BIBLIOGRAPHY SOPOSOP, JACQUELINE G. APRIL...
BIBLIOGRAPHY
SOPOSOP, JACQUELINE G. APRIL 2012. Acceleration of Flowering of Aerial
Grown Strawberry ‘Sweet Charlie’ as Affected by Gibberellic Acid (GA3) Application
under Glasshouse Condition. Benguet State University, La Trinidad, Benguet.
Adviser: Franklin G. Bawang, MSc
ABSTRACT
The study was conducted at the Pomology Project Glasshouse, Benguet State
University, La Trinidad, Benguet from November 2011 to February 2012 to determine the
effect of gibberellic acid (GA3) on the flowering of strawberry, determine the best
concentrations and frequency of GA3 application that accelerated flowering of strawberry
and to compare bench and aerial techniques in planting strawberry to increase production
without utilizing wide land areas.
The Strawberry plants were applied once, two times, and three times with
Gibberellic Acid (GA3) at the concentrations of 0, 50, 100, 150, 200, and 250 ppm GA3 at
10 days interval 20 days from plating in a black polyethylene plastic bags with garden soil
and BSU compost (2:1) as growing media.
Results showed that the earliest plants to initiate flower buds were the plants treated
with 50 ppm GA3 and those plants applied once with the same GA3 concentration were the
first to attain red ripe stage from fruit set and had the earliest fruits that were harvested
(75% ripe) from planting.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
On the number of days from flower bud formation to fruit set, the plants that were
not treated with GA3 were the earliest to show fruit set and also had the earliest fruits
harvested from flower bud formation compared to the treated plants. The plants also
produced the highest total yield.
Among the plants treated with GA3, plants treated with 50 ppm GA3 applied two
(2) and three (3) times produced the highest yield followed by the plants treated with 100
ppm and 150 ppm GA3 applied three (3) times respectively.
Based on the preceding results and discussions, it is recommended not to use
gibberellic acid (GA3) in aerial planting of strawberry plants for higher production.
However, gibberellic acid (GA3) could be used for off-season production and
application of 50 ppm GA3 sprayed once 20 days from planting, is recommended to
improve and to enhance the flowering and fruiting of strawberry for earlier harvest.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
RESULTS AND DISCUSSION
Initial Height (cm)
Results showed that there were no significant differences obtained on the initial
height of strawberry plants 20 days from planting.
Number of Days from Planting to Flower Bud Formation
Effect of GA3 concentration. Highly significant differences were observed on the
number of days from planting to flower bud formation as affected by the different GA3
concentrations. Table 1 showed that plants treated with 50 ppm GA3 were the earliest to
initiate flower buds among the treatments with a mean of 38.44 days from planting but
were statistically comparable with the rest of the treatments applied with GA3. The plants
which were not applied with GA3 (control) took longer days to attain flower bud formation
from planting with a mean of 57.00 days.
Effect of frequency of application. Results showed that there were no significant
statistical differences observed on the number of days from planting to flower bud
formation as affected by the frequency of application. However, numerical figures showed
that the earliest to form flower buds were those plants applied with GA3 three (3) times
with a mean of 41.83 days followed by two (2) times application which had a mean of
42.67 days.
Interaction effect. There were highly significant interaction effects observed
between different GA3 concentrations and the frequency of application with regards to the
number of days from planting to flower bud formation.
Figure 1 showed that plants treated with 200 ppm GA3 applied once were the
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
earliest to initiate flower buds with a mean of 27.33 days compared to those plants treated
with the other concentrations applied two (2) and three (3) times. While those plants that
were not treated with GA3 but were applied with distilled water two (2) times (control) had
the longest number of days to initial flower bud formation with an average of 72.67 days
from planting.
Table 1. Number of days from planting to flower bud formation (0.5 cm bud size)
MEAN
TREATMENT
(days)
GA3 Concentration (ppm)
0 (Control)
57.00a
50
38.44b
100
41.89b
150
45.22b
200
42.56b
250
39.22b
Frequency of Application
1x
42.67a
2x
47.67a
3x
41.83a
Means with the same letter are not significantly different at 5% level by DMRT
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Figure 2. Number of days from planting to flower bud formation (0.5 cm bud size) of
strawberry as affected by concentration and frequency of GA3 application.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Number of Days from Flower Bud Formation to Fruit Set
Effect of GA3 concentration. Highly significant differences were observed on the
number of days from flower bud formation to fruit set. Table 2 showed that the earliest to
initiate fruit set among the plants treated with GA3 were those applied with 200 ppm with
a mean of 19.11 days while those plants applied with 250 ppm GA3 showed the highest
number of days with a mean of 23.56. Earlier fruit set were observed on plants which were
not applied with GA3 (control) with an average of 13.56 days compared to the plants treated
with different GA3 concentrations.
Effect of frequency of application. Results showed that there were no significant
differences on the number of days from flower bud formation to fruit set as affected by
frequency of application.
Interaction effect. There were no significant interaction effects observed between
the different GA3 concentrations and the frequency of application with regards to the
number of days from flower bud formation to fruit set.
Numerically, results showed that the plants treated with 200 ppm GA3 applied once
were the earliest to initiate fruit set with an average of 17.00 days from flower bud
formation followed by the plants treated with 50 ppm GA3 applied once and 200 ppm GA3
applied twice (2) with a mean of 18.00 and 19.00 days respectively. However, the plants
that were not treated with GA3 (control) were the earliest to initiate fruit set with a mean
of 9.67, 14.00 and 17.00 days from flower bud formation compared to those plants treated
with GA3 applied once, two (2) and three (3) times.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Table 2. Number of days from flower bud formation to fruit set
MEAN
TREATMENT
(days)
GA3 Concentration (ppm)
0 (Control)
13.56c
50
21.56ab
100
22.67ab
150
20.00ab
200
19.11b
250
23.56a
Frequency of Application
1x
19.56a
2x
20.17a
3x
20.50a
Means with the same letter are not significantly different at 5% DMRT
Number of Days from Fruit Set to Red Ripe Stage
Effect of GA3 concentration. No significant differences were observed on the
number of days from fruit set to red ripe stage as affected by different GA3 concentrations.
