 6 shows the influence of the various color of polyethylene plastic mulches
on the production of non – marketable berries per plot.

Numerically, results reveals that strawberry plants that were not mulched and
applied with yellow polyethylene plastics produced the highest non – marketable yield of
Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

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berries followed by strawberry plants mulched with silver, white, light green and orange
polyethylene plastics which is comparable with each other. The lowest non – marketable
berries which significantly differed from all the other treatments was produced from
strawberry plants mulched with black polyethylene plastics.

The results of the study means that using black polyethylene plastic coved
possibly decrease the production of non – marketable berries which is significantly
resistant to the economic aspect of production. On the contrary, the application of other
polyethylene plastic mulching materials including its non application may increase the
more production of berries which are considered as unfit for the market or with
abnormalities.

Total Yield per Plot (kg)
The total yield per plot as influenced by the various polyethylene plastic mulches
is shown in Table 6.Statistical analysis shows highly significant differences between all
the treatments. Strawberry plants mulched with yellow, black and orange polyethylene
plastics produced the highest total marketable yield of berries followed by the plants
mulched with light green and silver polyethylene plastics but it is also comparable to the
plants mulched with white polyethylene plastics. The strawberry plants that were not
mulched obtained the lowest total yield which significantly differed to the strawberry
plants mulched with polyethylene plastics.

The results corroborates with the study of Pangus (2000) that the effect of the
different mulching materials on the growth and yield of strawberry showed that black
polyethylene plastic mulch enhanced the production of higher total marketable yield
which is highly significant as compared to the other mulching materials used. Likewise,
Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

20
the strawberry plants that were not mulched attained the lowest total yield as compared to
the strawberry plants mulched with the different polyethylene plastics obtaining higher
total yield which might be attributed to the protective effect of the plastics thus lessening
the non – marketable qualities of the berries produced.

Computed Yield per Hectare (t/ha)

Statistical results in Table 6 shows that the computed yield per hectare followed
the same trend as the total yield per plot where in strawberry plants applied with black,
yellow and orange polyethylene plastic mulches out yielded the rest of the entries
evaluated.

However, numerical figures shows that strawberry plants mulched with yellow
polyethylene plastics produced higher yield per hectare followed by plants mulched with
orange and black polyethylene plastics. The lowest computed yield per hectare was
obtained from plants that were not mulched.

Taste Test

As presented in Table 7, the application of polyethylene plastic mulch affected the
taste of strawberry fruits as reflected in the taste test evaluations. The results of the taste
test revealed that in terms of sweetness, fruits produced from strawberry plants mulched
with polyethylene plastics were rated by the evaluators to be sweeter as compared to the
fruits of strawberry plants that had not been mulched.

In the entire taste test evaluation, results showed that all the strawberry fruits were
evaluated as having a moderately sweet taste except for the berries produced in the plants

Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

21
Table 7. Taste test





TREATMENT
SOUR
SLIGHTLY
MODERATELY
SWEET

SWEET
SWEET






No – mulch
10
8
10
2

Black
3
3
15
9

Silver
7
3
14
6

White
9
4
12
5

Light green
9
3
11
7

Yellow
5
10
9
6

Orange
3
1
15
11



mulched with yellow polyethylene which is rated to be less moderately sweet and the
berries produced from plants without mulching materials.

Monthly Sugar Content
The monthly sugar content from January, February and March is presented in
Table 8. The sugar content of strawberry fruits during the month of January were not
significantly affected by the various color of polyethylene plastic mulches as well as the
plants that were not mulched. However, numerical figures showed that strawberry plants
mulched with white plastics and plants that were not mulched had the highest sugar
content while plants mulched with orange plastic had the lowest sugar content.
In the month of February, statistical results showed no significant differences
among the treatments. Numerically, strawberry plants mulched with yellow polyethylene
Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

22
Table 8. Monthly sugar content (°B)




TREATMENT
JANUARY
FEBRUARY
MARCH




No – mulch
6.53a
9.40a
7.13b

Black
6.20a
8.40a
9.80a

Silver
6.27a
8.33a
9.80a

White
6.53a
8.33a
9.13a

Light green
6.40a
9.40a
9.57a

Yellow
6.07a
10.33a
9.73a

Orange
5.73a
9.53a
9.93a

Means with the same letter are not significantly different at 5% level by DMRT

plastics had the highest sugar content while plants mulched with silver and white plastics
were the lowest, although it s comparable with the sugar content of fruits obtained from
plants mulched with black, light green, orange plastics and strawberry plants that were
not mulched.

