BIBLIOGRAPHY GASIGAS, KIRBY D. APRIL ...
BIBLIOGRAPHY
GASIGAS, KIRBY D. APRIL 2012. Potato (Solanum tuberosum L.) Growth,
Yield, and Tuber Dry Matter as Affected by Nitrogen and Potassium Fertilizer Levels.
Benguet State University, La Trinidad, Benguet.
Adviser: Percival B. Alipit, PhD.
ABSTRACT
The study was conducted at the Horticulture Experiment Field, Benguet State
University, La Trinidad, Benguet from November 2011 to February 2012 to determine the
effects of different rates of nitrogen and potassium fertilizer application on the growth,
yield, and tuber dry matter content of potato and on the economics of growing the crop.
Results reveal that although vegetative growth and yield were not significantly
affected by the fertilizers applied, marketable yield at 24.83 t/ha and return on investment
at 62.78 % were greater with the application of 210-140-140 kg N-P2O5-K2O/ha. Tuber dry
matter content was significantly higher with the application of 140-140-210 kg N-P2O5-
K2O/ha.
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
RESULTS AND DISCUSSION
Plant Height
Results revealed that there were no significant differences among the treatments
with regards to final plant height of as shown in Table 1. The height of the treatment plants
ranged from 83.15 to 83.90 centimeters.
Haulm weight
Table 2 shows that there were no significant differences in the haulm weight of the
treatment plants. However, plants applied with 210-140-140 kg N-P2O5-K2O/ha had
heavier haulms.
Table 1. Plant height
TREATMENT
MEAN
(kg N-P2O5-K2O/ha)
(cm)
210-140-140
83.50a
140-140-140
83.25a
140-140-210
83.90a
210-140-210
83.15a
140-140-140 +3 t/ha chicken dung
83.75a
Means followed by a common letter are not significantly different at 5% level (DMRT).
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Table 2. Haulm weight
TREATMENT
MEAN
(kg N-P2O5-K2O /ha)
(g)
210-140-140
417.49a
140-140-140
376.32a
140-140-210
386.27a
210-140-210
388.21a
140-140-140 +3 t/ha chicken dung
392.96a
Means followed by a common letter are not significantly different at 5% level (DMRT).
Days to Maturity
Plants applied with either 140-140-140 or 140-140-210 kg N-P2O5-K2O/ha
significantly matured earlier at 89 days as shown in Table 3.
Table 3. Days to maturity
TREATMENT
MEAN
(kg N-P2O5-K2O/ha)
210-140-140
90.50a
140-140-140
89.00b
140-140-210
89.00b
210-140-210
90.50a
140-140-140 +3 t/ha chicken dung
91.00a
Means followed by a common letter are not significantly different at 5% level (DMRT).
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Weight of Classified Tubers
In Table 4, there were no significant differences in the weight of marketable tubers
classified into sizes as affected by the fertilizers applied. However, application of 140-140-
210 kg N-P2O5-K2O/ha tended to increase the weight of bigger size tubers.
Table 4. Weight of tubers classified according to sizes
CLASSIFICATION
(kg/5 m2 plot)
TREATMEN
MARBL
SMAL
ME
BIG L
XL
SUPE
JUMB
T
E
L
D
R
O
(kg N-P2O5-
K2O/ha)
210-140-140
1.13a
1.54a
2.46a 0.93
1.27
1.43
1.06a
2.67a
140-140-140
1.20a
1.71a
2.09a a
a
a
1.26a
2.31a
140-140-210
0.85a
1.08a
2.53a 0.79
1.02
1.06
1.28a
2.76a
210-140-210
1.14a
1.53a
2.54a a
a
a
1.25a
2.26a
140-140-140
1.06a
1.58a
2.61a 1.05
0.98
1.28
0.96a
1.68a
+3 t/ha
chicken dung
a
a
a
1.19
1.18
0.72
a
a
a
1.22
1.54
1.28
a
a
a
Means followed by a common letter within a column are not significantly different at 5%
level (DMRT).
Legend: Marble = 37-43g, small= 44-50g, medium= 51-77g, big= 78-84g, large= 85-98g,
extra large= 99-105g, super= 106-125g, jumbo 126g-above
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Number of Classified Tubers
Table 5 shows that there were no significant differences in the number of
marketable tubers classified into sizes. However, greater number of extra large tubers was
obtained with the app1ication of 210-140-140 kg N-P2O5-K2O /ha, super tubers with 140-
140-210 kg N-P2O5-K2O/ha and jumbo tubers with 140-140-140 kg N-P2O5-K2O/ha.