Numerically, results in table 3 showed that plants treated with 50 ppm were the earliest to
reach red ripe stage with an average of 20.67 days from fruit set compared to the other
treatments. While the plants treated with 100 ppm GA3 had the highest number of days to
attain red ripe stage with a mean of 32.22 days from fruit set.
Effect of frequency of application. Results showed that there were no significant
differences on the number of days from fruit to red ripe stage as affected by frequency of
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
application.
Interaction effect. There were no significant interaction effects observed between
the different GA3 concentrations and the frequency of application with regards to number
of days from fruit set to red ripe stage.
However, numerical results showed that plants treated with 50 ppm applied once
were the earliest to attain red ripe stage with a mean of 13.33 days from fruit set compared
to those plants treated with other concentration of GA3 applied two (2) and three (3) times.
Table 3. Number of days from fruit set to red ripe stage
MEAN
TREATMENT
(days)
GA3 Concentration (ppm)
0 (Control)
24.11a
50
20.67a
100
32.22a
150
24.67a
200
28.11a
250
30.11a
Frequency of Application
1x
25.06a
2x
28.39a
3x
26.50a
Means with the same letter are not significantly different at 5% level by DMRT
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Number of Days from Flower Bud Formation to First Fruit Harvest (red ripe stage)
Effect of GA3 concentration. Significant differences were observed on the number
of days from flower bud formation to first fruit harvest as affected by the different GA3
concentrations. Table 4 showed that plants treated with 50 ppm produced fruits that were
harvested earlier at red ripe stage with a mean of 45.11 days from flower bud formation
compared to the other plants treated with GA3. However, results revealed that the plants
without GA3 application (control) had the earliest fruits that were harvested at red ripe stage
with an average of 38.11 days from flower bud formation compared to the plants treated
with GA3.
Effect of frequency of application. Results showed that there were no significant
differences on the number of days from flower bud formation to first fruit harvest as
affected by frequency of application.
Interaction effect. There were no significant interaction effects observed between
the GA3 concentrations and the frequency of application with regards to number of days
from flower bud formation to first fruit harvest.
Numerically, results showed that plants treated with 150 ppm GA3 applied once had
the earliest fruits harvested at red ripe stage with an average of 41.33 days from flower bud
formation followed by plants treated with 50 ppm GA3 applied once with a mean of 41.67.
However, earlier fruit harvested at red ripe stage were observed from the plants that were
not applied with GA3 (control) with a mean of 36.33, 36.33 and 41.67 days from flower
bud formation compared to the plants treated with GA3.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Table 4. Number of days from flower bud formation to first fruit harvest (red ripe stage)
MEAN
TREATMENT
(days)
GA3 Concentration (ppm)
0 (Control)
38.11b
50
45.11ab
100
59.33a
150
54.33ab
200
62.67a
250
60.78a
Frequency of Application
1x
56.39a
2x
51.44a
3x
52.33a
Means with the same letters are not significantly different at 5% DMRT
Number of Days from Planting to First Fruit Harvest (75% red)
Effect of GA3 concentration. Table 5 shows that there were no significant
differences were observed on the number of days from planting to first fruit harvest as
affected by different GA3 concentrations. Numerically, results revealed that plants applied
with 50 ppm GA3 had the earliest fruits that were harvested at 75% red skin color with a
mean of 81.78 days from planting compared to the other treatments.
Effect of frequency of application. Results showed that there were no significant
differences recorded on the number of days from planting to first fruit harvest as affected
by frequency of application. However, results in table 5 showed that fruits of plants applied
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
once with GA3 were harvested earlier with a mean of 90.17 days from planting compared
to the plants applied with GA3 two (2) and three (3) times.
Interaction effect. There were no significant interaction effects noted between the
different GA3 concentrations and the frequency of application with regards to the number
of days from planting to first fruit harvest.
However, the results showed that plants treated with 50 ppm GA3 applied once,
produced the earliest fruits harvested at 75% red skin color from planting with a mean of
59.33 days compared to those plants treated with other GA3 concentrations applied two (2)
and three (3) times.
Table 5. Number of days from planting to first fruit harvest (75% red)
MEAN
TREATMENT
(days)
GA3 Concentration (ppm)
0 (Control)
100.78a
50
81.78a
100
102.44a
150
89.89a
200
104.00a
250
87.78a
Frequency of Application
1x
90.17a
2x
97.22a
3x
95.94a
Means with the same letter are not significantly different at 5% level by DMRT
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Total Yield (g)
Effect of GA3 concentration. Highly significant differences were observed on the
total yield of fruits harvested (g) from January to February. Plants applied with 50 ppm
GA3 had the highest average weight of fruits with a mean of 10.10 grams compared to the
other plants treated with different GA3 concentrations. However, plants that were not
treated with GA3 (control) had the highest average weight of fruits harvested with a mean
of 24.14 grams compared to the plants treated with different GA3 concentrations.
Effect of frequency of application. Results showed that there were no significant
differences on the total yield produced as affected by frequency of application.
Interaction effect. There were no significant interaction effect between the different
GA3 concentrations and the frequency of application with regards to total yield produced.