For the month of March, all strawberry plants mulched with polyethylene plastics
attained the highest sugar content and it is comparable with each other except the
strawberry plants that were not mulched obtaining the lowest sugar content which is
significantly different from plants mulched with the different polyethylene plastic
mulches.

The higher sugar content of fruits was obtained from fruits of the plants mulched
with various polyethylene plastics which could be attributed to the higher temperature
brought about by the plastic mulches. Tipayno (1976) has pointed out that temperature of
Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

23
the season affects the sweetness of strawberry fruits.

a. Incidence of Strawberry Mites (Phytonemos pallidus)

As shown in Table 9, strawberry plants mulched with polyethylene white plastic
showed the highest incidence of strawberry mite infestations but are comparable with the
plants mulched with light green, silver, yellow, orange and the strawberry plants that had
no mulch. The strawberry plant mulched with black plastic obtained the lowest incidence
of mites but it is not significantly different with all of the treatments.

The results may imply that the application of black plastic mulch will lessen the
infestation of mites on strawberry plants.

The presence of mites is often seriously felt during hot, dry growing months when
numerous mites retard the growth of strawberry plant which may results in plant death.

Table 9. Incidence of Insect Pest and Disease


TREATMENT
MEAN


No – mulch
2.00ab

Black
1.33b

Silver
1.67ab

White
2.33a

Light green
2.00ab

Yellow
1.67ab

Orange
1.67ab

Means with the same letter are not significantly different at 5% level by DMRT

Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

24

b. Strawberry Leaf Spot


The occurrence of strawberry leaf spot disease did not seriously effect the growth
and yield of the strawberry plants.

The disease is caused by the fungus Mycosphaerella fragariae. Leaf spot infects
the leaves, petioles runners, fruits stalk (pedicles) and berry caps or calyxes. Small dark
purple to reddish – purple round spot appeared on the upper leaf surfaces and only the
young succulent parts are infected by the leaf spot fungus (Ries 1996).

Cost and Return Analysis
Table 10 presents the cost and return analysis of producing strawberry using
various polyethylene mulch as well as the sales of marketable and non – marketable
berries and their ranks according to profitability.

The use of black polyethylene mulch attained the highest return on investment of
44.99 %or Php .44 for every peso spent in strawberry production. This was followed by
silver polyethylene plastics attaining 22.67%, orange polyethylene plastics with 19.38%,
yellow (13.94%), light green (2.15%), white (12.33%) and lastly the strawberry plant that
were not mulched which obtained 24.07%. White polyethylene plastics attained negative
ROI which might be due to the high prices of the polyethylene plastics. The strawberry
plants that were not mulched obtained the least negatively ROI as it had the lowest
marketable yield.

In addition to productivity, it was previously cited that Himelrick and Akridge
(1999) stated that inconsistent performance of other mulches and their cost, availability
and weed control factors, all suggest that black plastic mulch is the most effective and
efficient choice.
Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

25
Table 10. Cost and return analysis




VARIOUS POLYETHYLENE MULCH

ITEM
No
Black
Silver
White
Light
Yellow Orange

mulch
green








Yield (kg)
31.67
49.79
45.24
40.09
44.48
50.19
49.72









Sales (Php)
1426.75 2616.00 2213.25 1938.25 2158.25 2542.75
2437.50









Farm inputs (Php)
Polyethylene
-
28.50
28.50
312.50 217.00
336.00
146.00
Seedlings
720.00
720.00 720.00 720.00 720.00
720.00
720.00
Chicken
42.00
42.00
42.00
42.00
42.00
42.00
42.00
manure
Urea
7.14
7.14
7.14
7.14
7.14
7.14
7.14
14 - 14 -14
34.50
34.50
34.50
34.50
34.50
34.50
34.50
Lannate
82.86
82.86
82.86
82.86
82.86
82.86
82.86
Romectin
108.57
108.57 108.57 108.57 108.57
108.57
108.57
Paspas
64.29
64.29
64.29
64.29
64.29
64.29
64.29
Byleton
64.29
64.29
64.29
64.29
64.29
64.29
64.29
Thiram
54.29
54.29
54.29
54.29
54.29
54.29
54.29
Gasoline
31.14
31.14
31.14
31.14
31.14
31.14
31.14
Labor







