Effect of Potassium Fertilization on Growth, Yield and Quality of... A.M. El-Bassiony Vegetable Research Department, National Research Center, Cairo, Egypt.

Effect of Potassium Fertilization on Growth, Yield and Quality of... A.M. El-Bassiony Vegetable Research Department, National Research Center, Cairo, Egypt.

Journal of Applied Sciences Research, 2(10): 780-785, 2006
© 2006, INSInet Publication
Effect of Potassium Fertilization on Growth, Yield and Quality of Onion Plants.
A.M. El-Bassiony
Vegetable Research Department, National Research Center, Cairo, Egypt.
Abstract: Two field experiments were carried out during the two successive seasons of 2003-2004 and
2004-2005 atthe Experimental Station ofNational Research Center in Shalakan (Qalubia Governorate) to study
the effect of soil application potassium sulfate (50, 100, 150 and 200 Kg/Fed.) and foliar application of
potassium oxide (1g/L) as a stimulated dose. Obtained data showed that the best plant growth (plant length,
number of leaves/plant and fresh weight of leaves) and highest yield and bulb quality were observed with soil
application of 200Kgpotassium sulfate. Foliar application of potassium oxide alsohas a positive effect on plant
growth, bulb yield and bulb quality.
Key words: Onion , potassium , foliar application, growth, yield , quality
INTRODUCTION
Table 1: Physical and chemical analysis of the soil at the experimental
sites.
A- Physical analysis
2003
2004
Soil texture
Clay loam
Clay loam
Clay(%)
47.80
48.30
Silt(%)
29.50
28.53
Sand (%)
21.34
21.63
B- Chemical analysis
Ca (meq/L.)
2.00
2.50
Mg (meq/L.)
2.50
2.60
Na (meq/L.)
3.65
3.20
K (meq/L.)
0.32
0.51
N (meq/L.)
141
183
P (meq/L.)
4.90
5.01
HCO3 (meq/L.)
2.00
2.30
CL (meq/L.)
1.78
3.06
Fe (p.p.m)
17.80
18.20
Zn (p.p.m)
1.10
1.05
Mn (p.p.m)
7.56
7.74
Cu (p.p.m)
13.55
14.71
Organic matter (%)
2.04
1.36
E.C (mmohs at 25 °C
1.55
1.05
PH.
7.77
7.87
Onion is considered one of the most important
vegetable crop in Egypt. Increasing productivity of onion
with good quality is an important target by the growers for
local market and exportation.
Chemical potassium fertilizer became a high
expensive fertilizer in Egypt, so farmers ignored using it.
Foliar fertilization is more economical than root
fertilization due to the higher degree of applied nutrients
more efficient [1]. Abd El-Al et al[2] found that Increasing
potassium as a soil application up to 150 Kg/fed. had a
significant effect on growth characters, i.e. plant height,
number of leaves/ plant, fresh and dry weight of whole
plant as well as total yield and its components. Also gave
the highest percentage of TSS, N. P. and K. Many
investigators reported that potassium affected plant
growth of onion[3-6]. In addition, potassium fertilizer
increased onion yield[7-9] and increased dry weight, K and
P uptake [10,11]. Potassium foliar spry increased plant
growth[12,13] on tomato;[14] on potatoes; yield and
quality [15,16] on tomato, as well as chemical
composition[12,13] on tomato.
The aim of this work is to improve yield and quality
by applying potassium fertilization as soil and foliar
application on onion plants.
200 Kg/Fed.) and foliar application of potassium oxide
K2O (1g/L) as a stimulated dose on growth and
productivity of onion plants. Onion seedlings cv. Giza 20
were transplanted on 15th and 17th of December 20032004 and 2004-2005 seasons respectively.
The design of the experiments was split-plot with
four replicates, where the potassium sulfate as a soil
application were distributed in the main plots and
potassium oxide foliar application were arranged in the
sub-plots.
Potassium sulfate was applied at two equal amounts,
the first dose was applied one month after transplanting
and the second dose added two month later. Foliar
application was applied at two times the first time was
MATERIALS AND METHODS
Two field experiments were carried out during the
two successive seasons of 2003-2004 and 2004-2005 at
the Experimental Station of National Research Center at
Shalakan (Qalubia Governorate) to investigate the effect
of soil application of potassium sulfate (50, 100, 150 and
Corresponding Author:
El-Bassiony, A. M., Vegitable Research Department, National Research Center, Cairo, Egypt.