Numerically, results showed that plants treated with 50 ppm GA3 applied three (3)
and two (2) times have the highest total weight of fruits harvested with an average weight
of 11.08 and 11.49 grams respectively followed by the plants treated with 150 ppm GA3
applied three (3) times with a mean of 11.66 grams and the plants treated with 100 ppm
GA3 applied three (3) times with a mean of 11.84 grams compared to the other plants
treated with GA3. However, the plants that were not treated with GA3 (control) had the
highest total yield produced compared to the plants treated with different GA3
concentrations with an average weight of 26.19, 23.66 and 22.56 grams.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Table 6. Total yield (g)
TREATMENT
MEAN
GA3 Concentration (ppm)
0 (Control)
24.14a
50
10.10b
100
8.85b
150
6.98b
200
6.46b
250
0.84c
Frequency of Application
1x
8.84a
2x
9.22a
3x
10.63a
Means with the same letter are not significantly different at 5% level by DMRT
Marketable Yield (g)
Effect of GA3 concentration. Highly significant differences were observed on the
total marketable fruits as affected by different GA3 concentrations. Table 7 showed that the
plants treated with 50 ppm GA3 had the highest average weight of total marketable fruits
with a mean of 8.64 grams compared to those plants treated with different GA3
concentrations. However, plants that were not treated with GA3 (control) generally
produced higher total marketable yield with a mean of 19.24 grams while the plants treated
with 25 ppm GA3 produced the lowest average weight of total marketable fruits with a
mean of 0.22 grams.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Effect of frequency of application. Results showed that there were no significant
differences on total marketable fruits as affected by frequency of application.
Interaction effect. There were no significant interaction effects between different
GA3 concentrations and the frequency of application with regards to total marketable fruits.
Numerically, results showed that the plants treated with 150 ppm GA3 applied three
(3) times and the plants treated with 50 ppm GA3 applied two (2) times had the highest
weight of total marketable fruits compared to the other plants treated different GA3
concentrations applied once with a mean of 10.79 and 10.19 grams respectively. However,
the plants that were not treated with GA3 (control) generally had the highest weight of total
marketable fruits with a mean of 20.58, 18.85 and 18.29 grams compared to the plants
treated with GA3 as affected by different GA3 concentration and frequency of application.
Moreover, the plants treated with 250 ppm GA3 applied once and two (2) times did not
produce marketable fruits.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Table 7. Marketable yield (g)
TREATMENT
MEAN
GA3 Concentration (ppm)
0 (Control)
19.24a
50
8.69b
100
7.73b
150
5.45b
200
5.27b
250
0.22c
Frequency of Application
1x
6.98a
2x
7.49a
3x
8.81a
Means of the same letter are not significantly different at 5% level by DMRT
Non-marketable Yield (g)
Effect of GA3 concentration. Significant differences were observed on the total non-
marketable fruits as affected by different GA3 concentrations. Table 8 showed that the
plants treated with 150 ppm, 50 ppm, 200 ppm and 100 ppm GA3 had the highest weight
of non-marketable fruits with means of 1.53, 1.46, 1.18, and 1.12 grams compared to the
plants treated with 250 ppm GA3 with a mean of 0.62 grams. However, the plants that were
not treated with GA3 (control) produced the highest weight of total non-marketable fruits
with a mean of 4.896 grams.
Effect of frequency of application. Results showed that there were no significant
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
differences on total non-marketable fruits as affected by frequency of application.
Interaction effect. There were no significant interaction effects between the
different GA3 concentrations and the frequency of application with regards to the total non-
marketable fruits.
Numerically, results showed that the plants treated with 150 ppm GA3 applied three
(3) times and the plants treated with 200 ppm GA3 applied once had the highest total of
non-marketable fruits compared to the other plants treated with different GA3
concentrations with a mean of 2.54 and 2.15 grams respectively. However, the plants that
were not treated with GA3 have the highest weight of total non-marketable fruits with a
mean of 5.61, 5.37 and 3.71 grams compared to the plants treated with GA3.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Table 8. Non-marketable yield (g)
TREATMENT
MEAN
GA3 Concentration (ppm)
0 (Control)
4.89a
50
1.46b
100
1.12b
150
1.53b
200
1.18b
250
0.62b
Frequency of Application
1x
1.86a
2x
1.73a
3x
1.82a
Means of the same letter are not significantly different at 5% level by DMRT
Occurrence of Insect Pest and Diseases
Vegetative Stage. Moderate infestations and infection of insect pest and diseases
were observed on the plants planted at the bench and those plants that were hanged during
the vegetative stage.
Moreover, severe infestations of mites were observed on the plants planted on the
bench while moderate infestations were observed on the plants that were hanged during the
vegetative stage.
Reproductive Stage. There were moderate infestations of insects and there were no
disease infection observed on the plants planted on bench and those plants that were hanged
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
during the reproductive stage.
Moreover, moderate infestation of mites was observed on the plants planted on the
bench while there was no infestation noted on the plants that were hanged during the
reproductive stage.
Maturity Stage. There were no insect pests, mites infestation and disease infection
recorded on the fruits planted on the bench as well as those plants that were hanged during
the maturity stage.
Table 9. Occurrence of insect pest and diseases
INSECT
VEGETATIVE
REPRODUCTIVE
MATURITY STAGE
PEST AND
STAGE
STAGE
DISEASES BENCH
AERIAL
BENCH
AERIAL
BENCH
AERIAL
PLANT-
PLANT-
PLANT-
PLANT-
PLANT-
PLANT-
ING
ING
ING
ING
ING
ING
Insects
2
2
2
2
1
1
Diseases
3
3
1
1
1
1
Mites
3
2
2
1
1
1
Infestation
Insect pest infestation and disease infection rating:
1 – no infestation/ infection
2 – moderate infestation/ infection
3- severe infestation/ infection
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Sugar Content (% Brix)
Effect of GA3 concentration. Significant differences were observed on the percent
sugar contents of fruits as affected by different GA3 concentrations. Table 10 showed that
the plants treated with 150 ppm GA3 had sweeter fruits compared to the other treatments
with a mean of 7.88% followed by those plants that were not treated with GA3 (control)
with a mean of 7.09%.