Land
57.14
57.14
57.14
57.14
57.14
57.14
57.14
preparation
Polyethylene
-
16.67
16.67
16.67
16.67
16.67
16.67
installation







Planting
14.29
14.29
14.29
14.29
14.29
14.29
14.29
Weeding
320.00
200.00 200.00 320.00 320.00
320.00
320.00
Irrigation
107.14
107.14 107.14 107.14 107.14
107.14
107.14
Leaf pruning
171.43
171.43
171.43 171.43 171.43
171.43
171.43
Total Expenses
1879.08 1804.25 1804.25 2208.25 2112.75 2231.75
2041.75








Net Income/loss
-452.32 811.75 409.00
-270.00
45.50
311.00
395.75
(Php)
ROI (%)
-24.07
44.99
22.67
-12.23
2.15
13.94
19.38








Rank
7
1
2
6
5
4
3









Note: Selling price during harvest = Php 45.00 – 100.00/kg




Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

26
Other observation

During rainy season or heavy rains, the strawberry plants that were not mulched
with polyethylene plastic was damaged specially the flowers and fruits. The rain
splattering the soil caused soil erosion and after the rain, a few roots of the strawberry
were exposed.

Early and heavy rains during the fruiting season caused fruit cracking and rotting
of fruits. Some insect pest also damaged the berries like slugs and worms which bored the
berries that made it non – marketable.

On weed growth, it was observed that the plot beds mulched with white, light
green, yellow and orange polyethylene plastics had the fastest growth of weeds that tends
to move up the plastic mulch which caused water stagnant at the surface area of the
polyethylene that caused fruit rotting. The sunlight can directly pass through the
polyethylene plastic mulch enhancing faster growth of the weeds which is comparable to
the strawberry plants that were not mulched with plastics.















Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

27

SUMMARY, CONCLUSION AND RECOMMENDATION

Summary

The was study was conducted to determine the effect of the different color of
polyethylene plastic mulch on the growth and yield of strawberry , to identify the best
color of polyethylene plastic mulch appropriate for strawberry production and to
determine if the different color of polyethylene plastic mulch are suitable mulching
materials. The study was conducted at the Balili experimental area, Benguet State
University, La Trinidad, Benguet from October 2007 to April 2008.

Based on the study, the following results were obtained. Highly significant
differences was observed on the days to first flower appearance; strawberry plants
mulched with white polyethylene plastic mulch were the earliest to show flower
appearance while the strawberry plants with no mulch had the longest day to produce
flower as compared to the plants mulched with polyethylene plastics. The same results
were obtained from the days from transplanting to last harvest. The marketable yield per
plot showed highly significant results with strawberry plants mulched with the various
polyethylene plastics attained as having attained the highest marketable berries while the
strawberry plants that were not mulched with polyethylene plastics had the lowest
marketable fruit produced. Statistical analysis showed that strawberry plants mulched
with black, yellow and orange polyethylene plastic attained the highest total yield per plot
which is comparable to each other while strawberry plants that were not mulched with
plastics had the lowest yield. The results on the percentage of abnormal fruit showed that
the strawberry plants mulched with orange plastics had the highest percentage of
Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

28
abnormal berries while plants mulched with black plastics attained the lowest percentage
of abnormality.

There were no significant differences observed on the percentage of fruit set, non
– marketable yield, monthly sugar content, and incidence of insect pest.

As compared with the other treatments, strawberry plants mulched with black
polyethylene plastic attained the highest return on investment based on the results of the
study while the strawberry plants with no mulch and plants mulched with white plastics
obtained negative return on investments.

Conclusion

Based from the results, the use of black polyethylene plastics as a mulching
material for strawberry production enhanced higher percentage of fruit set; lowered
percentage of abnormal fruit produced and affected lesser non – marketable berries as
well as influencing higher return on investment. Likewise, using white polyethylene
plastic as mulch enhanced earlier days to flower appearance and days from transplanting
to the last harvest. On the other hand, the use of yellow polyethylene plastic is
comparable with black polyethylene if marketable yield is to be considered.

