INTRODUCTION
Banana is the major fruit crop of Kerala cultivated

by marginal and poor farmers. It grows well under a wide
range of agro-climatic situations and cropping systems. It
can be well fitted in crop rotations, multiple cropping,
intercropping and companion cropping (Varkey and
Pushkaran, 1992). Among the different cultivars of banana,
“Njalipoovan” (Musa AB group) is one of the popular
varieties cultivated in the homesteads of Kerala.This variety
assumes significance in view of its high export potential
mainly due to its edible and keeping quality. Banana is a
soil exhaustive crop which requires adequate quantity of
nutrients throughout its growth period. A judicious
application of fertilizers not only gives high yield but also
improves the quality of the produce. Under Onattukara
conditions, the nutrient requirement of any of cultivars of
banana especially “Njalipoovan” has not been standardized.
The present investigation was therefore, taken up to study
the effect of different levels of nitrogen, phosphorus and
potassium on the growth, yield and quality and to formulate
an economic nutrient management schedule for banana cv.
“Njalipoovan” in Onattukara soil.

Standardization of NPK requirement in banana cv. “Njalipoovan” (Musa AB group) in
Onattukara soil of South Kerala

M. Indira and C. S. Nair1
Onattukara Regional Agricultural Research Station

Kayamkulam-690 502, India
E-mail: indirasuresh@gmail.com

ABSTRACT

Banana cv. “Njalipoovan” (Musa AB group, Syn. Ney Poovan) is one of the popular varieties cultivated in the
homesteads of Kerala. This variety has high export potential due to its edible and keeping quality. Eventhough
fertilizer requirement was worked out for different varieties; no attempt has been made to standardize the
nutrient requirement of banana cv. “Njalippovan”, especially in the loamy sand soils of Onattukara. Field
experiments were conducted for two years (1998-2000) at Onattukara Regional Agricultural Research Station,
Kayamkulam to study the influence of three levels each of N (100, 200 and 300 g plant-1), P

2
O

5 
(100, 200 and 300

g plant-1) and K
2
O (200,400 and 600 g plant-1) with one absolute control (n

o
p

o
k

o
) on growth, yield, quality and

economics of cultivation. Increasing the rate of application of nitrogen, phosphorus and potassium improved
the growth and yield. Total soluble solids (TSS), total sugars and reducing sugars increased with increasing
levels of nitrogen and potassium. Fruit acidity decreased at higher rate of N and K

2
O. Applied phosphorus had

no effect on quality of fruits. Application of N, P
2
O

5 
and K

2
O at 200:200:400 g plant-1 proved to be ideal for

maintaining higher yield and benefit: cost ratio.

Key words: Njalipoovan, growth, yield, quality, economic returns

MATERIAL AND METHODS
The field experiment was conducted in the garden

land of the farm attached to Onattukara Regional
Agricultural Research Station, Kayamkulam for two seasons
(1998-99 and 1999-2000). The experimental site had soils
of the class isohyperthermic ustic quartzi psamments, with
pH of 5.27 and low content of organic carbon (0.27%),
available N (184.58 kg ha-1), available P

2
O

5 
(9.70 kg ha-1)

and exchangeable K
2
O (77.02 kg ha-1). The experiment was

laid out in confounded 33 factorial RBD. Three levels each
of N (100, 200 and 300g plant -1), P

2
O

5
 (100,200 and 300g

plant -1) and K
2
O (200,400 and 600g plant -1) with one

absolute control (n
0
p

0
k

0
) constituted the treatments. Urea

(46% N), Mussoorie rock phosphate (20% P
2
O

5
) and

Muriate of potash (60% K
2
O) were used as the source of

N, P and K, respectively.

Banana suckers were planted at a spacing of
2.13 mx 2.13 m in plots of size 10.70m x 8.50m (20 plants
plot-1) during the month of May 1998 and 1999. Fertilizers
at the calculated amount were applied in two equal splits at
two and four months after planting to supply different levels

1Present address: Retired Dean, College of Agriculture, Vellayani, Thiruvananthapuram

J. Hortl. Sci.
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128

of nitrogen, phosphorus and potassium as per the treatments.
General crop recommendations for banana varieties other
than “Nendran” were followed (KAU, 1996).