Effect of frequency of application. Results showed that there were no significant
differences on the percent sugar content of fruits as affected by different frequency of
application.
Interaction effect. There were no significant interaction effects between the
different GA3 concentrations and the frequency of application with regards to percent sugar
content.
However, results showed that the plants treated with 150 ppm GA3 applied two (2)
and three (3) times were generally sweeter with a mean of 8.93% and 8.03% including the
plants treated with 100 ppm GA3 applied two (2) times with a mean of 8.37% compared to
the other treatments. Moreover, the plants treated with 250 ppm GA3 applied once and
twice have no percent sugar content because the fruits harvested have no juice extracted
due to small fruits.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Table 10. Sugar content (% Brix)
TREATMENT
MEAN
GA3 Concentration (ppm)
0 (Control)
7.09a
50
6.98a
100
6.53a
150
7.88a
200
6.28a
250
1.11b
Frequency of Application
1x
5.68a
2x
6.24a
3x
6.00a
Means of the same letter are not significantly different at 5% level by DMRT
Temperature Data (oC)
Table 11 presents the maximum temperature data recorded inside the glasshouse
from plating until harvesting.
There was a lower average temperature during the month of November and
February compared to the month of December and January however there were no big
differences regarding temperature during the 4 months duration of the experiment.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Table 11. Temperature data of the glasshouse
AVERAGE TEMPERATURE
MONTH
(oC)
November
20.79
December
21.98
January
21.39
February
20.88
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary
The study was conducted at the Pomology Project Glasshouse, Benguet State
University, La Trinidad, Benguet from November 2011 to February 2012 to determine the
effect of gibberellic acid (GA3) on the flowering of strawberry, determine the best
concentrations and frequency of GA3 application that accelerated flowering of strawberry
and to compare bench and aerial techniques in planting strawberry to increase production
without utilizing wide land areas.
The earliest plants to initiate flower buds were the plants treated with 50 ppm GA3
and those plants applied once with the same GA3 concentration were the first to attain red
ripe stage from fruit set and had the earliest fruits that were harvested (75% ripe) from
planting. This was followed by the plants treated with 200 ppm GA3 applied once and those
were also the earliest to show fruit set among the treated plants.
On the number of days from flower bud formation to fruit set, the plants that were
not treated with GA3 (control) were the earliest to show fruit set and also had the earliest
fruits harvested from flower bud formation compared to the treated plants. The plants also
produced the highest total weight of fruits with the highest marketable and non-marketable
yield.
Among the plants treated with GA3, plants treated with 50 ppm GA3 applied two
(2) and three (3) times produced the highest yield followed by the plants treated with 100
ppm and 150 ppm GA3 applied three (3) times respectively. Moreover, the plants treated
with 150 ppm and 50 ppm GA3 applied three (3) and two (2) times respectively had the
highest marketable yield while the plants treated with 250 ppm GA3 applied once and two
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
(2) times did not produce marketable fruits. With regards to non-marketable fruits, the
plants treated with 150 ppm and 200 ppm GA3 applied three (3) times and once were the
highest in terms of weight.
As to percent sugar content, the plants treated with 150 ppm GA3 applied two (2)
and three (3) times, the plants treated with 100 ppm GA3 applied two (2) times and those
plants that were not treated with GA3 were the sweetest among the other treatments.
With regards to occurrence of insect pest and diseases, both the plants planted on
bench and plants that were hanged are comparable from vegetative stage until maturity
stage. However, mites infestation was moderately observed on the plants planted on the
bench while the plants that were hanged had no infestation during the reproductive stage.
On the temperature data, there was a lower average temperature during the month
of November and February compared to the month of December and January; however
there were no big differences during the four (4) months.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Conclusion
It is therefore concluded that the strawberry plants not treated with gibberellic acid
(GA3) were the first to fruit set from flower bud formation, the first to be harvested at red
ripe stage and produced higher yield than those treated plants. It is also concluded that 50
ppm GA3 application enhances flower bud formation, fruit development from fruit set to
red ripe stage and first to be harvested from planting.
Recommendation
Based on the preceding results and discussions, it is recommended not to use
gibberellic acid (GA3) in aerial planting of strawberry plants for higher production during
the usual cropping season.
However, gibberellic acid (GA3) could be used for off-season production and application
of 50 ppm GA3 sprayed once 20 days from planting is recommended to improve and to
enhance the flowering and fruiting of strawberry for earlier harvest.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
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CUTTING, J. G. 1997. Use of Gibberellic Acid to Manipulate Flowering in the 'Hass'
Avocado: A Preliminary Report. Federation, Inc. and NZ Avocado Growers Association,
Inc. Pp. 106-111.
DEVLIN, R. M. 1977. Plant Physiology. Van Nostrand Reinhold Co. New York. Pp. 387-
484.
DEVLIN, R. M. 1983. Plant Physiology (4th Edition). National Bookstore. Rizal
Avenue, Manila. Pp. 478-494.
EDMUND, J. B., T. L. SENN and F. S. ANDREWS. 1975. Fundamentals of Horticulture.
Interline Printing Inc.. Quezon City. Pp. 401- 404.
GALINGAN, A. C. 1977. Growth and Flowering of Five Lilium Cutflowers as Affected
by GA3 Application BS Thesis. Benguet State University, La Trinidad, Benguet. Pp. 3-5.