Recommendation

From the proceeding results and discussions, using black polyethylene plastic as a
mulching material for the growing of strawberry is highly recommended since it was
found out to be effective and it enhanced higher profits.

Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

29

LITERATURE CITED

ASSIR, A.L.,IG. RHEIZ and R.V. KROURY. 1991. Response of fall green house cost
Lettuce to clear mulch and nitrogen fertilizer. J. Plant Nutrition 50: 1017 – 1022.

BALAKI, E.T. 1992. Crop protection and Cultural Management, studies on
strawberry.Benguet State University Technical Bulletin, Benguet State University,
La Trinidad, Benguet. P. 20.

BROADLEY, R.H. 1992. Protect your strawberry. Queensland Department of Primary
Industries information series. Pp. 34 – 35.

CATELLA G. 1987. Strawberry Culture in Reunion Island. International Training Course.
Southern Hemisphere close to the topic of Capricorn, Colony of France.P.4.

HIMILRICK, D. and AKRIDGE, R. 1999. aq. auburn. edu/aaes/communication/…/
spring 99/strawberry.html

HORT. SCI. DEP. 1988. Florida Cooperative Extension service, Institute of food and
Agricultural Science, University of Florida.

KNOT, J.E. and J.R. DEANON. 1967. Vegetable production in South Asia. College of
Agriculture, University of the Philippines, College of Los Banos, Laguna. P.
310.MARR. C.W. 1993. Plastic mulches for vegetable, Kansas State University
Agricultural Experiment Station and Cooperative Extension Service, Kansas State
University.

KUDAN, S.L. 2006. Performance of Strawberry “Sweet Charlie” 1993 and 2007
Introduction using mother plants and runners chilled at various duration planted
during off season under green house in La Trinidad, Benguet.PhD. dissertation.
Benguet State University, La Trinidad, Benguet. Pp. 1 – 106.

MARR. C.W. 1993. Plastic Mulches for Vegetable, Kansas State University Agricultural
Experiment Station and Cooperative Extension Service, Kansas State University.

NNADI, L.; B.T. KANG and E.N.O.IWUAFOR. 1984. Effect of mulch and nitrogen on
maize Southern Guinea Savanna, Central Nigeria. IITA Annual Report
International Institute of Tropical Agriculture, Oyo Road, Ibadan, Nigeria. Pp.164
– 165.

PANGOS, N.K. 2000. Effect of Different Mulching Material on the Growth and Yield of
Strawberry. P.15.

Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

30
RICOTTA, J..A. and J.B. MASIUNAS. 1991. The effect of black plastic mulch and weed
control strategies on herb yield. Department of Horticulture, University of
Illionois. Horticulture Science 26 (5).Pp. 539 – 540.
RIES, S.M. 1996. Integrated Pest Management, Strawberry leaf spot.
www.ipm.uiuc.edu/fruits/disease/strawberry_leaf_disease/index.html

ROBBINS, L.M. AND J.M. SCHALK. 1982. Reflective Mulches Influence Plant
Survival, Production and Insect control in fall Tomatoes. Louisiana State
University Agricultural center, Chase, Los Angeles. P. 848.

TIPAYNO, A.C. 1976. Growth and Yield of Strawberry as affected by Planting Season
and Variety under MSAC condition, Unpublished Masteral Thesis. MSAC, La
Trinidad,Benguet. P.38

















Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

31


APPENDICES



TREATMENT REPLICATIONS
I II III TOTAL MEAN






T1
34.00
36.00
34.00
104.00
34.67

T2
32.00
34.00
27.00
93.00
31.00
T3
31.00
32.00
34.00
97.00
32.33
T4
27.00
29.00
27.00
83.00
27.67
T5
29.00
31.00
29.00
89.00
29.67
T6
29.00
31.00
27.00
87.00
29.00
T7
29.00
31.00
29.00
89.00
29.67
Appendix Table 1. Days to first flower appearance

Analysis of Variance








Source of
Degrees of
Sum of
Mean of
Computed TABULAR F
variation
freedom
squares
square
F
0.05
0.01







