Influence of paclobutrazol on growth, yield and quality of mango

Abstract

p>A study on the effect of paclobutrazol on vegetative growth, harvest time, yield and quality of mango cv. BARI Mango-3 (Amrapali) was conducted at the Germplasm Centre, Department of Horticulture, Bangladesh Agricultural University, Mymensingh. Paclobutrazol @ 7500 ppm, 10000 ppm and control (water application) along with two application times; 15 July and 15 October were used with three replications following RCBD design. Paclobutrazol soil drenched @ 7500 ppm or 10000 ppm on 15 July distinctly advanced panicle emergence and fruit harvest by 23 and 22 days, respectively. Application of paclobutrazol @ 7500 ppm on 15 July produced the highest number of fruits (185) as well as yield (55.05 kg) per plant and the biggest fruit (303.67 g). Paclobutrazol @ 7500 ppm applied on 15 July or 15 October also resulted in higher edible portion, lower stone pulp ratio, longer shelf life, higher TSS, increased vitamin C, lower titratable acidity, higher dry matter, reducing, non-reducing and total sugar contents.

Bangladesh J. Agril. Res. 43(1): 1-12, March 2018</p

Full text

ISSN 0258-7122 (Print), 2408-8293 (Online)
Bangladesh J. Agril. Res. 43(1): 1-12, March 2018
INFLUENCE OF PACLOBUTRAZOL ON GROWTH, YIELD AND
QUALITY OF MANGO
B. C. SARKER
1
AND M. A. RAHIM2
Abstract
A study on the effect of paclobutrazol on vegetative growth, harvest time, yield
and quality of mango cv. BARI Mango-3 (Amrapali) was conducted at the
Germplasm Centre, Department of Horticulture, Bangladesh Agricultural
University, Mymensingh. Paclobutrazol @ 7500 ppm, 10000 ppm and control
(water application) along with two application times; 15 July and 15 October
were used with three replications following RCBD design. Paclobutrazol soil
drenched @ 7500 ppm or 10000 ppm on 15 July distinctly advanced panicle
emergence and fruit harvest by 23 and 22 days, respectively. Application of
paclobutrazol @ 7500 ppm on 15 July produced the highest number of fruits
(185) as well as yield (55.05 kg) per plant and the biggest fruit (303.67 g).
Paclobutrazol @ 7500 ppm applied on 15 July or 15 October also resulted in
higher edible portion, lower stone pulp ratio, longer shelf life, higher TSS,
increased vitamin C, lower titratable acidity, higher dry matter, reducing, non-
reducing and total sugar contents.
Keywords: Paclobutrazol, panicle emergence, fruit retention, edible portion, yield
and quality.
Introduction
Mango (Mangifera indica L.), the king of fruits, predominantly grows in a short
harvest period from May to June in Bangladesh. Irregular flowering, low fruit set
as well as retention leading to low yield and fruits of poor quality are also the
prevalent problems in mango production. The availability of fresh fruits after the
normal fruiting season for a longer period, in addition to increasing yield and
quality can be extended by using paclobutrazol. Soil application of paclobutrazol
induces precocious flowering in young trees and promotes early flowering in
bearing trees (Kulkarni, 1988). Inflorescence becomes visible within 2.5 to 4
months after the application of paclobutrazol depending on cultivar (Junthasri et
al., 2000). PP333 (paclobutrazol) enhances the flower and fruit production in
mango (Anbu et al., 2002). Improvement of fruit set and fruit retention in mango
cv. Gulab Khas as well as the highest yield had been noticed under soil
application of paclobutrazol (Singh and Singh, 2006). Paclobutrazol exhibits the
pronounced effect on increasing the parameters like ascorbic acid, total sugar,
reducing sugar and TSS, except for acidity in fruits of Alphonso mangoes at
1
Principal Scientific Officer, Pomology Division, Horticulture Research Centre,
Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur & Former
Fulbright Visiting Scholar, 2Professor, Department of Horticulture, Bangladesh
Agriculture University (BAU), Mymensingh, Bangladesh.

