Effect of nutrients and plant growth regulators on fruit retention, yield and physico-
chemical characteristics in aonla cv. NA-10

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

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

E-mail : profsnghosh@yahoo.co.in

ABSTRACT

To check  pre-mature fruit drop in aonla cv. NA-10, an investigation was undertaken during 2007 and 2008 in a
Seven year old private orchard at Jhargram, Paschim Midnapore, West Bengal, where the soil is red laterite and pH
ranges between 4.5 and 5.5. Treatments included foliar spray of urea (0.2%) + DAP (0.2%), ZnSO

4
 (0.5%), Borax

(0.4%), NAA (10 and 20 ppm), Vermiwash (3 ml/l), Humaur (2 ml/l) and water spray (control). Results of two years of
investigation revealed that spray of NAA at 10 ppm was the best to increase fruit retention, followed by NAA 20 ppm,
Vermiwash and Borax, which consequently resulted in the highest fruit yield of 54.9, 52.0, 46.8 and 36.2 kg/plant,
respectively, against 13.8 kg in the control. Fruit weight was maximum with 0.5% ZnSO

4
 spray, followed by NAA 10

ppm. Fruit quality with regard to TSS, total sugar and ascorbic acid content was better in all the treated fruits
compared to control.

Key words: Aonla, fruit quality, laterite soil, growth regulators, nutrients, yield

Short communication

J. Hortl. Sci.
Vol. 4 (2): 164-166, 2009

1MPS Farm, Dahijuri, Jhargram, Paschim Midnapore

Aonla (Emblica officinalis Gaertn.), is being grown
in diverse soil and climate for its high nutritive and therapeutic
value. In West Bengal, the demand for aonla fruits has been
progressively increased due to its popularity for preparation
of chip bits and morabba. Its cultivation has been gradually
expanded and red laterite zone of the state is now being utilized
for the purpose. In red and laterite soils of West Bengal, the
plant starts bearing at the age of 2nd year and  reaches its  full
bearing  capacity at the  age of 8th year. One  of the major
constraints of aonla cultivation in this zone is occurrence of
heavy fruit drop. Although, fruit drop in aonla is a common
phenomenon (Allemullah and Ram, 1990), the fruit drop in
laterite soil is severe and it continued till harvest resulting low
yield of mature fruits. To check the pre-mature fruit drop in
aonla and to improve the yield and fruit quality, an investigation
was carried out with the application of major and minor
nutrients and plant growth regulators.

The experiment was carried out on seven year old
budded plants of aonla cv. NA-10 planted at a spacing of 5
m x 5 m during 2007 and 2008 in a private farm which is
situated near the Regional Research Station of Bidhan Chandra
Krishi Viswavidyalaya, Jhargram, Paschim Midnapore, West
Bengal. The soil of the experimental orchard was laterite

having surface soil pH 5.5. There were eight treatments viz.,
T

1
- Urea 0.2% + DAP (Di-ammonium phosphate) – 0.2%,

T
2
-ZnSO

4
 – 0.5%, T

3
-Borax – 0.4%, T

4
-NAA-10 ppm, T

5
-

NAA-20 ppm, T
6
- Vermiwash – 3 ml/l, T

7
-Humaur 2 ml/l

and T
8
-water spray (control). The Humaur is a bio-organic

foliar nutrient, manufactured by Hindustan Antibiotics Ltd.,
Pimpri, Pune and reported to have enzymes, vitamins and
organic acid precursor. The plants were sprayed with the
chemicals after sunset three times i.e., on 25th May, 5th July
and 5th August of 2007 and 2008. The experiment was laid
out in a Randomized Block Dsign with four replications. The
plants were fertilized with 40 kg FYM, 200g N, 100g P

2
O

5

and 100g K
2
O/plant/year. Observations were recorded on

per cent fruit retention, yield and physico-chemical composition
of fruits. The acidity, total sugar and ascorbic acid content
were estimated as per the methods suggested by A.O.A.C.
(1990). For recording fruit retention, 4 shoots /plant in four
directions were tagged and counted when the fruits were
pea size and final counting was made at maturity and thereby
percentage of retention was calculated.

It is evident from the data presented in Table 1 that
fruit drop in aonla is severe in laterite soil and gave only



165

2.5% retention as observed from the control plants. It was
also observed that fruit drop in aonla was mainly associated
with the hormonal imbalances as NAA 10 ppm sprayed gave
maximum fruit retention of 22.3% followed by NAA 20 ppm,
which resulted in second best fruit retention (17.1%). Singh
et al (2007) also observed reduce fruit drop in aonla with
NAA 10 ppm at Faizabad (U.P). Beneficial effect of NAA
application in reducing fruit drop may be explained from the
fact that it maintains the on-going physiological and bio-
chemical process of inhibition of abscission (Tomaszewska
and Tomaszewska, 1970). Besides, hormone and
micronutrient were observed to be one of the controlling
factors for improving fruit retention in aonla. Among the
two micronutrients, boron gave the better result in aonla
than zinc in controlling fruit drop. It is well known that boron
play a significant role in carbohydrate transport and various
physiological processes like nitrogen metabolism, active salt
absorption, hormone metabolism, fat metabolism, etc. within
the plant (Nason and McElroy, 1963). It was further observed
that vermiwash application, a bye-product of vermi-compost,
showed a beneficial effect on fruit retention (13.4%) in aonla.
Beneficial effect of vermiwash in fruit retention may be
explained as it contain most of the macro and micronutrients,
hormones, enzymes etc. in minute quantity which may
helped to activate and regulate many physiological processes
within the plant. It was interestingly noted that nitrogen and
phosphorus application in the form of urea and di-ammonium
phosphate had no positive role in fruit retention, although
beneficial effect of urea spray on fruit retention and yield
was observed in many fruit crops like Mango (Sharma et
al. 1977), Guava (Arora and Singh, 1970), Cashew (Ghosh
and Chatterjee, 1990), etc.