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New York. Pp. 488-489.
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HERMANO, F. G. 1999. Strawberry Production Management and Technology. ELIJAH
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Introductions Using Mother Plants and Runners Chilled at Various Duration Planted
During off – season Under Greenhouse in La Trinidad, Benguet. Ph.D. Dissertation. BSU,
La Trinidad, Benguet. Pp. 1–106.
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Moriflorium) as affected by gibberellic acid and frequency of application MS Thesis.
Benguet State University. La Trinidad, Benguet. Pp. 4-7.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
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Edition). McGrawHill Book Co.. New York. Pp. 230-233.
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Plants and Animals: An Introduction. Wiley London, New York. P. 284.
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Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
SOPOSOP, JACQUELINE G. APRIL 2012. Acceleration of Flowering of Aerial
Grown Strawberry ‘Sweet Charlie’ as Affected by Gibberellic Acid (GA3) Application
under Glasshouse Condition. Benguet State University, La Trinidad, Benguet.
Adviser: Franklin G. Bawang, MSc
ABSTRACT
The study was conducted at the Pomology Project Glasshouse, Benguet State
University, La Trinidad, Benguet from November 2011 to February 2012 to determine the
effect of gibberellic acid (GA3) on the flowering of strawberry, determine the best
concentrations and frequency of GA3 application that accelerated flowering of strawberry
and to compare bench and aerial techniques in planting strawberry to increase production
without utilizing wide land areas.
The Strawberry plants were applied once, two times, and three times with
Gibberellic Acid (GA3) at the concentrations of 0, 50, 100, 150, 200, and 250 ppm GA3 at
10 days interval 20 days from plating in a black polyethylene plastic bags with garden soil
and BSU compost (2:1) as growing media.
Results showed that the earliest plants to initiate flower buds were the plants treated
with 50 ppm GA3 and those plants applied once with the same GA3 concentration were the
first to attain red ripe stage from fruit set and had the earliest fruits that were harvested
(75% ripe) from planting.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
On the number of days from flower bud formation to fruit set, the plants that were
not treated with GA3 were the earliest to show fruit set and also had the earliest fruits
harvested from flower bud formation compared to the treated plants. The plants also
produced the highest total yield.
Among the plants treated with GA3, plants treated with 50 ppm GA3 applied two
(2) and three (3) times produced the highest yield followed by the plants treated with 100
ppm and 150 ppm GA3 applied three (3) times respectively.
Based on the preceding results and discussions, it is recommended not to use
gibberellic acid (GA3) in aerial planting of strawberry plants for higher production.
However, gibberellic acid (GA3) could be used for off-season production and
application of 50 ppm GA3 sprayed once 20 days from planting, is recommended to
improve and to enhance the flowering and fruiting of strawberry for earlier harvest.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
RESULTS AND DISCUSSION
Initial Height (cm)
Results showed that there were no significant differences obtained on the initial
height of strawberry plants 20 days from planting.
Number of Days from Planting to Flower Bud Formation
Effect of GA3 concentration. Highly significant differences were observed on the
number of days from planting to flower bud formation as affected by the different GA3
concentrations. Table 1 showed that plants treated with 50 ppm GA3 were the earliest to
initiate flower buds among the treatments with a mean of 38.44 days from planting but
were statistically comparable with the rest of the treatments applied with GA3. The plants
which were not applied with GA3 (control) took longer days to attain flower bud formation
from planting with a mean of 57.00 days.
Effect of frequency of application. Results showed that there were no significant
statistical differences observed on the number of days from planting to flower bud
formation as affected by the frequency of application. However, numerical figures showed
that the earliest to form flower buds were those plants applied with GA3 three (3) times
with a mean of 41.83 days followed by two (2) times application which had a mean of
42.67 days.
Interaction effect. There were highly significant interaction effects observed
between different GA3 concentrations and the frequency of application with regards to the
number of days from planting to flower bud formation.
Figure 1 showed that plants treated with 200 ppm GA3 applied once were the
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
earliest to initiate flower buds with a mean of 27.33 days compared to those plants treated
with the other concentrations applied two (2) and three (3) times. While those plants that
were not treated with GA3 but were applied with distilled water two (2) times (control) had
the longest number of days to initial flower bud formation with an average of 72.67 days
from planting.
Table 1. Number of days from planting to flower bud formation (0.5 cm bud size)
MEAN
TREATMENT
(days)
GA3 Concentration (ppm)
0 (Control)
57.00a
50
38.44b
100
41.89b
150
45.22b
200
42.56b
250
39.22b
Frequency of Application
1x
42.67a
2x
47.67a
3x
41.83a
Means with the same letter are not significantly different at 5% level by DMRT
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Figure 2. Number of days from planting to flower bud formation (0.5 cm bud size) of
strawberry as affected by concentration and frequency of GA3 application.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Number of Days from Flower Bud Formation to Fruit Set
Effect of GA3 concentration. Highly significant differences were observed on the
number of days from flower bud formation to fruit set. Table 2 showed that the earliest to
initiate fruit set among the plants treated with GA3 were those applied with 200 ppm with
a mean of 19.11 days while those plants applied with 250 ppm GA3 showed the highest
number of days with a mean of 23.56. Earlier fruit set were observed on plants which were
not applied with GA3 (control) with an average of 13.56 days compared to the plants treated
with different GA3 concentrations.
Effect of frequency of application. Results showed that there were no significant
differences on the number of days from flower bud formation to fruit set as affected by
frequency of application.
Interaction effect. There were no significant interaction effects observed between
the different GA3 concentrations and the frequency of application with regards to the
number of days from flower bud formation to fruit set.