2 SARKER AND RAHIM
Coimbatore, India (Vijayalakshmi and Srinivasan, 2000). Mango trees treated
with paclobutrazol had higher results for number of panicles produced, yield as
well as quality of fruit compared to control (Yeshitela et al., 2004). Information
regarding regulation of flowering and harvesting time, increasing yield and
quality of mango using paclobutrazol is little or nil in Bangladesh. In order to
extend the availability period as well as increasing yield and quality by adopting
soil drench application of paclobutrazol in mango cv. BARI Aam-3 (Amrapali),
the present study was undertaken.
Materials and Methods
The experiment was conducted at the Germplasm Centre, Department of
Horticulture, Bangladesh Agricultural University, Mymensingh which is located
at 240 26/ latitude and 900 15/ longitude with an altitude of 8.3 m above the sea
level. Investigations related to bio-chemical analysis were carried out in the
Department of Biochemistry of Bangladesh Agricultural University,
Mymensingh. Ten years old BARI Aam-3 (Amrapali) plants with a plant spacing
of 5 x 5 m were included in the study. The factorial experiment was laid out in a
Randomized Complete Block Design with three replications. Paclobutrazol
(2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl) pentan-3-ol @
7500 and 10000 ppm and control (water application) and two times of application
(15 July and 15 October) were included in the study. By dissolving 30 and 40 ml
of 25 % paclobutrazol (Syngenta Chem. Co. Ltd., India) into one litre of fresh
water each, the solutions of 7500 and 10000 ppm were prepared, respectively.
Paclobutrazol solutions, each of 1 litre were soil drenched according to
Burondkar & Gunjate (1993), where 10 small holes (10–15 cm depth) were
prepared in the soil around the collar region of the plants just inside the fertilizer
ring. The prepared solutions of paclobutrazol as per treatment uniformly
drenched into the holes and the soil was reworked after application of
paclobutrazol. Only water (1 litre/plant) was applied in the control plants. The
data of the following parameters were recorded: length of terminal shoot, number
of leaves per terminal shoot, leaf area, length of panicle, number of secondary
branches per panicle, date of first panicle emergence, total number of panicles,
fruit set per panicle, number of fruits retained per panicle at 10 days interval
starting from pea stage to harvest, date of harvest, number of fruits per plant, fruit
weight, yield, edible portion, stone pulp ratio, peel pulp ratio, shelf-life, TSS,
titratable acidity, vitamin C, dry matter, reducing sugar, non reducing sugar and
total sugar content. The length and number of leaves of ten randomly selected
terminal shoots at flowering stage were measured and the average was worked
out. Leaf area was measured for all the 50 leaves taking 5 from each of ten above
selected shoots by a leaf area meter and expressed as square centimeter. The
length and number of secondary branches per panicle of 10 randomly tagged
panicles covering the whole tree was recorded and the average was worked out.
Ten panicles were randomly selected from each treatment. The initial number of

