Short communication

J. Hortl. Sci.
Vol. 4 (2): 158-160, 2009

Pomegranate (Punica granatum L.), belonging to
the family Punicaceae, is one of the favourite table fruits in
the world, for its refreshing juice with nutritional and
medicinal properties. This fruit crop has wide adaptability
and it grows in tropical, sub-tropical and even temperate
regions. In India, pomegranate is commercially cultivated
in Maharashtra and parts of Karnataka where good quality
fruits are produced due to dry and hot climate. The crop is
also being cultivated in other states. In West Bengal, the
crop has been introduced in the red laterite zone of the state
for its dry and hot climatic condition. Among seven cultivars
studies, Ruby was found to be the best in all aspects (Tarai
and Ghosh, 2006). One of the main problems under Jhargram
(West Bengal) condition is that cv. Ruby exhibits heavy
flowering and fruit drop by increasing the fruit set and fruit
retention. Plant growth regulators are reported to play a
significant role in pomegranate (Chaudhari and Desai, 1993).
Hence, an attempt has been made to find suitable growth
regulators and their doses for improving fruit set and yield
in pomegranate cv. Ruby, under West Bengal conditions.
The experiment was conducted in a private orchard at
Jhargram, Paschim Midnapore, West Bengal during 2006-
07 and 2007-08 on 6-year old Ruby planted at a spacing of
3 x 3 m. The soil of the experimental orchard was laterite
and acidic (pH 5.8) within 2 feet depth. The plants were

Effect of plant growth regulators in yield and fruit quality
in pomegranate cv. Ruby

S.N. Ghosh, B. Bera1, S. Roy1 and A. Kundu1
Department of Fruits and Orchard Management

Faculty of Horticulture
Bidhan Chandra Krishi Viswavidyalaya, Mohanpur – 741252, India

E-mail: profsnghosh@yahoo.co.in

ABSTRACT

An investigation was carried out during 2006-07 and 2007-08 to harness  beneficial effects of plant growth regulators
on yield and fruit quality in pomegranate cv. Ruby. Seven treatments with three growth regulators, viz., NAA at 25, 50
ppm; GA

3
 at 10, 20 ppm; 2,4-D at 5, 10 ppm and control (water spray) were sprayed three times starting  at 50%

flowering stage and, subsequently, at 21 days’ interval. Results revealed that application of NAA at 25 ppm gave
significantly high fruit set (44.3%) and fruit retention (44.1%) which resulted in highest fruit yield of 7.8 kg/plant
at the age of 7 years, as against 1.7 kg in the control. Fruit weight and quality improved significantly due to growth
regulator sprays.

Key words: Pomegranate, growth regulators, yield, fruit quality

fertilized every year with 20 kg FYM, 300 g N, 100 g P
2
O

5

and 200 g K
2
O/plant in two splits i.e., in December and

February, followed by watering at regular intervals. Six
prophylactic sprays were given to control insect pests and
diseases. Four shoots per plant were tagged in four directions
for recording observations on fruit set and retention. The
experiment was laid out in Randomized Block Design with
four replications, and two plants per replication. There were
seven treatments with three growth regulators, viz., NAA
at 25, 50 ppm; GA

3
 at 10, 20 ppm; 2,4-D at 5, 10 ppm and

control (water spray). These chemicals were thoroughly
sprayed after sunset, thrice, along with the control (water
spray) using teepol as surfactant. The first spray was given
at 50% flowering stage i.e., on 20th January of 2007 and
2008 and subsequent sprays were 21-day intervals from
the 1st spray. Fruit yield was calculated on the basis of actual
weight of mature fruits harvested from each plant up to
onset of rainy season i.e., 10th June. For fruit weight 5 fruits
per plant were taken and average weight was calculated.
The T.S.S. was measured by hand refractometer while
acidity was determined by following the standard method
(A.O.A.C., 1990).

Results of two years of investigation (Table 1)
revealed that application of NAA had beneficial effect on
fruit retention and lower concentration i.e., 25 ppm was the

1MPS Farm, Dahijuri, Paschim Midnapore, West Bengal



159

most effective which resulted maximum fruit setting (44.3%)
and retention of fruits (44.1%) while, in control, these were
lowest (20.2% and 24.2%, respectively). Beneficial role of NAA
in reducing fruit drop may be explained from the fact that it
maintain on-going physiological and biochemical process of
inhibition of abscission (Tomaszewska and Tomaszewska,
1970). It was noted that 2,4-D at 10 ppm was the second best
plant growth regulator for improving fruit set and retention.