Table 5. Number of tubers classified according to sizes
TREAT
CLASSIFICATION
MENT
(per 5 m2 plot)
(kg N-P2O5- Marble Small
M
B
L
XL
Super Jumbo
K2O/ ha)
210-140-140 45.50a
36.25a 38.75a
14.25a 14.50a 14.25a 9.50a
17.25a
140-140-140 47.00a
37.00a 35.00a
10.25a 12.00a 11.75a 12.00a 15.25a
140-140-210 33.25a
23.25a 39.25a
13.50a 10.75a 12.50a 12.75a 19.50a
210-140-210 46.25a
35.00a 40.24a
14.75a 13.25a 7.50a
11.50a 14.50a
140-140-140 45.50a
33.50a 41.25a
15.50a 17.50a 13.00a 8.00a
13.75a
+3 t/ha
chicken
dung
Means followed by a common letter within a column are not significantly different at 5%
level (DMRT).
Legend: Marble = 37-43g, small= 44-50g, medium= 51-77g, big= 78-84g, large= 85-98g,
extra large= 99-105g, super= 106-125g, jumbo 126g-above
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Tuber Yield
There were no significant differences in the marketable, non-marketable and total
yield as affected by rates of fertilizers applied as shown in Table 6. However, greater
marketable tubers were noted with the application of higher nitrogen and lower phosphorus
and potassium levels at 210-140-140 kg N-P2O5-K2O/ha.
Plants applied with 210-140-140 kg N-P2O5-K2O/ha had better haulm development
for photosynthesis, thus resulting to higher marketable tuber yield.
Computed Marketable Yield
There were no significant differences in the computed yield as shown in Table 7.
However, the highest computed marketable yield was obtained from plants applied with
210-140-140 kg N-P2O5-K2O/ ha at 24, 835.00 kg/ha.
Table 6. Tuber yield
TREATMENT
YIELD (kg/5 m2 plot)
(kg N-P2O5-
K2O/ha)
MARKETABLE
NON-
TOTAL
MARKETABLE
210-140-140
12.42a
0.48a
12.89a
140-140-140
11.49a
0.51a
12.00a
140-140-210
11.79a
0.47a
12.26a
210-140-210
11.88a
0.49a
12.28a
140-140-140 +3 t/ha 11.92a
0.59a
12.51a
chicken dung
Means followed by a common letter within a column are not significantly different at 5%
level (DMRT).
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Table 7. Computed marketable yield
TREATMENT
MEAN
(kg N-P2O5-K2O/ha)
(kg/ha)
210-140-140
24, 835.00a
140-140-140
22, 975.00a
140-140-210
23, 575.00a
210-140-210
23, 580.00a
140-140-140 +3 t/ha chicken dung
23, 845.00a
Means followed by a common letter are not significantly different at 5% level (DMRT).
Tuber Dry Matter Content
Table 8 shows that significantly higher dry matter content of tubers at 24.16% was
obtained with the application of lower nitrogen and phosphorus and higher amount of
potassium at 140-140-210 kg N-P2O5-K2O/ha. This dry matter meets the standard for
processing potatoes.
Dry matter content of potatoes for processing is of great importance. Dry matter
content of potatoes is acceptable when it is from 17.19% to 29.99% while the least
acceptable range is from 15.10% to 16.44% dry matter (Ludwig, 1985). HARRDEC (1996)
emphasized also that potatoes should have a dry matter of 21% for processing for best
quality.
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Table 8. Tuber dry matter content
TREATMENT
MEAN
(kg N-P2O5-K2O/ha)
(%)
210-140-140
22.32b
140-140-140
22.64b
140-140-210
24.16a
210-140-210
22.64b
140-140-140 +3 t/ha chicken dung
22.58b
Means followed by a common letter are not significantly different at 5% level (DMRT).
Soil Analysis
The composition of the soil in the experimental field prior to application of different
fertilizer rates is shown in table 9.
Table 9. Soil analysis
N, %
P, ppm
K, ppm
OM, %
pH
Initial
0.05
94
300
1.0
5.91
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Meteorological Data
The meteorological data during the study period is shown in Table 10. Rainfall
ranged from 0.72 mm to 3.40 mm; relative humidity, 83.63% - 87.00%; minimum
temperature, 10.7 oC - 15.50 oC; maximum temperature, 23.90 oC – 24.72 oC; and sunshine
duration, 267.16 min – 304.18 min.
Cost and Return Analysis
Table 11 shows that the highest return on investment at 62.78 % was obtained
with the application of 210-140-140 kg N-P2O5-K2O/ha followed by the application of
140-140-140 kg N-P2O5-K2O/ha.