Replication
2
22.571
11.286

Treatment
6
97.810
16.302
7.31**
0.0255 0.0018
Error
12
26.762
2.230








TOTAL
20
147.143


** - highly significant



Coefficient of Variation = 4.88%
Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

32
Appendix Table 2. Days from transplanting to first harvest


TREATMENT REPLICATIONS
I II III TOTAL MEAN






T1
58.00
60.00
58.00
176.00
58.67

T2
54.00
58.00
48.00
160.00
53.33
T3
51.00
54.00
50.00
155.00
51.67
T4
48.00
50.00
48.00
146.00
48.67
T5
50.00
51.00
51.00
152.00
50.67
T6
51.00
51.00
48.00
150.00
50.00
T7
50.00
51.00
48.00
149.00
49.67


Analysis of Variance








Source of
Degrees of
Sum of
Mean of
Computed TABULAR F
variation
freedom
squares
square
F
0.05
0.01










Replication
2
41.238
20.619

Treatment
6
205.238
34.206
11.81**
0.0092 0.0002
Error
12
34.762
2.897








TOTAL
20
281.238


** - highly significant



Coefficient of Variation = 3.29%
Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

33
Appendix Table 3. Days form transplanting to last harvest


TREATMENT REPLICATIONS
I II III TOTAL MEAN






T1
197.00
197.00
194.00
588.00
196.00

T2
213.00
213.00
213.00
639.00
213.00
T3
213.00
213.00
213.00
639.00
213.00
T4
213.00
213.00
213.00
639.00
213.00
T5
213.00
213.00
213.00
639.00
213.00
T6
213.00
213.00
213.00
639.00
213.00
T7
213.00
213.00
213.00
639.00
213.00


Analysis of Variance








Source of
Degrees of
Sum of
Mean of
Computed TABULAR F
variation
freedom
squares
square
F
0.05
0.01










Replication
2
0.857
0.429

Treatment
6
743.143
123.857
289.00**
0.3966 0.0001
Error
12
5.143
0.429








TOTAL
20
749.143


** - highly significant



Coefficient of Variation = 0.31%

Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

34
Appendix Table 4. Percentage of fruit set (%)


TREATMENT REPLICATIONS
I II III TOTAL MEAN






T1
90.00
100.00
90.00
280.00
93.33

T2
100.00
100.00
100.00
300.00
100.00
T3
100.00
90.00
100.00
290.00
96.67
T4
100.00
100.00
100.00
300.00
100.00
T5
90.00
100.00
100.00
290.00
96.67
T6
90.00
100.00
100.00
290.00
96.67
T7
100.00
90.00
100.00
290.00
96.67


Analysis of Variance








Source of
Degrees of
Sum of
Mean of
Computed TABULAR F
variation
freedom
squares
square
F
0.05
0.01










Replication
2
28.571
14.286

Treatment
6
95.238
15.873
0.63ns
0.5841 0.7079
Error
12
304.762
25.397








TOTAL
20
428.571


ns - not significant



Coefficient of Variation = 5.19%





Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

35
Appendix Table 5. Percentage of abnormal fruit (%)


TREATMENT REPLICATIONS
I II III TOTAL MEAN






T1
22.12
19.01
18.85
59.98
19.99

T2
14.27
12.46
12.94
39.67
13.22
T3
13.88
13.40
16.64
43.92
14.64
T4
18.25
19.00
16.65
53.90
17.97
T5
16.52
17.10
14.10
47.72
15.91
T6
14.52
17.18
15.26
46.96
15.65
T7
29.33
21.53
14.37
65.23
21.74


Analysis of Variance








Source of
Degrees of
Sum of
Mean of
Computed TABULAR F
variation
freedom
squares
square
F
0.05
0.01










Replication
2
28.886
14.433

Treatment
6
165.699
27.617
3.03*
0.2456 0.0485
Error
12
109.489
9.124








TOTAL
20
304.055


* - significant



Coefficient of Variation = 17.75%





Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

36
Appendix Table 6. Marketable yield per plot (kg)


TREATMENT REPLICATIONS
I II III TOTAL MEAN






T1
7.71
7.92
7.67
23.30
7.77

T2
15.38
13.29
15.36
44.03
14.68
T3
13.09
14.18
11.59
38.86
12.95
T4
11.72
11.10
10.90
33.72
11.24
T5
11.66
13.18
12.76
37.60
12.53
T6
13.65
16.06
12.30
42.01
14.00
T7
15.57
11.72
14.68
41.97
13.99