Four plants in each plot were marked as
observational plants and growth characters such as height
and girth of pseudostem, number of functional leaves and
leaf area index (LAI) were recorded six months after
planting. Leaf area was computed using the formula lx bx
0.8 (Murray, 1960) where ‘l’ is the length of the lamina and
‘b’ the breadth of the lamina. Leaf area index was
determined using the formula, leaf area per plant (cm2)/land
area occupied by the plant (cm2) (Watson, 1947). Yield and
yield attributes viz., number of hands bunch-1 and number
of fingers bunch-1 were recorded at harvest. Quality analysis
of the fully ripe fruits such as total soluble solids (TSS),
total sugars, reducing sugars, acidity and shelf life were
done following standard procedures (AOAC, 1977 and
Ranganna, 1977).  The data were statistically analysed by
applying the techniques of analysis of variance for
confounded RBD (Panse and Sukhatme, 1967). Total cost
of cultivation and gross returns were calculated from
average input cost and average market price of the produce
during the period of investigation and benefit: cost ratio
was computed as follows: Benefit: cost ratio (BCR) = Gross
income / Cost of cultivation

RESULTS AND DISCUSSION

Growth attributes

Application of N at the highest level (300 g plant -1)
significantly increased the height and girth of pseudostem,
number of functional leaves and LAI in both the years (Table
1).  Stimulation of vegetative growth at higher rates of applied
N has been reported earlier in banana cv. Palayankodan

(Sheela, 1982) and in “Nendran” (Geetha and Nair, 2000).
Large leaf size combined with more number of functional
leaves retained per plant at higher levels of N resulted in
higher LAI. It is a proven fact that adequate supply of nitrogen
promotes vegetative growth and helps to retain leaves for a
longer time (Tisdale et al, 1995).

The influence of different levels of phosphorus in
increasing the plant height is indicative of the role of
phosphorus in improving the vegetative growth. The height
and girth of pseudostem was maximum with the highest
level of K (600 g plant-1). The influence of medium rate of
K (400 g plant -1) in increasing the number of functional
leaves and retaining up to harvest indicates the significant
role of K in promoting vigorous healthy crop growth.
Potassium at higher rates significantly influenced the LAI.
The higher number of functional leaves and greater leaf
size might have contributed to the higher LAI at higher
levels of K supply.

Crop duration

Application of nitrogen at 300 g plant-1 markedly
reduced the total duration of the crop in both the years (Table
2). Applied nitrogen exerted its effect on total crop duration
mainly by influencing the days to shooting. There was a
reduction of 22-29 days in the total crop duration when
nitrogen level was increased from 100 to 300 g plant-1.
Nitrogen reduced phyllochron and increased the leaf area
in a short span of time thereby helping the plant to attain
early physiological maturity. Thus shooting occured early
which in turn reduced the total crop duration (Geetha, 1998).

Potassium applied at 400 g plant-1 profoundly
reduced duration of the crop. This might be due to the
enhanced vigour of the plant and increased vegetative

Table 1. Effect of nitrogen, phosphorus and potassium on growth attributes

 Main effects Pseudostemheight (cm) Pseudostemgirth (cm) No. of functional leaves LAI

1998-99 1999-2000 1998-99 1999-2000 1998-99 1999-2000 1998-99 1999-2000

N
 1

119.67 117.39 31.89 31.00 8.61 6.50 0.74 0.68
N

2
139.50 142.17 44.44 41.33 10.94 9.61 1.23 1.13

N
3

174.94 166.44 47.83 44.94 11.83 10.78 1.77 1.61
CD (P=0.05) 1.677 2.437 1.535 1.285 0.57 0.65 0.043 0.065
P

1
142.00 139.00 39.44 37.39 10.22 8.33 1.11 1.03

P
2

144.83 141.78 41.72 39.50 10.22 9.06 1.28 1.15
P

3
145.28 145.22 43.00 40.39 10.94 9.50 1.35 1.24

CD (P=0.05) 1.677 2.437 1.535 1.285 0.57 0.65 0.043 0.065
K

1
135.78 133.83 36.44 33.89 9.61 8.06 1.00 0.98

K
2

147.67 143.83 42.56 40.94 10.39 9.22 1.33 1.18
K

3
150.67 148.33 45.17 42.44 11.39 9.61 1.41 1.26

CD(P=0.05) 1.677 2.437 1.535 1.285 0.57 0.65 0.043 0.065
Details of treatments are given in the text

Indira and Nair

J. Hortl. Sci.
Vol. 3 (2): 127-131, 2008



129

growth. Higher levels of potassium might have contributed
much to early flowering. This view was corroborated by
Jumbulingam et al (1975) who observed earlier flowering
and maturation with potassium application above 360 g
plant-1. Similar results were reported by Peters (1997) in
banana cv. Nendran in a red loam soil.