E-mail: [email protected]
780
J. Appl. Sci. Res., 2(10): 780-785, 2006
one month after transplantingand the second time was ten
days later. The experimental plot contained six ridges,
each with 70cm width and 3.0 m long. The normal
agricultural treatments of the growing onion were
practiced as usually followed in the commercial
productionof onion. The physical and chemical properties
of the experimental soil are presented in Table (1).
During the vegetative growth period, samples of 8
plants were taken at 150 days after transplanting and the
plant length, number of leaves/ plant and fresh weight of
leaves and bulb were recorded.
At harvesting time (180 days from transplanting) the
yield of bulbs as ton/fed. was calculated. In the same time
samples of 10 bulbs from each experimental plot were
taken to record TSS(measured by hand Refractometer),
neck and bulb diameter.
Samples of leaves were oven dried at 70 oC, then fine
grounded and wetdigested. The nitrogen, phosphorus and
potassium contents were determined in dry leaves using
the method of Jackson [17], Troug and Mayers[18] and
Brown and Lilleland[19], respectively.
Data of the two experiments were subjected to
statistical analysis of variance according to the procedure
outlined by Gomez and Gomez[20].
level of significance. In the second season the interaction
had a significant effect on fresh weightof leaves and bulb.
The highest fresh weight of leaves and bulb recorded
when used potassium in the highest level (200 Kg/fed. as
soil application with potassium foliar application).
Plant length and leaf number increased with
increasing potassium level of soil application and
potassium foliar application but this increase faild to
reach the 5% level of significance.
Total yield and quality:
Effect of potassium soil application: Data presented in
Table (3) showed that potassium as soil application had a
significanteffect on neck diameter, bulb diameter, T.S.S.
and total yield. The highest values were recorded when
used 200 Kg potassium sulfate per Fed. The results were
true in both seasons. The results are accordance with
those obtained by Yadav et al[21] who found that the
highest potassium rate recorded the highest neck
thickness, bulb diameter, bulb fresh weight and bulb
yield[26-28] .
Effect of potassium foliar application: Results in
Table (3) indicated that potassium foliar application had
a significant effect on neck diameter, bulb diameter and
total yield but T.S.S. faild to reach the 5% level of
significance. The highest values of total yield (15.23 and
15.17 ton/fed.) were recorded with potassium foliar
application in the two seasons. These results were
coincided with those by Abdel-Ati[14], Agwah and
Mahmoud [15], Youssef et al[16].
RESULTS AND DISCUSSIONS
Growth characteristics:
Effect of potassium soil application: Data presented in
Table (2) clearly showed that potassium as soil
application had a significant effect on vegetative growth
characters i.e plant length, number of leaves and fresh
weightof leaves and bulb. The highest vegetative growth
characters were recorded with soil application of 200Kg
potassium sulfate/Fed. In the two seasons. The obtained
resultswere in a good accordance with those recorded by
Singh and Singh[5], Naidu et al[6], Yadav et al[21], Shrawan
et al[22], Al-Abdulsalam and Hamaiel[23].
Effect of the interaction: The interaction between
potassium as a soil or foliar application had no significant
effect on neck diameter, bulb diameter and T.S.S. The
results showed that the interaction significantly affected
the total yield. The highest values of total yield were
recorded with 200Kg/fed. as soil application and
potassium foliar application, in the two seasons.
Effect of potassium foliar application: Potassium foliar
application had a significant effect on plant length and
fresh weight of leaves and bulb (Table 2), but had no
significant effect on leaf number per plant. The positive
effect of potassium oxide foliar application on growth
parameters may be due to that potassium increased
efficiency of the plant for utilization nitrogen which is
essential for plant growth as well as other processes
related to nitrogen metabolism[24].
Similar results were obtained by Adam et al. [12],
Daewesh [13], Hassan [25].
Chemical composition:
Effect of potassium soil application: Data in Table (4)
reported that leaf and bulb dry weight was significantly
influenced by potassium soil application in the two
seasons. The heaviest leaf and bulb dry weight was
obtained with 200 Kg/fed. potassium as soil application in
both seasons.