INFLUENCE OF PACLOBUTRAZOL ON GROWTH, YIELD 3
fruits of each panicle and the fruits retained per panicle at 10 day intervals
starting from pea stage up to harvest were recorded and the average was worked
out. After harvest, ten randomly selected fruits were allowed to ripen at room
temperature and fruit quality was determined using 10 fruits per tree. Total
Soluble Solid (TSS) of 10 fully ripened fruits for each treatment was estimated
by a hand refractometer and the average was worked out. The titratable acidity
(Ranganna, 1979), vitamin C (Plummer, 1971), reducing sugar (Miller, 1972)
and total sugar content (Jayaraman, 1981) in mango pulp were determined. Data
on different parameters of the experiment were tabulated and analyzed and the
treatment means were separated by Least Significant Difference (LSD) test at 5
% level of significance.
Results and Discussion
1. Combined effect on leaf, shoot and panicle characters of mango
Date of first panicle emergence in different treatment combinations of
paclobutrazol and time of application ranged from 09.12.06 to 01.01.07.
Paclobutrazol applied either @ 7500 ppm or 10000 ppm on 15 July exhibited
earlier panicle emergence compared to the delayed emergence in control.
Regardless of concentration, paclobutrazol had earlier panicle emergence.
Combined effect of paclobutrazol and time of application exhibited significant
effect on terminal shoot length, number of leaves per terminal shoot, leaf area,
panicle length, panicle breadth, number of secondary branches per panicle and
number of panicles per plant (Table 1). Control plants had the longest terminal
shoot (21.00 cm) treated on 15 October as against the shortest shoot (6.43 cm)
from the plants treated with paclobutrazol @ 10000 ppm on 15 July. Control
plants also exhibited maximum number of leaves (12.30) and leaf area (65.58
cm2) compared to minimum leaves per terminal shoot (9.10) and leaf area (44.51
cm2) in 10000 ppm paclobutrazol applied on 15 July. Paclobutrazol @ 7500 ppm
on 15 July application resulted in maximum panicle length (28.41 cm) and
panicle breadth (26.92 cm) and the control exhibited minimum panicle length
(22.63 cm) and breadth (20.92 cm). Maximum secondary branches per panicle
was obtained from the treatment combination of paclobutrazol @ 7500 ppm and
15 July application (36.30) followed by the combined effect of paclobutrazol @
7500 ppm and 15 October application (34.30), whereas the lowest value (26.25)
was recorded in control. Maximum number of panicles per plant was obtained
from the treatment combination of paclobutrazol @ 7500 ppm and 15 July
(412.00), while it was noticed minimum in control (232.33). Regardless of
application time and concentration, paclobutrazol suppressed vegetative growth
compared to control. Paclobutrazol can enhance the total phenolic content of
terminal buds that alter the phloem to xylem ratio of the stem, which is important
in restricting the vegetative growth and enhancing flowering by altering
assimilate partitioning and patterns of nutrient supply for new growth (Kurian

4 SARKER AND RAHIM
Table 1. Combined effect of paclobutrazol and time of application on leaf, shoot and panicle characters
Paclobutrazol
Concentration
Time of
application
Date of
first
appearance
of panicle
Length of
terminal
shoot (cm)
No. of
leaves per
terminal
shoot
Leaf area
(cm2)
Length of
panicle
(cm)
Breadth of
panicle
(cm)
Number of
secondary
branch /
panicle
Number of
panicles /
plant
Paclobutrazol at
7500 ppm
15 July
9.12.06
7.04
9.43
47.62
28.41
26.92
36.30
412.00
15 October
12.12.06
8.10
9.77
52.20
26.62
25.60
34.30
326.33
Paclobutrazol at
10000 ppm
15 July
9.12.06
6.43
9.10
44.51
24.33
24.62
32.27
400.33
15 October
12.12.06
7.15
9.30
49.79
23.25
24.20
29.80
296.67
Control (water
application)
15 July
01.01.07
19.30
11.83
65.58
22.63
20.92
26.25
232.33
15 October
01.01.07
21.00
12.30
65.16
22.90
21.67
26.78
242.66
CV (%)
-
7.68
6.88
5.49
5.06
3.50
7.11
6.20
LSD (0.05)
-
1.61
1.29
5.40
2.27
1.53
4.01
35.91