Yield attributes

Applied nitrogen markedly influenced the yield
attributing characters particularly number of hands and
fingers bunch-1 (Table 3). Nitrogen applied at 300 g plant1

produced more number of hands and fingers bunch-1.
Phosphorus applied at 200 and 300 g plant-1 exerted similar
effect on number of hands bunch-1 and number of fingers
bunch-1 during 1999-2000. Adequate supply of phosphorus
with N and K favoured the root proliferation and
penetration, covering very large root volume resulting in
high uptake of the nutrient. These factors might have
contributed to the favourable condition in the soil for
growth and development of the plant and thereby exerting
positive effect on the yield attributing factors. Number of

Table 3. Effect of nitrogen, phosphorus and potassium on yield components and yield

Main effects No. of hands bunch-1 No. of fingers bunch-1 Weight of bunch(kg)

1998-99 1999-2000 1998-99 1999-2000 1998-99 1999-2000

N
 1

7.06 7.33 111.78 111.94 7.69 6.66
N

2
8.50 8.44 131.39 128.89 11.68 9.68

N
3

9.33 9.11 142.56 138.50 12.11 11.03
CD(P=0.05) 0.328 0.510 3.283 6.093 0.244 0.255
P

1
7.83 7.78 120.83 118.72 9.52 8.37

P
2

8.33 8.50 129.94 128.72 10.81 9.39
P

3
8.72 8.61 134.94 131.89 11.05 9.61

CD(P=0.05) 0.328 0.510 3.283 6.093 0.244 0.255
K

1
7.72 7.83 121.44 119.72 9.64 8.29

K
2

8.39 8.39 130.28 128.50 10.82 9.24
K

3
8.78 8.67 134.00 131.11 10.99 9.83

CD(P=0.05) 0.328 0.510 3.283 6.093 0.244 0.255
Details of treatments are given in the text

Table 2.  Effect of nitrogen, phosphorus and potassium on crop duration

Main effects Days from plantingto shooting Days from  shooting to harvest Total crop duration(days)

1998-99 1999-2000 1998-99 1999-2000 1998-99 1999-2000

N
 1

291.72 297.11 110.44 109.50 402.17 406.06
N

2
281.11 283.89 106.44 106.17 387.56 390.06

N
3

274.17 273.00 106.11 104.11 380.28 377.11
CD(P=0.05) 2.537 1.839 2.521 2.514 2.711 2.587
P

1
283.89 286.89 107.83 107.72 391.72 394.61

P
2

281.50 285.11 107.61 106.61 381.11 391.72
P

3
281.61 284.43 107.56 105.44 389.17 389.88

CD (P=0.05) NS 1.839 NS NS NS 2.587
K

1
284.78 286.11 107.78 107.94 392.56 394.06

K
2

282.33 284.392 107.50 106.22 389.83 390.06
K

3
279.89 83.50 107.72 105.61 387.61 389.11

CD(P=0.05) 2.537 1.839 NS NS 2.711 2.587
Details of treatments are given in the text

hands and fingers bunch-1 was highest with the highest level
of potassium during 1998-1999. During the subsequent year
the increase was significant upto 400 g K

2
O plant-1. The

effect of potassium in improving the yield attributes in
banana was confirmed by many workers (Sheela, 1982;
Mustaffa, 1987 and Baruah and Mohan, 1992).

Yield
Nitrogen at 300 g plant-1 significantly increased the

bunch weight (Table 3). Increased availability and uptake
of nutrients at higher levels of N might have led to the better
expression of growth and yield attributes which ultimately
resulted in higher yield. Positive effect of phosphorus in
improving the yield was noticed up to 200 g P

2
O

5 
plant-1.

Bunch weight increased with increasing rate of potassium
up to 600 g K

2
O plant. Earlier reports also indicate positive

yield response of banana cv. Palayankodan to higher levels
of K (Sheela, 1982).

The interaction of nitrogen with phosphorus and
potassium was significant in 1998-99 and 1999-2000 (Table
4). Application of N

,
 P

2
O

5 
and K

2
O at 300:300:600 g plant-1,

Standardization of NPK requirement in banana

J. Hortl. Sci.
Vol. 3 (2): 127-131, 2008



130

300:300:400 g plant-1, 300:200:600g plant-1, 300:200:400 g
plant-1, 200:300:600g plant-1, 200:300:400g plant-1

200:200:600g plant-1 and 200:200:400g plant-1 produced
almost the same yield.  Application of N, P

2
O

5
 and K

2
O at

300:300:600g plant-1 showed a modest yield increase over
the treatment combination of N, P

2
O

5
 and K

2
O at

200:200:400 g plant-1.  So application of moderate dose of
N, P

2
O

5 
and K

2
O at 200:200:400g plant-1 year-1 is found to

be optimal for banana cv. “Njalipoovan”.  The response of
crops to fertilizer application depends on the status of
available plant nutrients in the soil and a low rating means
that crops on such soil should respond very readily to
nutrient application (Bains and Bhardwaj, 1976). In the
present study the soil nutrient status was low which explains
the better response to applied fertilizers. Applied nutrients
increased the availability of nitrogen, phosphorus,
potassium and micronutrients which resulted in favourable
growth condition in soil.