Nitrogen and potassium percentage (Table 5) were
significantly affected by potassium soil application but
phosphorus percentage failed to reach the 5% level of
significancein the two seasons. 200 Kg/Fed. potassium as
soil application recorded the highest values of nitrogen
and potassiumpercentage. There was no significanteffect
between 200 and 150 Kg/Fed. on nitrogen percentage in
the first season.
Effect of the interaction: Results presented in Table (2)
indicated that in the first season fresh weight only was
significantly affected by the interaction, but plant length,
leaf number and fresh weight of bulb faild to reach the 5%
781
J. Appl. Sci. Res., 2(10): 780-785, 2006
Table 2: Effect of potassium fertilizers on vegetative growth of onion plants during 2003-2004 and 2004-2005 seasons.
Treatments
2003-2004
2004-2005
--------------------------------------------------------------------------------------------------------------------------------------Plant
No. of
Fresh weight (g)
Plant
No. of
Fresh weight (g)
length (cm) leaves/plant -------------------------------length (cm) leaves/plant -------------------------------Leaves
Bulb
Leaves
Bulb
Soil application of potassium sulfate (Kg/Fed.)
50 Kg
44.25
7.25
22.27
59.23
42.67
7.5
21.82
65.9
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------100 Kg
53
9.25
38.26
129.72
50.67
8.83
35.81
126.29
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------150 Kg
54.5
9.5
44.42
134.5
51
9.16
40.52
131.37
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------200 Kg
59.75
12
67.17
182.33
57.33
10.83
62.78
180.51
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------LSD at 5%
4.23
2.21
10.91
33.43
5.28
2.01
8.12
20.65
Foliar application of potassium oxide (1g/L)
Check
49.75
9.13
37.79
111.55
48.25
9
34.86
110.54
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------K2 O
56
9.88
48.27
141.34
52.58
9.16
45.61
141.5
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------LSD at 5%
4.49
NS
6.35
20.82
3.62
NS
6.21
16.72
Interaction
Check
40
6
20.64
50.87
40.66
7.33
19.01
52.38
50 Kg
K2 O
48.5
8.5
23.89
67.59
44.67
7.67
24.62
79.42
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Check
52.5
9
35.59
123.19
50.33
9
34.09
122.54
100 Kg
K2 O
53.5
9.5
40.92
136.25
51
8.67
37.54
130.05
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Check
52
10
40.8
114.73
50
9.33
37.13
115.52
150 Kg
K2 O
57
9
48.04
154.26
52
9
43.92
147.21
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Check
54.5
11.5
54.13
157.41
52
10.33
49.21
151.73
200 Kg
K2 O
65
12.5
80.22
207.25
62.67
11.33
76.36
209.3
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------LSD at 5%
NS
NS
11.28
NS
NS
NS
12.42
23.43
* Check = water foliar application
Table 3: Effect of potassium fertilizers on yield and quality of onion plants during 2003-2004 and 2004-2005 seasons.
Treatments
2003-2004
2004-2005
--------------------------------------------------------------------------------------------------------------------------------------T.S.S. Neck
Bulb
Total yield
T.S.S. Neck
Bulb
Total yield
diameter (cm) diameter (cm) (ton/fed.)
diameter (cm) diameter (cm) (ton/fed.)
Soil application of potassium sulfate (Kg/Fed.)