Fruit yield in aonla was directly co-related with the
fruit retention under different treatments (Table 1). The
highest yield of 54.9 kg/plant was recorded from the plant
treated with NAA - 10 ppm followed by NAA 20 ppm (52.0
kg/plant) and they were statistically at par among themselves
in fruit production. The highest fruit yield in NAA treated
plants was due to highest fruit retention as compared to
other treatments. Vermiwash application gave the 2nd highest
yield in aonla (46.8 kg/plant) after NAA (10 and 20 ppm).
Micronutrients (Zn and boron) and Humaur application also
showed better result in yield improvement in aonla as
compared to control. No response of urea and DAP
application was observed with regard to their effect on yield
enhancement as compared to control. From this investigation,
it is clearly understood that application of micronutrients
and hormones like NAA are needed in addition to
macronutrients during fruit setting and development process
for obtaining a good harvest of aonla in laterite soil.

Fruit weight was significantly the highest (31.3 g)
in the plants sprayed with ZnSO

4
 at 0.5% followed by NAA

10 ppm (29.4 g) and 20 ppm (28.4 g). Beneficial effect of
zinc in improving fruit weight was also observed by
Langthasa and Bhattacharyya (1993) in Assam lemon, Wali
and Sharma (1997) in Kinnow mandarin and Ghosh and
Besra (2000) in Sweet orange. It was noted that all the
treatments i.e., macro and micronutrients and plant growth
regulators sprayed helped to increase fruit weight
significantly as compared to control. Fruit length and breadth
were also improved due to different treatments but they
were not statistically significant. Similarly pulp content was
also slightly improved due to different nutrients and plant
growth regulator application and was maximum under 0.5%

Table 1. Effect of nutrients and plant growth regulators on fruit retention, yield and fruit quality in aonla cv. NA 10 (average of two
years)

Treatment Fruit Yield/ Fruit Fruit Fruit Pulp TSS Acidity Total Vit. C
retention plant weight length breadth (%)  (0B)  (%) sugar (mg/100g)

(%)  (kg) (g) (cm) (cm)  (%)

Urea – 0.2% +
DAP-0.2% 2.8 (9.63) 14.2 21.3 4.0 4.3 93.2 8.7 1.1 4.9 545
ZnSO

4
 – 0.5% 6.1 (14.30) 29.4 31.3 4.6 4.8 95.2 8.4 1.1 4.9 540

Borax – 0.4% 8.6 (17.05) 36.2 25.6 4.4 4.5 92.0 8.6 1.1 4.7 518
NAA – 10 ppm 22.3 (28.18) 54.9 29.4 4.5 4.7 93.7 9.5 1.5 5.1 528
NAA – 20 ppm 17.1 (24.43) 52.0 28.4 4.5 4.6 92.7 9.3 1.2 5.2 566
Vermiwash – 3ml/l 13.4 (21.47) 46.8 27.6 4.4 4.7 92.6 9.0 1.2 4.9 535
Humaur – 2 ml/l 4.9 (12.79) 23.5 22.9 3.9 4.5 93.0 9.0 1.0 5.1 563
Control (Water spray) 2.5 (9.10) 13.8 20.0 3.8 4.3 92.1 8.2 1.0 4.6 488
CD(P=0.05) 2.1 4.2 1.2 NS NS NS 0.4 NS 0.2 6.5

Figures in parentheses are angular transformed value

J. Hortl. Sci.
Vol. 4 (2): 164-166, 2009

Nutrients and plant growth regulators spray in yield of aonla



166

zinc sulphate spray (95.2%) but the treatments were not
statistically significant.

Total soluble solids and total sugar content were
significantly more in the fruits treated with NAA 10 ppm,
NAA 20 ppm, vermiwash and humaur, which resulted 9.0
to 9.50B in T.S.S. and 4.9 to 5.2% total sugars as compared
to 8.20B and 4.6% of TSS and total sugars, respectively in
control. Fruit acidity was not significantly improved due to
different treatments. However, ascorbic acid content was
significantly better in all the treated plants as compared to
control. The ascorbic acid content in fruit was estimated as
the highest in fruits in treatment with NAA 20 ppm (566
mg/100 g), which was closely followed by Humaur (563
mg/100 g) and lowest in control (488 mg/100 g). Singh et al
(2007) also observed higher ascorbic acid content in aonla
fruits treated with micronutrients (0.5% ZnSO

4
 and 0.4%

CuSO
4
) and plant growth regulators (10 ppm NAA and 25

ppm GA
3
).

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A.O.A.C. 1990. Official Methods of Analysis. Association
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(MS Received 29 December 2008, Revised 22 September 2009)

Ghosh et al

J. Hortl. Sci.
Vol. 4 (2): 164-166, 2009