Table 10.Meteorological data
Month
Rainfall
RH (%)
Temperature (0C)
Sunshine
(mm)
Min
Max
duration
(min)
November
0.72
87.00
15.50
24.72
267.16
December
0.72
86.90
14.48
24.66
227.71
January
1.40
83.63
13.10
24.15
296.95
February
3.40
86.60
10.70
23.9
304.18
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Table 11. Cost and return analysis
TREATMENT
ITEM
T1
T2
T3
T4
T5
Marketable
12.42
11.49
11.79
11.88
11.92
yield
kg/
5m2 plot
Inputs
Labor
20.50
20.50
20.50
20.50
20.50
Planting
66.67
66.67
66.67
66.67
66.67
materials
Fertilizers
17.86
15.50
17.86
20.21
27.50
Insecticides
25.67
25.67
25.67
25.67
25.67
Fungicides
37.50
37.50
37.50
37.50
37.50
Total
Expenses
168.20
165.84
168.20
170.55
178.04
Gross sales
273.80
256.22
245.10
252.58
228.95
Net income
105.6
90.38
76.90
82.03
49.09
ROI (%)
62.78
54.50
45.72
48.10
27.57
Rank
1
2
4
3
5
Legend (kg N-P2O5-K2O/ha): T1=210-140-140, T2=140-140-140, T3=140-140-210,
T4=210-140-210, T5=140-140-140 + 3 t/ha chicken dung
The Php selling price was: Marble= 2.00 per piece, and per kilogram: Small= 8.00,
Medium=10.00, Big=12.00, Large=15.00, Extra large=18.00, Super=20 and Jumbo=25
Pictorial Presentation
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Figure 1. Overview of the experiment field two weeks from planting
Figure 2. Tuber Yield
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
2a. Tubers classified according to sizes from plants applied
with 210-140-140 kg N-P2O5-K2O/ha
2b. Tubers classified according to sizes from plants applied
with 140-140-140 kg N-P2O5-K2O/ha
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
2c. Tubers classified according to sizes from plants applied
with 140-140-210 kg N-P2O5-K2O/ha
2d. Tubers classified according to sizes from plants applied
with 210-140-210 kg N-P2O5-K2O/ha
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
2e. Tubers classified according to sizes from plants applied with
140-140-140 kg N-P2O5-K2O/ha plus 3 t/ha chicken dung
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary
The study was conducted primarily to determine the effect of varying rates nitrogen
and potassium on the growth and yield performance of potato, establish the appropriate
level of nitrogen and potassium that will enhance growth, yield and tuber dry matter
accumulation and determine the economics of using different fertilizer rates in potato
production. It was conducted at the Horticulture Experiment Field, Benguet State
University, La Trinidad, Benguet from November 2011 to February 2012.
Growth in plant height and haulm weight did not significantly differ among
treatment plants and so with the number and weight of tubers classified according to sizes
including yield. However, marketable yield tended to increase at 24.83 t/ha with the
application of higher nitrogen rate at 210-140-140 kg N-P2O5-K2O/ha. Tuber dry matter at
24.16% was significantly higher with higher potassium level at 140-140-210 kg N-P2O5-
K2O/ha. The return on investment was highest at 62.78% with the application of 210-140-
140 kg N-P2O5-K2O/ha.
Conclusion
Based on the results, it is concluded that application of 210-140-140 kg N-P2O5-
K2O/ha could increase the marketable yield and correspondingly increase the return on
investment. Higher dry matter content of tubers could be obtained with the application of
140-140-210 kg N-P2O5-K2O/ha.
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Recommendation
It is therefore recommended to apply 210-140-140 kg N-P2O5-K2O/ha on potato to
have a higher marketable yield and return on investment. For potato intended for
processing, application of 140-140-210 kg N-P2O5-K2O/ha could increase the tuber dry
matter content.
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
LITERATURE CITED
BEUKEMA, H. P. and D. E. VAN DER ZAAG. 1979. Potato improvement: Some factors
and facts. International Agriculture Center, Wageningen, The Netherlands. P. 222.
BRADY, N. C. 1985. The Nature and Properties of Soils. New York, McMillan
BUGAOAN, R. A. 1977. Methods of planting and rate of application of NPK on the growth
and yield of Irish potato. (Unpub) BS Thesis. Benguet State University, La
Trinidad, Benguet. P. 55.
CALLADO, E. B. 2011. Growth and yield of rooted potato stem cuttings as affected
by different inorganic fertilizers under BSU La Trinidad, Benguet condition.
(Unpub) BS Thesis. Benguet State University, La Trinidad, Benguet. Pp. 33-34.