INFLUENCE OF PACLOBUTRAZOL ON GROWTH, YIELD 5
and Iyer, 1992). Soil drench applications of Cultar (Paclobutrazol) to mango cv.
Dashehari at Ludhiana prior to flower bud differentiation during the first week of
October affected the vegetative growth (Zora et al., 2000). The superior
performances in terms of higher panicle length, panicle breadth and number of
secondary branches per panicle in plants soil drenched with 7500 ppm
paclobutrazol on 15 July might be due to the optimum concentration and time of
application of paclobutrazol. It is also probable that the application of
paclobutrazol caused an early reduction of endogenous gibberellins levels within
the shoots as also observed by Anon. (1984), causing them to reach maturity
earlier than those of untreated trees. The total activity of auxin-like substances
increased the higher starch reserve, total carbohydrates and higher C: N ratio in
the shoots favoured flower bud initiation in mango. High level of auxins are
necessary for flower bud differentiation in mango and this manipulation by
sprays of synthetic substances at appropriate intervals may be helpful to induce
flowering (Jogdande and Choudhari, 2001). In mango, it was found that PP333
exhibited auxin like activity and influenced the auxin synthesis. Regular, profuse
and early bearing was also reported to be found due to paclobutrazol application
in mango cv. Banganapalli grown in India (Singh and Ranganath, 2006).
Paclobutrazol in general produced higher number of inflorescences per plant
compared to control. Burondkar et al. (1997) also noted profuse flowering in
paclobutrazol treated trees, when applied once during the month of July than
untreated ones. A significant positive correlation between shoot total non-
structural carbohydrates (TNC) and number of flowers developed was observed
by Phavaphutanon et al. (2000). Yeshitela et al. (2004) reported the increased
number of panicles for paclobutrazol treated plants is due to lower expenditure of
tree reserves to the vegetative growth parameters and consequently no assimilates
limitations, compared with an excessive vegetative growth in the control trees.
The application of paclobutrazol to soil antagonized gibberellin production in
new shoots and induced flowering and fruiting (Ram, 1999).
2. Combined effect on fruit set as well as fruit retention
Among the treatment combinations, paclobutrazol applying @ 7500 ppm on 15
July manifested maximum fruit set per panicle (17.73), followed by
paclobutrazol @ 7500 ppm on 15 October (16.60) and 10000 ppm and 15 July
application (16.40) (Table 2). The control plants exhibited minimum fruit set
(5.73). From 13 March 2007 to harvest, plants treated with paclobutrazol @ 7500
ppm on 15 July demonstrated maximum number of fruits per panicle and it was
recorded 2.00 at harvest, which was followed by the combined effect of 10000
ppm paclobutrazol and 15 July (1.70). The control plants always recorded the
least number of fruits per panicle and it was noted 0.60 at harvest. Trees
Paclobutrazol treated trees had higher food reserves enhanced the highest fruit set
compared to the lowest fruit set in the untreated tree with low reserves because of
excessive vegetative growth (Yeshitela et al., 2004) corroborate the present