50 Kg
12.25
1.48
5.1
10.49
11.83
1.53
4.97
10.85
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------100 Kg
12.25
1.83
6.69
14.01
12.5
1.85
6.59
13.99
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------150 Kg
13.75
1.93
6.93
15.3
13
1.9
6.82
15.04
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------200 Kg
13.5
2.23
7.45
17.62
13.33
2.25
7.42
17.27
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------LSD at 5%
0.59
0.11
1.12
1.33
0.9
0.18
0.5
1.54
Foliar application of potassium oxide (1g/L)
Check
12.63
1.78
6.09
13.48
12.42
1.78
6.09
13.41
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------K2 O
13.25
1.95
6.99
15.23
12.92
1.99
6.81
15.17
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------LSD at 5%
NS
0.15
0.73
1.66
NS
0.17
0.56
1.26
Interaction
Check
11.5
1.45
4.35
10.07
11.33
1.43
4.5
10.47
50 Kg
K 2O
13
1.5
5.85
10.92
12.33
1.63
5.43
11.22
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Check
12
1.75
6.58
13.64
12
1.8
6.55
13.84
100 Kg
K 2O
12.5
1.9
6.8
14.39
13
1.9
6.63
14.14
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Check
15
1.8
6.35
13.85
14
1.8
6.4
13.3
150 Kg
K 2O
12.5
2.05
7.5
16.76
12
2
7.23
16.78
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
782
J. Appl. Sci. Res., 2(10): 780-785, 2006
Table 3: Continued
Check
12
2.1
7.1
16.38
12.33
2.07
6.9
16.01
200 Kg
K 2O
15
2.35
7.8
18.85
14.33
2.43
7.93
18.53
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------LSD at 5%
NS
NS
NS
2.15
NS
NS
NS
2.02
* Check = water foliar application
Table 4: Effect of potassium fertilizers on dry weight of onion plants during 2003-2004 and 2004-2005 seasons.
Treatments
2004-2005
2003-2004
--------------------------------------------------------------------------------------------Bulb
Leaves
Bulb
Leaves
Soil application of potassium sulfate (Kg/Fed.)
50 Kg
7.30
3.02
7.53
2.75
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------100 Kg
15.75
4.70
16.29
4.46
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------150 Kg
19.82
4.86
16.65
4.48
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------200 Kg
23.47
6.07
22.51
5.93
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------LSD at 5%
4.06
0.97
5.14
1.27
Foliar application of potassium oxide (1g/L)
Check
14.78
4.24
13.68
4.13
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------K2 O
18.39
5.08
17.81
4.68
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------LSD at 5%
2.55
0.43
3.04
NS
Interaction
50 Kg
Check
6.16
2.14
5.81
2.28
K 2O
8.44
3.91
9.26
3.22
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------100 Kg
Check
14.68
4.54
14.87
4.38
K 2O
16.83
4.86
17.70
4.54
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------150 Kg
Check
18.55
4.70
15.47
4.21
K 2O
21.10
5.02
17.83
4.75
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------200 Kg
Check
19.74
5.59
18.57
5.65
K 2O
27.21
6.56
26.45
6.21
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------LSD at 5%
NS
NS
NS
NS
* Check = water foliar application
coincided with those of Adam et al[12], Daewesh [13], and
Hassan[25].
Such results were in agreement with the results
reported by Geetha et al[10], Nagaich et al[11] who found
that uptake of phosphorus and potassium was highest with
increasing potassium level.
Effect of the interaction: The data in Table (4) reported
that the interaction between soil and foliar potassium
application had no significant effect on dry weight of
leaves and bulb.
The interaction between soil and foliar
potassium application had a significant effect on
nitrogen and potassium percentage (Table 5). The
highest values were recorded when use 200 or
150Kg /fed. potassium as soil fertilizer with
potassium foliar application. However, phosphorus p
ercentage was not significantly influenced by the
interaction in the two seasons.
Effect of potassium foliar application: The results
in Table (4) indicated that, potassium foliar
application had a significant effect on dry weight
of leaves and bulb in the first season and bulb dry
weight only in the second season. However, leaf dry
weightin the second season faild to reach the 5% level of
significance.
The heaviest dry weight of leaves and bulb were
obtained by potassium foliar application.
Nitrogen and potassium percentage increased
significantly with potassium foliar application in the two
seasons (Table 5). On the other hand, potassium foliar
application had no significant effect on phosphorus
percentage in both seasons. The obtained results
Conclusion: From the obtained results, it can be
concluded that under the same condition, the best
treatment for increasing productivity of onion plants
is using 200 Kg/Fed. potassium sulfate as soil
783
J. Appl. Sci. Res., 2(10): 780-785, 2006
Table 5: Effect of
Treatments
potassium fertilizers on
chemical composition of onion leaves during 2003-2004 and 2004-2005 seasons.
2004-2005
2003-2004
--------------------------------------------------------------------------------------------N%
P%
K%
N%
P%
K%
Soil application of potassium sulfate (Kg/Fed.)