COX, J. F. 1930. Crop Production and Management. USA. Press of Brownworth Co., Inc
P. 281.
DEVLIN, R. H.1977. Plant Physiology. New York: Van Nastard Company. Pp. 56-57.
EPSTIEN, E. and A. J. BLOOM. 2005. Mineral Nutrition of Plants: Principles and
Perspective. 2nd Edition.Sundeland, Massachussets. Sinauer Associates, Inc.
Publishers. P. 59.
HARRDEC. 1996. Highland Potato Technoguide. Highland Agriculture Research and
Development and Consortium. Benguet State University, La Trinidad, Benguet. 3rd
Ed. P. 43.
HARRIS, P. M. 1982. The Potato Crops. The Scientific Basis for Improvement. New York.
P. 177.
HAUSENBUILLER, R. L. 1972. Soils. 3rd Ed. Bubsequa, Lawa, WMC, Brown Publishing
Co., Ltd. P. 57
KEMLER, G. 1980. Potassium Deficiency in Soils of the Tropics as Constraint to
Food Production. In: Soils Related Constraint in the Tropics. P. 102.
KNOTT, I. R. and DEANON, J R. 1967. Vegetable Production in Southeast Asia.
University of the Philippines, Los Baňos, Laguna.P. 283.
LUDWIG, J.W. 1985. Quality Standards for the Processing Industry. International
Agricultural Center, Netherlands. P. 20.
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
MARTIN and LEONARD. 1970. Principle of Field Crop Production. 2nd Ed. New
York. McMillan Co., P. 856.
MIGUEL, B.B. 1996. Effects of stem number and kind of fertilizer on the growth and yield
of potato. (Unpub) BS Thesis. Mountain State Agricultural College, La Trinidad,
Benguet. P. 25.
NATH, R. 1993. Modern Pant Physiology. Kalyani Publishers. India. P. 202.
PHILIPPINE COUNCIL FOR AGRICULTURE AND RESOUCES RESEACH AND
DEVELOPMENT. 1985. Benguet Tecnoguide for Potato: Laguna: PCARRD. Pp.
1-3, 8-1.
SHRESTHA, S. S. 1997. Fertilization: effect on agronomic and processing traits of
potato varieties. (Unpub) MS Thesis. Benguet State University La Trinidad,
Benguet. P. 15.
SMITH, O. 1977. Potatoes: Production, Storing, Processing. The Avi Publishing
Company, Inc. Westport, Connecticut. Pp. 83-84.
THOMPSON, N. B. and, N. C. KELLY. 1982. Vegetable Crop. 5th Ed. New Delhi. Tata
McGrawhill Publishing Company, Ltd. Pp. 88-89, 372.
TIMM, H., J. C. BISHOP and V. H. SCHWEERS. 1963. Growth, Yield and Quality of
White Rose Potatoes as affected by Plant Population and Levels of Nitrogen.
American Potato Journal. P. 40, 1-8
TINDALL, H. D. 1983. Vegetable in the Tropics. Macmillan Education LDT. Hongkong.
P. 376.
TOOLANGI, T. K., 1996. Potatoes factors affecting dry matter. Access
at http//www.dpi.vic.gov.au/DPI/nreninf.nsf/FID/ on November, 2006.
VOTOUPAL, B. 1977. High Nutrients Application Rates and the table Quality of the ‘Cira’
Cultivar of Early Potatoes. P. 5.
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
GASIGAS, KIRBY D. APRIL 2012. Potato (Solanum tuberosum L.) Growth,
Yield, and Tuber Dry Matter as Affected by Nitrogen and Potassium Fertilizer Levels.
Benguet State University, La Trinidad, Benguet.
Adviser: Percival B. Alipit, PhD.
ABSTRACT
The study was conducted at the Horticulture Experiment Field, Benguet State
University, La Trinidad, Benguet from November 2011 to February 2012 to determine the
effects of different rates of nitrogen and potassium fertilizer application on the growth,
yield, and tuber dry matter content of potato and on the economics of growing the crop.
Results reveal that although vegetative growth and yield were not significantly
affected by the fertilizers applied, marketable yield at 24.83 t/ha and return on investment
at 62.78 % were greater with the application of 210-140-140 kg N-P2O5-K2O/ha. Tuber dry
matter content was significantly higher with the application of 140-140-210 kg N-P2O5-
K2O/ha.
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
RESULTS AND DISCUSSION
Plant Height
Results revealed that there were no significant differences among the treatments
with regards to final plant height of as shown in Table 1. The height of the treatment plants
ranged from 83.15 to 83.90 centimeters.