Fruit yield was highest in both the years of
investigation with foliar application of NAA (25 ppm)
increase in yield was more than double compared to the
control plants. Highest yield increment with 25 ppm NAA
application was due to maximum fruit retention. The result
was in close conformity with findings of Venkatesan and
Kader Mohideen (1994) in pomegranate, who also obtained
highest fruit yield with 2,4-D at 20 ppm, closely followed by
NAA at 25 ppm. It was observed that effect of NAA in
yield improvement drastically reduced from 25 ppm and
similar observation was also reported by Venkatesan and
Kader Mohideen (1994). Application of 2,4-D at 10 ppm
was found to be the second best treatment in improving
fruit yield but GA at any level showed less effectiveness in
yield increment. However, Pawar et al (2005) recorded
highest yield in cv. Mridula of pomegranate in Maharashtra
with 75 ppm GA

3
, while, Mohamed (2004) from Assiut

(Egypt) recommended 150 ppm of GA
3
 for getting heaviest

fruit with lowest fruit-splitting in cv. Manfalouty of
pomegranate. These reports clearly indicate that the growth
regulator and its concentration need to be standardized for
a given locality to harness beneficial effects of that hormone.

Fruit weight significantly improved with the
application of growth regulators excepting NAA @ 50 ppm
and, the treatments were statistically at par in improving
fruit weight (Table 1). Beneficial role of NAA, GA

3
 and

2,4-D in improving fruit weight was also reported by Ghosh
et al (1995) in sweet orange, Hasan and Chattopadhyay
(1996),  in litchi Pandey (1999) in ber and Pawar et al (2005)
in pomegranate. Positive role of auxins like NAA, 2,4-D
and gibberellins like GA

3
 application on fruit weight may be

explained from the fact that these are associated with cell
division and cell enlargement (Leopold, 1958; Weaver, 1972).

Fruit size (length and breadth) and juice recovery
parameters were not affected by growth regulator treatment.
Total soluble solids (TSS) content in the fruit significantly
increased with growth regulator application and highest TSS
content was measured in plants sprayed with NAA 25 ppm
and 2,4-D 10 ppm (14.80B), but, was statistically at par with
other treatments. In control plants the TSS content was
12.50B. Beneficial effect of plant growth regulators in
improving TSS content in pomegranate was also observed
by Mohamed (2004). Fruit acidity was significantly different
among treatments and it was highest (0.63%) in GA 10 ppm
and lowest (0.39%) in NAA 25 ppm treatments. TSS:acid
ratio, which determines organoleptic test of fruits, was
highest with NAA ppm (37.9) and lowest in control (28.4).
Improvement in TSS of fruits due to auxins (NAA, 2,4-D)
and GA spray may be explained from the fact that application
of these growth regulators after fruit set probably improved
the physiology of leaves, thereby causing better translocation
of vital components in the fruit and assimilation/utilization
of photosynthates by the developing fruit (Pandey, 1999).

REFERENCES

A.O.A.C. 1990. Official Methods of Analyais. Association
of Official Agriculture Chemists (15 th Edn.),
Washington, D.C.

Chaudhari, S.M. and Desai, U.T. 1993. Effect of plant
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Table 1. Effect of plant growth regulators on yield and fruit quality in pomegranate cv. Ruby (Mean of 2 years)

Treatment Fruit set Fruit retention Yield/plant (kg) Fruit Fruit Fruit Juice TSS Acidity TSS/acid
(%) (%) weight length breadth  (%) (0B)  (%)  ratio

2007 2008 Mean  (g)  (cm)  (cm)

NAA 25 ppm 44.3 (41.73) 44.1 (41.61) 6.2 9.4 7.8 158 6.8 7.3 71.3 14.8 0.39 37.9
NAA 50 ppm 24.1 (29.40) 36.7 (37.29) 2.0 2.6 2.3 124 6.4 6.6 70.4 14.0 0.49 28.6
GA 10 ppm 25.9 (30.59) 25.8 (30.53) 6.9 2.6 4.8 163 7.0 7.3 70.7 13.8 0.63 21.9
GA 20 ppm 20.8 (27.13) 25.0 (30.00) 5.1 1.8 3.5 161 6.9 7.2 67.9 14.0 0.42 33.3
2, 4-D 5 ppm 34.1 (35.73) 27.5 (31.63) 4.4 6.7 5.6 157 7.0 7.1 78.2 14.6 0.40 36.5
2, 4-D 10 ppm 40.5 (39.52) 29.2 (32.71) 5.9 7.5 6.7 159 6.9 7.0 77.5 14.8 0.41 36.1
Control
(water spray) 20.2 (26.71) 24.2 (29.47) 2.5 0.9 1.7 128 6.3 6.8 70.0 12.5 0.44 28.4
CD(P=0.05) 4.5 2.5 0.5 0.2 0.4 5.2 NS NS NS 0.4 0.02 -

Figures in parentheses are angular transformed values

J. Hortl. Sci.
Vol. 4 (2): 158-160, 2009

Plant growth regulators in yield and quality of pomegranate



160

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Ghosh et al

J. Hortl. Sci.
Vol. 4 (2): 158-160, 2009