50 Kg
1.57
0.34
1.65
1.74
0.35
1.67
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------100 Kg
1.58
0.37
1.70
1.78
0.36
1.72
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------150 Kg
1.69
0.37
1.75
1.82
0.32
1.73
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------200 Kg
1.71
0.37
1.80
1.88
0.35
1.75
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------LSD at 5%
0.03
NS
0.02
0.03
NS
0.01
Foliar application of potassium oxide (1g/L)
Check
1.60
0.36
1.69
1.73
0.33
1.70
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------K2 O
1.66
0.37
1.76
1.87
0.36
1.74
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------LSD at 5%
0.05
NS
0.04
0.07
NS
0.02
Interaction
50 Kg
Check
1.52
0.34
1.63
1.73
0.33
1.68
K 2O
1.61
0.33
1.66
1.75
0.37
1.66
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------100 Kg
Check
1.55
0.37
1.67
1.73
0.34
1.70
K 2O
1.59
0.37
1.72
1.82
0.37
1.73
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------150 Kg
Check
1.64
0.36
1.69
1.68
0.32
1.69
K 2O
1.73
0.38
1.81
1.95
0.31
1.77
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------200 Kg
Check
1.68
0.35
1.76
1.78
0.33
1.72
K 2O
1.74
0.38
1.84
1.97
0.37
1.78
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------LSD at 5%
0.05
NS
0.02
0.04
NS
0.01
* Check = water foliar application
application with the potassium foliar application as a
stimulating dose.
5. Singh R.B. and S.B. Singh, 2000. Significance of
nitrogen, phosphorus andpotassium on onion (Allium
cepa L.). raised from onion sets (bulblets). Vegetable
Science 27 (1): 88-89.
6. Naidu A.K., J.P. Tiwari, S.K. Dwivedi and S.K.
Saxena, 2000. Effect of various levels of N, P, and K
on physiological growthdeterminants of productivity
in garlic (Allium sativum Linn.). Vegetable Science,
27 (2): 165-167.
7. Singh, S.P. and C.R. Mohanty, 1998. A note on the
effect of nitrogen and potassium on the growth
and yield
of onion. Orissa Journal of
Horticulture 26 (2): 70-71. (c. a. CAB Abstr.).
8. Guo, X.S.,C.Y. Liu and W.J. Wang,1999. The effect
of K fertilizer on the yield, quality and nutrient
uptake of onion. China Vegetables 2: 12-14.
9. Al-Moshileh, A.M., 2001. Effect of nitrogen,
phosphorus and potassium fertilizers on onion
productivity in central region of Saudi Arabia. Assiut
Journal of Agricultural Science, 32 (1): 291-305.
10. Geetha, K., A.S. Raju and M. Shanti, 1999. Effect of
farmyard manure and potassium on K nutrition and
yield of onion at different stage of growth. Journal of
Research ANGRAU, 27 (1-2): 18-23.
REFERENCES
1. Ashour, S.A. and S.H. Sarhan, 1998. Effect of
potassium foliar application on growth and
yield of potato (Solanum tuberosum, L.). Journal
of Agriculture Science, Mansoura University
23 (9): 3991-3998.
2. Abd El-Al, F.S., M. R. Shafeek, A.A. Ahmed and
A.M. Shaheen, 2005. Response of growth and yield
of onion plants to potassium fertilizer and humic
acid. Journal of Agriculture Science, Mansoura
University 30 (1): 315-326.
3. Singh, T., S.B. Singhand B.N. Singh, 1989. Effect of
nitrogen, potassium and green manuring on growth
and yield of rainy season onion (Allium cepa L.).
Narendra Deva Journal of Agricultural Research
4 (1): 57-60. (c. a. CAB Abstr.).
4. Baloch, M.A., A.F. Baloch, B. Gohram, A.H. Ansari
and S.M. Qayyum, 1991. Growth and yield response
of onion to different nitrogen and potassium fertilizer
combination levels. Sarhad Journal of Agricultural,
7 (2): 63-66. (c. a. CAB Abstr.).
784
J. Appl. Sci. Res., 2(10): 780-785, 2006
11. Nagaich, K.N., S.K. Trivedi, L. Rajesh and R. Lekhi,
1999. Effect of sulpher and potassium
fertilization in onion (Allium cepa L.). Journal of
Horticulture 12 (1): 25-31.