Numerically, results showed that the plants treated with 200 ppm GA3 applied once
were the earliest to initiate fruit set with an average of 17.00 days from flower bud
formation followed by the plants treated with 50 ppm GA3 applied once and 200 ppm GA3
applied twice (2) with a mean of 18.00 and 19.00 days respectively. However, the plants
that were not treated with GA3 (control) were the earliest to initiate fruit set with a mean
of 9.67, 14.00 and 17.00 days from flower bud formation compared to those plants treated
with GA3 applied once, two (2) and three (3) times.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
Table 2. Number of days from flower bud formation to fruit set
MEAN
TREATMENT
(days)
GA3 Concentration (ppm)
0 (Control)
13.56c
50
21.56ab
100
22.67ab
150
20.00ab
200
19.11b
250
23.56a
Frequency of Application
1x
19.56a
2x
20.17a
3x
20.50a
Means with the same letter are not significantly different at 5% DMRT
Number of Days from Fruit Set to Red Ripe Stage
Effect of GA3 concentration. No significant differences were observed on the
number of days from fruit set to red ripe stage as affected by different GA3 concentrations.
Numerically, results in table 3 showed that plants treated with 50 ppm were the earliest to
reach red ripe stage with an average of 20.67 days from fruit set compared to the other
treatments. While the plants treated with 100 ppm GA3 had the highest number of days to
attain red ripe stage with a mean of 32.22 days from fruit set.
Effect of frequency of application. Results showed that there were no significant
differences on the number of days from fruit to red ripe stage as affected by frequency of
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
application.
Interaction effect. There were no significant interaction effects observed between
the different GA3 concentrations and the frequency of application with regards to number
of days from fruit set to red ripe stage.
However, numerical results showed that plants treated with 50 ppm applied once
were the earliest to attain red ripe stage with a mean of 13.33 days from fruit set compared
to those plants treated with other concentration of GA3 applied two (2) and three (3) times.
Table 3. Number of days from fruit set to red ripe stage
MEAN
TREATMENT
(days)
GA3 Concentration (ppm)
0 (Control)
24.11a
50
20.67a
100
32.22a
150
24.67a
200
28.11a
250
30.11a
Frequency of Application
1x
25.06a
2x
28.39a
3x
26.50a
Means with the same letter are not significantly different at 5% level by DMRT
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
Number of Days from Flower Bud Formation to First Fruit Harvest (red ripe stage)
Effect of GA3 concentration. Significant differences were observed on the number
of days from flower bud formation to first fruit harvest as affected by the different GA3
concentrations. Table 4 showed that plants treated with 50 ppm produced fruits that were
harvested earlier at red ripe stage with a mean of 45.11 days from flower bud formation
compared to the other plants treated with GA3. However, results revealed that the plants
without GA3 application (control) had the earliest fruits that were harvested at red ripe stage
with an average of 38.11 days from flower bud formation compared to the plants treated
with GA3.
Effect of frequency of application. Results showed that there were no significant
differences on the number of days from flower bud formation to first fruit harvest as
affected by frequency of application.
Interaction effect. There were no significant interaction effects observed between
the GA3 concentrations and the frequency of application with regards to number of days
from flower bud formation to first fruit harvest.
Numerically, results showed that plants treated with 150 ppm GA3 applied once had
the earliest fruits harvested at red ripe stage with an average of 41.33 days from flower bud
formation followed by plants treated with 50 ppm GA3 applied once with a mean of 41.67.
However, earlier fruit harvested at red ripe stage were observed from the plants that were
not applied with GA3 (control) with a mean of 36.33, 36.33 and 41.67 days from flower
bud formation compared to the plants treated with GA3.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
Table 4. Number of days from flower bud formation to first fruit harvest (red ripe stage)
MEAN
TREATMENT
(days)
GA3 Concentration (ppm)
0 (Control)
38.11b
50
45.11ab
100
59.33a
150
54.33ab
200
62.67a
250
60.78a
Frequency of Application
1x
56.39a
2x
51.44a
3x
52.33a
Means with the same letters are not significantly different at 5% DMRT
Number of Days from Planting to First Fruit Harvest (75% red)
Effect of GA3 concentration. Table 5 shows that there were no significant
differences were observed on the number of days from planting to first fruit harvest as
affected by different GA3 concentrations. Numerically, results revealed that plants applied
with 50 ppm GA3 had the earliest fruits that were harvested at 75% red skin color with a
mean of 81.78 days from planting compared to the other treatments.
Effect of frequency of application. Results showed that there were no significant
differences recorded on the number of days from planting to first fruit harvest as affected
by frequency of application. However, results in table 5 showed that fruits of plants applied
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
once with GA3 were harvested earlier with a mean of 90.17 days from planting compared
to the plants applied with GA3 two (2) and three (3) times.
Interaction effect. There were no significant interaction effects noted between the
different GA3 concentrations and the frequency of application with regards to the number
of days from planting to first fruit harvest.
However, the results showed that plants treated with 50 ppm GA3 applied once,
produced the earliest fruits harvested at 75% red skin color from planting with a mean of
59.33 days compared to those plants treated with other GA3 concentrations applied two (2)
and three (3) times.
Table 5. Number of days from planting to first fruit harvest (75% red)
MEAN
TREATMENT
(days)
GA3 Concentration (ppm)
0 (Control)
100.78a
50
81.78a
100
102.44a
150
89.89a
200
104.00a
250
87.78a
Frequency of Application
1x
90.17a
2x
97.22a
3x
95.94a
Means with the same letter are not significantly different at 5% level by DMRT
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
Total Yield (g)
Effect of GA3 concentration. Highly significant differences were observed on the
total yield of fruits harvested (g) from January to February. Plants applied with 50 ppm
GA3 had the highest average weight of fruits with a mean of 10.10 grams compared to the
other plants treated with different GA3 concentrations. However, plants that were not
treated with GA3 (control) had the highest average weight of fruits harvested with a mean
of 24.14 grams compared to the plants treated with different GA3 concentrations.