Quality attributes

Increase in the level of nitrogen significantly

Table 5. Effect of nitrogen, phosphorus and potassium on quality attributes

Main effect TSS (%) Acidity (%) Total sugars (%) Reducing sugars (%) Shelf life(days)
of factors 1998-99 1999-2000 1998-99 1999-2000 1998-99    1999- 2000 1998-99  1999-2000 1998-99 1999-2000
N

1
17.16 17.11 0.33 0.33 12.91 12.69 9.45 9.33 5.80 5.83

N
2

17.75 17.39 0.26 0.26 14.97 14.79 11.22 11.07 6.47 6.48
N

3
18.03 17.87 0.23 0.22 16.13 15.9 12.18 12.13 5.88 5.89

CD(P=0.05) 0.029 0.084 0.010 0.006 0.024 80.022 0.016  0.016 0.026 0.064
P

1
17.62 17.38 0.28 0.29 14.58 14.41 10.89 10.80 6.04 6.09

P
2

17.64 17.45 0.27 0.27 14.65 14.47 10.94 10.83 6.05 6.04
P

3
17.65 17.49 0.27 0.26 14.77 14.58 11.02 10.90 6.06 6.06

CD(P=0.05) NS NS NS NS NS NS NS NS NS NS
K

1
17.57 17.34 0.29 0.29 14.59 14.42 10.89 10.80 6.00 6.01

K
2

17.67 17.48 0.26 0.27 14.69 14.51 10.96 10.85 6.02 6.03
K

3
17.71 17.55 0.25 0.26 14.73 14.54 10.99 10.88 6.13 6.11

CD(P=0.05) 0.029 0.084 0.010 0.006 0.024 0.022 0.016 0.016 0.026 0.064
Details of treatments are given in the text

increased the TSS, total sugars and reducing sugars
(Table 5). Maximum values were recorded by the application
of nitrogen at 300g plant-1. But the acidity of ripe fruit tends
to decrease with the increasing rates of nitrogen. Shelf life
increased with increase in the level of nitrogen up to 200g
plant-1 beyond which there was a decrease.

Effect of different levels of potassium was also
significant in the case of TSS, total sugars, reducing sugars
and shelf life. TSS increased with the application of
potassium up to 400g plant -1during 1999-2000. Fruit acidity
decreased with the increasing level of potassium up to 400g
plant -1. Adequate supply of N and K might have ensured
optimal functioning of sucrose synthatase and suppression
of hydrolytic enzymes leading to build up of greater quantity
of sugars in proplastids (Nitsos and   Evans, 1969).

The applied phosphorus had no significant effect
on TSS, acidity, total sugars, reducing sugars and shelf life
of ripe fruits.

Economic analysis

Application of N, P
2
O

5 
and K

2
O at the rate of

200:200:400 g plant-1 proved profitable and showed
maximum BCR (1.96 and 1.84 for the first and second year
respectively) due to lower cost of cultivation and high yield
obtained (Table 6). The treatment combination of N, P

2
O

5

and K
2
O at lower levels recorded lowest economic returns.

The substantial increase obtained in bunch weight due to
treatment effects resulted in maximum returns thereby
enhancing BCR. In conclusion, the present study reveals
that application of N, P

2
O5 and K

2
O at the rate of

200:200:400 g plant-1 is appropriate for higher yield in
banana cv. “Njalipoovan” in the loamy sand soils of
Onattukara.