12. Adam, S.M., E.H. Abou El-Salehein and A.M. Abd
Alla, 1996. Effect of N and K fertilizers as
foliar spray on tomatoes under greenhouse
conditions.
Zagazig Journal of Agricultural
Research 23 (4): 629-640.
13. Darwesh, F.A.M., 1996. Evaluation of some
protective techniques for use in tomato production
under low and high temperature conditions. M. Sc.
Thesis, Fac. Agric. Cairo Univ. Cairo, Egypt.
14. Abdel-Ati, Y.Y., 1998. Potato yield and quality as
affected by nitrogen and potassium application rates.
Journal of Agricultural Science. Mansoura Univ.,
23 (5): 2357-2368.
15. Agwah, E.M.R. and H.A.F. Mahmoud, 1994. Effect
of some nutrients, sucrose and cultivars on tomato
fruit set and yield. Bull. of Faculty of Agricultural
Univ. Cairo., 45 (1): 137-148.
16. Youssef, A.M., A.H.M. El-Fouly, M.S. Youssef and
S.A. Mohamedien, 2001. Effect of using organic and
chemical fertilizers in fertigation system on yield and
fruit quality of tomato. Egypt. Journal of
Horticulture, 28 (1): 59-77.
17. Jakson, M.L., 1958. Soil chemical analysis prentice.
Hall, Inc. enlewood cliffs, N. J. Library of Congress.
U.S.A.
18 Troug, E. and A.H. Mayer, 1939. Improvement in the
denies colorimetric method for phosphorus and
arsenic. Indian Engineers chemical annual Ed.,
1: 136-139.
19. Brown, J.D. and O. Lilleland, 1946. Rapid
determination of potassium and sodium in plant
material and soil extract by flame photometry. Proc.
Amer. Hort. Sci., 38: 341-364.
20. Gomez, K.A. and A.A. Gomez, 1984. Statistical
procedures for Agricultural Research. Seconded.
Willey Inter Science Pulb., PP. 357-423.
21. Yadav, R.L., N.L. Sen and B.L. Yadave, 2003.
Response of onion to nitrogen and potassium
fertilization under semi-arid condition of
Rajasthan. Indian Journal of Horticultural,
60 (2): 176-178. (c. a. CAB Abstr.).
22. Shrawan, S., P.K. Yadav and S. Balbir, 2004. Effect
of nitrogen and potassium on growth and yield of
onion (Allium cepa L.) cv. Pusa Red. Haryana Journal
of Horticultural Sciences 33 (3-4): 308-309. (c.a.
CAB Abstr.).
23. Al-Abdulsalam, M.A. and A.F. Hamaiel, 2004.
Effect of planting dates and compound fertilizers on
growth, yield and quality of Hassawi onion under AlHassa oasis. Scientific Journal of King Faisal
University Saudi Arabia, 5 (1): 65-79.
24. Forshey, C.G. and M. Makee, 1970. Effects of
potassium deficiency on nitrogen metabolism of fruit
plants. J. Amer. Soc. Hort. Sci., 95 (6): 727.
25. Hassan Z.F.F., 2002. Effect of some sources of
organic manure and levels of potassium on growth,
yield, quality and chemical composition of pepper
(Capsicum annuum L.). Ph. D. Fac. Agric. Cairo
Univ. Cairo, Egypt.
26. Mohanty, B.K. and J.N. Das, 2002. Response of
rabbi onion cv. Nasik Red to nitrogen and potassium
fertilization. Vegetable Science, 28 (1): 40-42.
27. Mandira, C. and A.H. Khan, 2003. Effect on nitrogen
and potassium on growth, yield and yield attributesof
onion. New Agriculturist Bioved Research Society,
Allahabad, India, 14 (1-2): 9-11. (c. a. CAB Abstr.).
28. Qiao, H., X. Wang; A. Zhu and Z. Gu, 2005. Effect
of decreasing chemical fertilizer application and
applying organic fertilizer on yield and quality
of welsh onion. Acta Agriculture Shanghai, China,
21 (2): 49-52. (c. a. CAB Abstr.).
785