Analysis of Variance








Source of
Degrees of
Sum of
Mean of
Computed TABULAR F
variation
freedom
squares
square
F
0.05
0.01










Replication
2
0.903
0.451

Treatment
6
100.201
16.700
8.95**
0.7888 0.0007
Error
12
22.379
1.865








TOTAL
20
123.483


** - highly significant



Coefficient of Variation = 10.97%





Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

37
Appendix Table 7. Non – marketable yield per plot (kg)


TREATMENT REPLICATIONS
I II III TOTAL MEAN






T1
3.35
2.75
2.27
8.37
2.79

T2
2.31
2.17
1.28
5.76
1.92
T3
1.94
2.09
2.35
6.38
2.13
T4
2.13
2.46
1.78
6.37
2.12
T5
2.21
2.52
2.15
6.88
2.29
T6
3.50
2.54
2.14
8.18
2.73
T7
3.16
2.42
2.17
7.75
2.58


Analysis of Variance








Source of
Degrees of
Sum of
Mean of
Computed TABULAR F
variation
freedom
squares
square
F
0.05
0.01










Replication
2
1.453
0.726

Treatment
6
2.032
0.339
2.45ns
0.0230 0.0881
Error
12
1.660
0.138








TOTAL
20
5.145


ns - not significant



Coefficient of Variation = 15.72%





Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

38
Appendix Table 8. Total yield per plot (kg)


TREATMENT REPLICATIONS
I II III TOTAL MEAN






T1
11.06
10.67
9.94
31.67
10.56

T2
17.69
15.46
16.64
49.79
16.60
T3
15.03
16.27
13.94
45.24
15.08
T4
13.85
13.56
12.68
40.09
13.36
T5
13.87
15.70
14.91
44.48
14.827
T6
17.15
18.60
14.44
50.19
16.73
T7
18.73
14.14
16.85
49.72
16.573


Analysis of Variance








Source of

Sum of
Mean of
Computed TABULAR F
variation
Degrees of
squares
square
F
0.05
0.01

freedom








Replication
2
4.646
2.323

Treatment
6
90.733
15.122
7.82**
0.3345 0.0014
Error
12
23.202
1.933








TOTAL
20
118.580


** - highly significant



Coefficient of Variation = 9.38%





Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

39
Appendix Table 9. Computed yield per hectare (t/ha)


TREATMENT REPLICATIONS
I II III TOTAL MEAN






T1
22.12
21.34
19.88
63.34
21.11

T2
35.38
30.92
33.28
99.58
33.19
T3
30.06
32.54
27.88
90.48
30.16
T4
27.70
27.12
25.36
80.18
26.73
T5
27.74
31.40
29.82
88.96
29.65
T6
34.30
37.20
28.88
100.38
33.46
T7
37.46
28.28
33.70
99.44
33.15



Analysis of Variance








Source of
Degrees of
Sum of
Mean of
Computed TABULAR F
variation
freedom
squares
square
F
0.05
0.01










Replication
2
18.583
9.292

Treatment
6
362.932
60.489
7.82**
0.33
0.00
Error
12
92.807
7.734








TOTAL
20
474.322


** - highly significant



Coefficient of Variation = 9.38%




Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

40
Appendix Table 10. Sugar content (January)


TREATMENT REPLICATIONS
I II III TOTAL MEAN






T1
7.60
5.00
7.00
19.60
6.53

T2
5.20
5.40
8.00
18.60
6.20
T3
5.00
6.80
7.00
18.80
6.27
T4
7.00
6.20
6.40
19.60
6.53
T5
6.00
7.00
6.20
19.20
6.40
T6
6.20
7.00
5.00
18.20
6.07
T7
6.00
5.00
6.20
17.20
5.73


Analysis of Variance








Source of
Degrees of
Sum of
Mean of
Computed TABULAR F
variation
freedom
squares
square
F
0.05
0.01