Table 4. Influence of N x P x K interaction on yield

P × K Yield (kg plant-1)

interaction 1998-1999 1999-2000

N 
1

N
2

N 
3

N 
1

N
2

N 
3

P
1
K

1
7.10 10.00 10.35 6.25 7.95 9.30

P
1
K

2
7.30 10.25 11.20 6.60 8.05 9.75

P
1
K

3
7.65 10.45 11.35 6.65 9.25 11.50

P
2
K

1
7.50 9.95 11.30 6.15 8.20  10.45

P
2
K

2
7.75 12.95 12.95 6.90 12.15 12.20

P
2
K

3
8.10 13.05 13.30 7.00 12.25 12.35

P
3
K

1
7.50 11.25 11.80 6.55 9.00 10.75

P
3
K

2
8.05 13.00 13.30 6.65 11.85 11.90

P
3
K

3
8.25 13.00 13.40 7.15 12.25 12.60

CD (P=0.05) 0.731 0.765
Details of treatments are given in the text

Indira and Nair

J. Hortl. Sci.
Vol. 3 (2): 127-131, 2008



131

REFERENCES

AOAC. 1977. Official and Tentative Methods Analysis,
Eleventh edition. Association of Official and
Analytical Chemists, Washington, U.S.A., 53-126

Bains, S.S. and Bhardwaj, B.L. 1976. Fertilizer management
for efficient crop production. Soil fertility - Theory
and Practice (ed. Kanwar, J.S). Indian Council of
Agricultural Research, New Delhi, p. 503

Baruah, P.J. and Mohan, N.K. 1992. Effect of K on yield
and yield attributing characters of Dwarf Cavendish
banana (Musa AAA group, Cavendish sub-group) in
Assam. Banana Newsletter, 15: 24-25

Geetha, K. 1998. Integrated plant nutrition system (IPNS)
for maximizing yield in banana, Musa (AAB group)
‘Nendran’. Ph.D thesis, Kerala Agricultural
University, Thrissur, p. 149

Geetha, K. and Nair, R.R. 2000. Integrated Plant Nutrition
System (IPNS) for banana. Ann. Agril. Res., 21:
499-503

Jambulingam, A.R., Ramaswamy, N. and Muthukrishnan,
C.R. 1975. Studies on the effect of potassium on
Robusta banana.  Potash  Rev., 27: 4-6

KAU.1996. Package of Practices Recommendations:
Crops 1996. Directorate of Extension Agricultural
University, Thrissur, pp. 179-185

Murray, D.B. 1960. The effect of deficiencies of the major
nutrients on growth and leaf analysis of banana.
Trop. Agri., 37: 97-106

Mustaffa, M.M. 1987. Growth and yield of Robusta banana
in relation to potassium nutrition.  J. Pot. Res., 3:
129-132

Nitsos, R.E. and Evans, H.J. 1969. Effect of univalent
cations on the activity of particulate starch
synthatase. Pl. Physiol., 44: 1260-1266

Panse, V.G. and Sukhatme, P.V. 1967. Statistical Methods
for Agricultural Workers, Second edition. Indian
Council of Agricultural Research, New Delhi, p. 381

Peters, D. 1997. Maximization of productivity by
rescheduling the nutrient application in banana
(Musa AB group Nendran). M.Sc. (Ag) thesis,
Kerala Agricultural University, Thrissur, p. 117

Ranganna, S. 1977. Manual of Analysis of Fruits and
Vegetable Products. Tata McGraw Hill Publishing
Company Ltd., New Delhi, p. 94

Sheela, V.L. 1982. Potassium nutrition in rainfed banana
Musa (AAB group) Palayankodan. M.Sc. (Hort)
thesis, Kerala Agricultural University, Thrissur,
p.109

Tisdale, S.L., Nelson, W.L., Beaton, J.D. and Havlin, J.L.
1995. Soil Fertility and Fertilizers, Fifth edition.
Prentice Hall of India Pvt. Ltd., New Delhi, p. 638

Varkey, P.A. and Pushkaran, K. 1992. Banana
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11: 41-76

(MS Received 22 January 2008, Revised 14 September 2008)

Table  6. Influence of N x P x K interaction on benefit: cost ratio

P × K Benefit: cost ratio

interaction 1998-1999 1999-2000

N 
1

N
2

N 
3

N 
1

N
2

N 
3

P
1
K

1
1.14 1.58 1.61 1.18 1.25   1.45

P
1
K

2
1.14 1.58 1.71 1.03 1.24  1.49

P
1
K

3
1.17 1.58 1.70 1.06 1.40 1.72

P
2
K

1
1.18 1.54 1.72 0.96 1.27 1.59

P
2
K

2
1.19 1.96 1.94 1.06 1.84 1.76

P
2
K

3
1.22 1.94 1.95 1.05 1.82 1.81

P
3
K

1
1.15 1.71 1.77 1.01 1.36 1.61

P
3
K

2
1.21 1.93 1.95 1.00 1.76 1.75

P
3
K

3
1.22 1.90 1.93 1.06 1.79  1.81

CD (P=0.05) 0.112 0.146
Details of treatments are given in text

Standardization of NPK requirement in banana

J. Hortl. Sci.
Vol. 3 (2): 127-131, 2008