6 SARKER AND RAHIM
result. Zora et al. (2000) revealed that cultar was the best treatment to promote
flowering as well as fruit set in mango cv. Dashehari at Ludhiana, when applied
in October.
Table 2. Combined effects of paclobutrazol and time of application on fruit set and fruit
retention per panicle
Paclobutrazol
Concentration
Time of
application
Fruit set per
panicle
Number of fruits retained per panicle at
13.03.07
23.03.07
02.04.07
12.04.07
Paclobutrazol at
7500 ppm (P1)
15 July
17.73
6.03
4.40
2.93
2.70
15 October
16.60
5.10
3.80
2.33
1.82
Paclobutrazol at
10000 ppm (P2)
15 July
16.40
4.80
3.70
2.83
2.30
15 October
13.65
4.00
3.05
2.10
1.30
Control (water
application) (P3)
15 July
5.73
2.79
2.80
1.93
1.25
15 October
6.63
1.80
2.83
2.03
1.27
CV (%)
5.57
8.86
11.16
11.04
5.80
LSD (0.05)
1.30
0.66
0.69
0.27
0.19
Table 2 contd.
Paclobutrazol
concentration
Time of
application
Number of fruits retained per panicle at
22.04.07
02.05.07
12.05.07
22.05.07
01.06.07
Harvest
Paclobutrazol at
7500 ppm (P1)
15 July
2.30
2.10
2.00
2.00
2.00
2.00
15 October
1.73
1.47
1.47
1.47
1.44
1.44
Paclobutrazol at
10000 ppm (P2)
15 July
2.10
2.00
1.80
1.77
1.73
1.70
15 October
1.23
1.03
1.00
1.00
1.00
1.00
Control (water
application) (P3)
15 July
1.17
0.77
0.70
0.67
0.67
0.60
15 October
1.20
0.80
0.70
0.67
0.67
0.67
CV (%)
9.39
9.81
7.84
8.70
7.39
7.78
LSD (0.05)
0.27
0.24
0.18
0.20
0.17
0.17
3. Combined effect on date of harvest, number of fruits, fruit characters,
yield and shelf life
Paclobutrazol in general exhibited earlier harvest than that of the control.
Induction of early flowering may also advance fruit maturity (Burondkar &
Gunjate 1993). Spraying of paclobutrazol in late August/early September in the
southwestern part of Hainan province, China promoted flowering and ripening
date (Xie et al., 1999). The advancement of harvesting time in case of
paclobutrazol application in mango cv. Banganapalli has been reported in India
(Singh and Ranganath, 2006). The combined effect of paclobutrazol and time of
application was found significant in respect of number of fruits per plant, fruit
weight, fruit length, fruit breadth, fruit thickness, stone pulp ratio, yield and
shelf-life but edible portion and peel pulp ratio did not exhibit significant
variation (Table 3 and Fig. 1). The number of fruits per plant was noticed to be
the highest (185.33) in the treatment combination of 7500 ppm paclobutrazol and
15 July application and the second highest number of fruits was manifested from

INFLUENCE OF PACLOBUTRAZOL ON GROWTH, YIELD 7
10000 ppm paclobutrazol when applied on 15 July (157.12), whereas the control
produced the lowest fruits (66.99). Paclobutrazol when soil drenched @ 7500
ppm on 15 July resulted in the highest fruit weight (303.67 g), which was
statistically identical to that of the combination of 7500 ppm and 15 October
application (293.33 g), as compared to the lowest fruit weight (177.00 g) in the
control. The paclobutrazol treated plants @ 7500 ppm on 15 July resulted in the
highest fruit length (11.10 cm) while the control plants had the least fruit length
(8.89 cm). The highest fruit breadth (7.41 cm) was recorded from the treatment
combination of 7500 ppm paclobutrazol and 15 July application as against
minimum value with 6.37 cm in control. Fruit thickness was recorded the highest
(6.84 cm) in the combination of paclobutrazol @ 7500 ppm and 15 July
application as against the lowest thickness (5.85 cm) in control. The plants soil
drenched with paclobutrazol @ 7500 ppm combined with 15 July or 15 October
application registered the lowest and same stone pulp ratio of 0.22 as compared
to the highest ratio (0.29) in control. The increased fruit weight in paclobutrazol
treated plants might be due to the increased rate of photosynthesis and an
increase in chlorophyll content. Quinlan (1981) opined that paclobutrazol
increased the water use efficiency in photosynthesis of leaves by increasing the
rate of photosynthesis for a given level of leaf stomatal conductance or
transpiration. Paclobutrazol in general caused an increase in fruit number as well
as yield per plant compared to control. A significantly higher fruit set and fruit
retention in the paclobutrazol treated plants had a favourable impact on
culminating higher final fruit number and yield per plant. Paclobutrazol has been
reported to exert influence on partitioning the photosynthates to the sites of
flowering and fruit production consequent to the reduction of vegetative growth.
In this context, Kurian et al. (2001) reported that paclobutrazol appeared to
favourably alter the source sink relationship of mango to support fruit growth
with a reduction in vegetative growth.
Table 3. Combined effect of paclobutrazol and time of application on number of
fruits and fruit characters
Paclobutrazol
concentration
Time of
application
Date of
harvest
Number of
fruits per
plant
Fruit
Weight
(g)
Length
(cm)
Breadth
(cm)
Thickness
(cm)
Paclobutrazol at
7500 ppm (P1)
15 July
04.06.06
185.33
303.67
11.10
7.41
6.84
15 October
04.06.06
140.78
293.33
10.99
7.29
6.68
Paclobutrazol at
10000 ppm (P2)
15 July
04.06.06
157.12
260.67
10.22
7.17
6.39
15 October
04.06.06
93.50
239.47
9.84
6.93
6.30
Control (water
application) (P3)
15 July
26.06.06
66.99
177.00
8.89
6.37
5.85
15 October
26.06.06
68.25
178.33
8.95
6.38
5.88
CV (%)
-
4.29
3.69
5.04
4.51
5.02
LSD (0.05)
-
9.26
16.25
0.92
0.57
0.58