Effect of frequency of application. Results showed that there were no significant
differences on the total yield produced as affected by frequency of application.
Interaction effect. There were no significant interaction effect between the different
GA3 concentrations and the frequency of application with regards to total yield produced.
Numerically, results showed that plants treated with 50 ppm GA3 applied three (3)
and two (2) times have the highest total weight of fruits harvested with an average weight
of 11.08 and 11.49 grams respectively followed by the plants treated with 150 ppm GA3
applied three (3) times with a mean of 11.66 grams and the plants treated with 100 ppm
GA3 applied three (3) times with a mean of 11.84 grams compared to the other plants
treated with GA3. However, the plants that were not treated with GA3 (control) had the
highest total yield produced compared to the plants treated with different GA3
concentrations with an average weight of 26.19, 23.66 and 22.56 grams.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
Table 6. Total yield (g)
TREATMENT
MEAN
GA3 Concentration (ppm)
0 (Control)
24.14a
50
10.10b
100
8.85b
150
6.98b
200
6.46b
250
0.84c
Frequency of Application
1x
8.84a
2x
9.22a
3x
10.63a
Means with the same letter are not significantly different at 5% level by DMRT
Marketable Yield (g)
Effect of GA3 concentration. Highly significant differences were observed on the
total marketable fruits as affected by different GA3 concentrations. Table 7 showed that the
plants treated with 50 ppm GA3 had the highest average weight of total marketable fruits
with a mean of 8.64 grams compared to those plants treated with different GA3
concentrations. However, plants that were not treated with GA3 (control) generally
produced higher total marketable yield with a mean of 19.24 grams while the plants treated
with 25 ppm GA3 produced the lowest average weight of total marketable fruits with a
mean of 0.22 grams.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Effect of frequency of application. Results showed that there were no significant
differences on total marketable fruits as affected by frequency of application.
Interaction effect. There were no significant interaction effects between different
GA3 concentrations and the frequency of application with regards to total marketable fruits.
Numerically, results showed that the plants treated with 150 ppm GA3 applied three
(3) times and the plants treated with 50 ppm GA3 applied two (2) times had the highest
weight of total marketable fruits compared to the other plants treated different GA3
concentrations applied once with a mean of 10.79 and 10.19 grams respectively. However,
the plants that were not treated with GA3 (control) generally had the highest weight of total
marketable fruits with a mean of 20.58, 18.85 and 18.29 grams compared to the plants
treated with GA3 as affected by different GA3 concentration and frequency of application.
Moreover, the plants treated with 250 ppm GA3 applied once and two (2) times did not
produce marketable fruits.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
Table 7. Marketable yield (g)
TREATMENT
MEAN
GA3 Concentration (ppm)
0 (Control)
19.24a
50
8.69b
100
7.73b
150
5.45b
200
5.27b
250
0.22c
Frequency of Application
1x
6.98a
2x
7.49a
3x
8.81a
Means of the same letter are not significantly different at 5% level by DMRT
Non-marketable Yield (g)
Effect of GA3 concentration. Significant differences were observed on the total non-
marketable fruits as affected by different GA3 concentrations. Table 8 showed that the
plants treated with 150 ppm, 50 ppm, 200 ppm and 100 ppm GA3 had the highest weight
of non-marketable fruits with means of 1.53, 1.46, 1.18, and 1.12 grams compared to the
plants treated with 250 ppm GA3 with a mean of 0.62 grams. However, the plants that were
not treated with GA3 (control) produced the highest weight of total non-marketable fruits
with a mean of 4.896 grams.
Effect of frequency of application. Results showed that there were no significant
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
differences on total non-marketable fruits as affected by frequency of application.
Interaction effect. There were no significant interaction effects between the
different GA3 concentrations and the frequency of application with regards to the total non-
marketable fruits.
Numerically, results showed that the plants treated with 150 ppm GA3 applied three
(3) times and the plants treated with 200 ppm GA3 applied once had the highest total of
non-marketable fruits compared to the other plants treated with different GA3
concentrations with a mean of 2.54 and 2.15 grams respectively. However, the plants that
were not treated with GA3 have the highest weight of total non-marketable fruits with a
mean of 5.61, 5.37 and 3.71 grams compared to the plants treated with GA3.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
Table 8. Non-marketable yield (g)
TREATMENT
MEAN
GA3 Concentration (ppm)
0 (Control)
4.89a
50
1.46b
100
1.12b
150
1.53b
200
1.18b
250
0.62b
Frequency of Application
1x
1.86a
2x
1.73a
3x
1.82a
Means of the same letter are not significantly different at 5% level by DMRT
Occurrence of Insect Pest and Diseases
Vegetative Stage. Moderate infestations and infection of insect pest and diseases
were observed on the plants planted at the bench and those plants that were hanged during
the vegetative stage.
Moreover, severe infestations of mites were observed on the plants planted on the
bench while moderate infestations were observed on the plants that were hanged during the
vegetative stage.
Reproductive Stage. There were moderate infestations of insects and there were no
disease infection observed on the plants planted on bench and those plants that were hanged
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
during the reproductive stage.
Moreover, moderate infestation of mites was observed on the plants planted on the
bench while there was no infestation noted on the plants that were hanged during the
reproductive stage.
Maturity Stage. There were no insect pests, mites infestation and disease infection
recorded on the fruits planted on the bench as well as those plants that were hanged during
the maturity stage.