Replication
2
0.940
0.470

Treatment
6
1.459
0.243
0.21 ns
0.6738 0.9663
Error
12
13.832
1.153








TOTAL
20
16.232


ns - not significant



Coefficient of Variation = 17.18%





Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

41
Appendix Table 11. Sugar content (February)


TREATMENT REPLICATIONS
I II III TOTAL MEAN






T1
9.80
10.00
8.40
28.20
9.40

T2
8.00
8.60
8.60
25.20
8.40
T3
8.00
8.00
9.00
25.00
8.33
T4
8.60
8.40
8.00
25.00
8.33
T5
10.60
8.60
9.00
28.20
9.40
T6
9.60
9.40
12.00
31.00
10.33
T7
8.60
8.40
11.60
28.60
9.53


Analysis of Variance








Source of
Degrees of
Sum of
Mean of
Computed TABULAR F
variation
freedom
squares
square
F
0.05
0.01









Replication
2
1.992
0.996

Treatment
6
10.663
1.777
1.58ns
0.4372 0.2345
Error
12
13.474
1.123








TOTAL
20
26.130


ns - not significant



Coefficient of Variation = 11.64%





Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

42
Appendix Table 12. Sugar content (March)


TREATMENT REPLICATIONS
I II III TOTAL MEAN






T1
7.00
7.00
7.40
21.40
7.13

T2
10.00
10.40
9.00
29.40
9.80
T3
10.00
10.60
8.80
29.40
9.80
T4
9.80
9.00
8.60
27.40
9.13
T5
9.00
7.70
12.00
28.70
9.57
T6
10.00
9.80
9.40
29.20
9.73
T7
9.40
10.00
10.40
29.80
9.93


Analysis of Variance








Source of
Degrees of
Sum of
Mean of
Computed TABULAR F
variation
freedom
squares
square
F
0.05
0.01










Replication
2
0.089
0.044

Treatment
6
17.647
2.941
2.54*
0.9626 0.0800
Error
12
13.905
1.159








TOTAL
20
31.640


* - significant




Coefficient of Variation = 11.57%





Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

43
Appendix Table 13. Incidence of insect pest (strawberry mites)


TREATMENT REPLICATIONS
I II III TOTAL MEAN






T1
2.00
2.00
2.00
5.00
2.00

T2
2.00
1.00
1.00
4.00
1.33
T3
2.00
1.00
2.00
5.00
1.67
T4
2.00
2.00
3.00
7.00
2.33
T5
2.00
2.00
2.00
6.00
2.00
T6
1.00
2.00
2.00
5.00
1.67
T7
1.00
2.00
2.00
5.00
1.67


Analysis of Variance








Source of
Degrees of
Sum of
Mean of
Computed TABULAR F
variation
freedom
squares
square
F
0.05
0.01










Replication
2
0.381
0.190

Treatment
6
1.905
0.317
1.29ns
0.4828 0.3320
Error
12
2.952
0.246








TOTAL
20
5.238




ns - not significant



Coefficient of Variation = 27.41%



Effect of Various Colors of Polyethylene on the Growth
and Yield of Strawberry / Emmanuel T. Arañas. 2008

---

Document Outline

• Effect of Various Colors ofPolyethylene on the Growth and Yield of Strawberry
  • BIBLIOGRAPHY
  • ABSTRACT
  • TABLE OF CONTENTS
  • INTRODUCTION
  • REVIEW OF LITERATURE
  • MATERIALS AND METHODS
  • RESULTS AND DISCUSSIONS
    • Days to First Flower Appearance
    • Days from Transplanting to First Harvest
    • Days from Transplanting to Last Harvest
    • Percentage of Fruit Set
    • Percentage of Abnormal Fruit
    • Marketable Yield per Plot (kg)
    • Non � Marketable Yield per Plot (kg)
    • Total Yield per Plot (kg)
    • Computed Yield per Hectare (t/ha)
    • Taste Test
    • Monthly Sugar Content
    • Cost and Return Analysis
    • Other observation
  • SUMMARY, CONCLUSION AND RECOMMENDATION
    • Summary
    • Conclusion
    • Recommendation
  • LITERATURE CITED
  • APPENDICES

---