8 SARKER AND RAHIM
Table 3 contd.
Paclobutrazol
Concentration
Time of
application
Edible
portion (%)
Stone pulp
ratio
Peel pulp
ratio
Shelf life
(days)
Paclobutrazol at
7500 ppm (P1)
15 July
69.55
0.22
0.23
9.67
15 October
68.76
0.22
0.24
9.17
Paclobutrazol at
10000 ppm (P2)
15 July
68.09
0.23
0.23
9.50
15 October
66.80
0.25
0.24
9.33
Control (water
application) (P3)
15 July
65.82
0.28
0.23
7.67
15 October
65.95
0.29
0.23
8.00
CV (%)
3.67
8.81
5.59
5.95
LSD (0.05)
-
0.04
-
3.23
P1 : Paclobutrazol @ 7500 ppm D1 : 15 July application
P2 : Paclobutrazol @ 10000 ppm D2 : 15 October application
P3 : Control (water application)
The treatment combination of 7500 ppm paclobutrazol and 15 July application
exhibited maximum fruit yield (55.05 kg/plant). The next higher but statistically
identical yield (39.77 and 39.40 kg/plant) were noticed from the treatment
Figure 1. Effect of paclobutrazol and time of application on the yield per plant of mango
Vertical bar represents LSD at 5% level
0
1
20
30
40
50
60
P1D
P1D2
P2D
P2D2
P3D1
P3D
Paclobutrazol concentration and its time of application
Yield (kg/plant)
(kg/plant)

INFLUENCE OF PACLOBUTRAZOL ON GROWTH, YIELD 9
combinations of 7500 ppm and 15 October and 10000 ppm and 15 July,
respectively. The control plants showed minimum (11.72 kg/plant) yield.
Paclobutrazol @ 7500 ppm combined with 15 July application exhibited the
highest shelf life (9.67 days) as compared to the lowest value with 7.67 days in
control. Moreover, the effect of paclobutrazol on increasing the chlorophyll
content of leaves, besides influencing the CO2 assimilation might manifest higher
photosynthetic efficiency leading to higher accumulation of carbohydrates, that
might have influence on higher fruit bud initiation, flowering, fruit set and yield
(Richardson and Quinlan, 1986). Plants treated with paclobutrazol in mango cv.
Langra in India produced the highest number of fruits and yield (Karuna et al.,
2005; Karuna et al., 2007).
4. Combined effect on fruit quality
There were profound variations in respect of TSS, titratable acidity, vitamin C,
dry matter content; reducing, non reducing and total sugar due to the combined
effect of paclobutrazol and time of application, while pH and moisture content
did not exhibit significant differences (Table 4). Plants soil drenched with
paclobutrazol @ 7500 ppm on 15 July recorded the highest TSS content
(28.00%) compared to the lowest TSS in control (22.27%). The lowest value of
the titratable acidity with 0.19 was exhibited when paclobutrazol @ 10000 ppm
was applied to the plants on 15 July, whereas the highest value (0.24) appeared in
the control. Paclobutrazol when applied @ 7500 ppm on 15 July resulted in
maximum vitamin C content (35.02 mg/100g pulp), while control plants had
minimum vitamin C content (28.73 mg/100g pulp).
Table 4. Combined effect of paclobutrazol and time of application on quality
attributes
Paclobutrazol
Concentration
Time of
application
TSS
(%)
pH
Titratable
acidity (%)
Vitamin C
(mg/100 g pulp)
Paclobutrazol at
7500 ppm
15 July
28.00
6.13
0.20
35.02
15 October
26.53
6.30
0.22
34.73
Paclobutrazol at
10000 ppm
15 July
25.13
6.02
0.19
33.72
15 October
24.57
6.09
0.20
32.96
Control (water
application)
15 July
22.27
5.55
0.23
28.73
15 October
22.47
5.79
0.24
28.90
CV (%)
6.56
4.73
5.87
3.82
LSD (0.05)
2.96
-
0.03
2.25