Table 9. Occurrence of insect pest and diseases
INSECT
VEGETATIVE
REPRODUCTIVE
MATURITY STAGE
PEST AND
STAGE
STAGE
DISEASES BENCH
AERIAL
BENCH
AERIAL
BENCH
AERIAL
PLANT-
PLANT-
PLANT-
PLANT-
PLANT-
PLANT-
ING
ING
ING
ING
ING
ING
Insects
2
2
2
2
1
1
Diseases
3
3
1
1
1
1
Mites
3
2
2
1
1
1
Infestation
Insect pest infestation and disease infection rating:
1 – no infestation/ infection
2 – moderate infestation/ infection
3- severe infestation/ infection
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
Sugar Content (% Brix)
Effect of GA3 concentration. Significant differences were observed on the percent
sugar contents of fruits as affected by different GA3 concentrations. Table 10 showed that
the plants treated with 150 ppm GA3 had sweeter fruits compared to the other treatments
with a mean of 7.88% followed by those plants that were not treated with GA3 (control)
with a mean of 7.09%.
Effect of frequency of application. Results showed that there were no significant
differences on the percent sugar content of fruits as affected by different frequency of
application.
Interaction effect. There were no significant interaction effects between the
different GA3 concentrations and the frequency of application with regards to percent sugar
content.
However, results showed that the plants treated with 150 ppm GA3 applied two (2)
and three (3) times were generally sweeter with a mean of 8.93% and 8.03% including the
plants treated with 100 ppm GA3 applied two (2) times with a mean of 8.37% compared to
the other treatments. Moreover, the plants treated with 250 ppm GA3 applied once and
twice have no percent sugar content because the fruits harvested have no juice extracted
due to small fruits.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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SOPOSOP, JACQUELINE G. APRIL 2012
Table 10. Sugar content (% Brix)
TREATMENT
MEAN
GA3 Concentration (ppm)
0 (Control)
7.09a
50
6.98a
100
6.53a
150
7.88a
200
6.28a
250
1.11b
Frequency of Application
1x
5.68a
2x
6.24a
3x
6.00a
Means of the same letter are not significantly different at 5% level by DMRT
Temperature Data (oC)
Table 11 presents the maximum temperature data recorded inside the glasshouse
from plating until harvesting.
There was a lower average temperature during the month of November and
February compared to the month of December and January however there were no big
differences regarding temperature during the 4 months duration of the experiment.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
Table 11. Temperature data of the glasshouse
AVERAGE TEMPERATURE
MONTH
(oC)
November
20.79
December
21.98
January
21.39
February
20.88
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
Gibberellic Acid (GA3) Application under Glasshouse Condition |
SOPOSOP, JACQUELINE G. APRIL 2012
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary
The study was conducted at the Pomology Project Glasshouse, Benguet State
University, La Trinidad, Benguet from November 2011 to February 2012 to determine the
effect of gibberellic acid (GA3) on the flowering of strawberry, determine the best
concentrations and frequency of GA3 application that accelerated flowering of strawberry
and to compare bench and aerial techniques in planting strawberry to increase production
without utilizing wide land areas.
The earliest plants to initiate flower buds were the plants treated with 50 ppm GA3
and those plants applied once with the same GA3 concentration were the first to attain red
ripe stage from fruit set and had the earliest fruits that were harvested (75% ripe) from
planting. This was followed by the plants treated with 200 ppm GA3 applied once and those
were also the earliest to show fruit set among the treated plants.
On the number of days from flower bud formation to fruit set, the plants that were
not treated with GA3 (control) were the earliest to show fruit set and also had the earliest
fruits harvested from flower bud formation compared to the treated plants. The plants also
produced the highest total weight of fruits with the highest marketable and non-marketable
yield.
Among the plants treated with GA3, plants treated with 50 ppm GA3 applied two
(2) and three (3) times produced the highest yield followed by the plants treated with 100
ppm and 150 ppm GA3 applied three (3) times respectively. Moreover, the plants treated
with 150 ppm and 50 ppm GA3 applied three (3) and two (2) times respectively had the
highest marketable yield while the plants treated with 250 ppm GA3 applied once and two
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(2) times did not produce marketable fruits. With regards to non-marketable fruits, the
plants treated with 150 ppm and 200 ppm GA3 applied three (3) times and once were the
highest in terms of weight.
As to percent sugar content, the plants treated with 150 ppm GA3 applied two (2)
and three (3) times, the plants treated with 100 ppm GA3 applied two (2) times and those
plants that were not treated with GA3 were the sweetest among the other treatments.
With regards to occurrence of insect pest and diseases, both the plants planted on
bench and plants that were hanged are comparable from vegetative stage until maturity
stage. However, mites infestation was moderately observed on the plants planted on the
bench while the plants that were hanged had no infestation during the reproductive stage.
On the temperature data, there was a lower average temperature during the month
of November and February compared to the month of December and January; however
there were no big differences during the four (4) months.
Acceleration of Flowering of Aerial Grown Strawberry ‘Sweet Charlie’ as Affected by
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Conclusion
It is therefore concluded that the strawberry plants not treated with gibberellic acid
(GA3) were the first to fruit set from flower bud formation, the first to be harvested at red
ripe stage and produced higher yield than those treated plants. It is also concluded that 50
ppm GA3 application enhances flower bud formation, fruit development from fruit set to
red ripe stage and first to be harvested from planting.
Recommendation
Based on the preceding results and discussions, it is recommended not to use
gibberellic acid (GA3) in aerial planting of strawberry plants for higher production during
the usual cropping season.
However, gibberellic acid (GA3) could be used for off-season production and application
of 50 ppm GA3 sprayed once 20 days from planting is recommended to improve and to
enhance the flowering and fruiting of strawberry for earlier harvest.
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