10 SARKER AND RAHIM
Table 4 contd.
Paclobutrazol
concentration
Time of
application
Moisture
content
(%)
Dry matter
content
(%)
Reducing
sugar
(%)
Non
reducing
sugar (%)
Total
sugar
(%)
Paclobutrazol at
7500 ppm
15 July
78.01
21.99
5.42
13.95
19.37
15 October
79.78
20.22
5.35
13.87
19.22
Paclobutrazol at
10000 ppm
15 July
81.15
18.85
5.21
13.50
18.71
15 October
81.93
18.07
5.15
13.44
18.59
Control (water
application)
15 July
83.61
17.39
4.81
12.48
17.30
15 October
81.56
17.44
4.76
12.43
17.19
CV (%)
2.61
4.67
3.00
2.93
2.91
LSD (0.05)
-
1.61
0.28
0.71
0.97
Paclobutrazol applied at 7500 ppm on 15 July exhibited maximum dry matter
(21.99%) compared to the lowest value with 17.39% in control. Reducing sugar
content was recorded the highest (5.42%) in the plants treated with paclobutrazol
@ 7500 ppm on 15 July as against the lowest content (4.76%) in control.
Paclobutrazol irrespective of concentration and time of application produced
higher reducing sugar content compared to control. Fruits from the plants treated
with paclobutrazol @ 7500 ppm on 15 July contained maximum non reducing
sugar (13.95%), whereas control plants showed minimum sugar (12.43%). Soil
drenched with paclobutrazol @ 7500 ppm on 15 July resulted in maximum total
sugar content of 19.37% as against minimum sugar (17.19%) in control. All the
treatment combinations except control were statistically identical and
demonstrated higher total sugar. Improvement in fruit quality in respect of TSS,
TSS to acid ratio, total sugar and reducing sugar in response to paclobutrazol can
be related to assimilate partitioning of the plant. Due to higher suppression of
vegetative growth, assimilates need to become unidirectional towards developing
fruit, as a result paclobutrazol treated trees exhibited higher fruit quality
attributes. With the same justification, the control trees had lower TSS and sugars
but higher titratable acidity. Paclobutrazol improved fruit quality (Vijayalakshmi
& Sirivasan, 1998; Hoda et al., 2001 and Yeshitela et al., 2004). Vijayalakshmi
and Srinivasan (2000) reported that paclobutrazol in Alphonso mangoes in India
had the greatest effect enhancing all the qualitative parameters (ascorbic acid,
total sugar, reducing sugar and TSS, except for acidity) in harvested fruits. Soil
treatment with paclobutrazol improved the fruit quality attributes (Singh and
Singh, 2006).
Conclusion
The result revealed that soil drenched with paclobutrazol either at 7500 ppm or
10000 ppm on 15 July advanced panicle emergence as well as harvest in mango
cv. BARI Aam-3 (Amrapali) by 23 and 22 days, respectively, which will in turn

INFLUENCE OF PACLOBUTRAZOL ON GROWTH, YIELD 11
help the growers in extending the availability period of mango. Paclobutrazol @
7500 ppm on 15 July exhibited superior results pertaining to fruit yield and
quality.
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