Haulm weight
Table 2 shows that there were no significant differences in the haulm weight of the
treatment plants. However, plants applied with 210-140-140 kg N-P2O5-K2O/ha had
heavier haulms.
Table 1. Plant height
TREATMENT
MEAN
(kg N-P2O5-K2O/ha)
(cm)
210-140-140
83.50a
140-140-140
83.25a
140-140-210
83.90a
210-140-210
83.15a
140-140-140 +3 t/ha chicken dung
83.75a
Means followed by a common letter are not significantly different at 5% level (DMRT).
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Table 2. Haulm weight
TREATMENT
MEAN
(kg N-P2O5-K2O /ha)
(g)
210-140-140
417.49a
140-140-140
376.32a
140-140-210
386.27a
210-140-210
388.21a
140-140-140 +3 t/ha chicken dung
392.96a
Means followed by a common letter are not significantly different at 5% level (DMRT).
Days to Maturity
Plants applied with either 140-140-140 or 140-140-210 kg N-P2O5-K2O/ha
significantly matured earlier at 89 days as shown in Table 3.
Table 3. Days to maturity
TREATMENT
MEAN
(kg N-P2O5-K2O/ha)
210-140-140
90.50a
140-140-140
89.00b
140-140-210
89.00b
210-140-210
90.50a
140-140-140 +3 t/ha chicken dung
91.00a
Means followed by a common letter are not significantly different at 5% level (DMRT).
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Weight of Classified Tubers
In Table 4, there were no significant differences in the weight of marketable tubers
classified into sizes as affected by the fertilizers applied. However, application of 140-140-
210 kg N-P2O5-K2O/ha tended to increase the weight of bigger size tubers.
Table 4. Weight of tubers classified according to sizes
CLASSIFICATION
(kg/5 m2 plot)
TREATMEN
MARBL
SMAL
ME
BIG L
XL
SUPE
JUMB
T
E
L
D
R
O
(kg N-P2O5-
K2O/ha)
210-140-140
1.13a
1.54a
2.46a 0.93
1.27
1.43
1.06a
2.67a
140-140-140
1.20a
1.71a
2.09a a
a
a
1.26a
2.31a
140-140-210
0.85a
1.08a
2.53a 0.79
1.02
1.06
1.28a
2.76a
210-140-210
1.14a
1.53a
2.54a a
a
a
1.25a
2.26a
140-140-140
1.06a
1.58a
2.61a 1.05
0.98
1.28
0.96a
1.68a
+3 t/ha
chicken dung
a
a
a
1.19
1.18
0.72
a
a
a
1.22
1.54
1.28
a
a
a
Means followed by a common letter within a column are not significantly different at 5%
level (DMRT).
Legend: Marble = 37-43g, small= 44-50g, medium= 51-77g, big= 78-84g, large= 85-98g,
extra large= 99-105g, super= 106-125g, jumbo 126g-above
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Number of Classified Tubers
Table 5 shows that there were no significant differences in the number of
marketable tubers classified into sizes. However, greater number of extra large tubers was
obtained with the app1ication of 210-140-140 kg N-P2O5-K2O /ha, super tubers with 140-
140-210 kg N-P2O5-K2O/ha and jumbo tubers with 140-140-140 kg N-P2O5-K2O/ha.
Table 5. Number of tubers classified according to sizes
TREAT
CLASSIFICATION
MENT
(per 5 m2 plot)
(kg N-P2O5- Marble Small
M
B
L
XL
Super Jumbo
K2O/ ha)
210-140-140 45.50a
36.25a 38.75a
14.25a 14.50a 14.25a 9.50a
17.25a
140-140-140 47.00a
37.00a 35.00a
10.25a 12.00a 11.75a 12.00a 15.25a
140-140-210 33.25a
23.25a 39.25a
13.50a 10.75a 12.50a 12.75a 19.50a
210-140-210 46.25a
35.00a 40.24a
14.75a 13.25a 7.50a
11.50a 14.50a
140-140-140 45.50a
33.50a 41.25a
15.50a 17.50a 13.00a 8.00a
13.75a
+3 t/ha
chicken
dung
Means followed by a common letter within a column are not significantly different at 5%
level (DMRT).
Legend: Marble = 37-43g, small= 44-50g, medium= 51-77g, big= 78-84g, large= 85-98g,
extra large= 99-105g, super= 106-125g, jumbo 126g-above
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Tuber Yield
There were no significant differences in the marketable, non-marketable and total
yield as affected by rates of fertilizers applied as shown in Table 6. However, greater
marketable tubers were noted with the application of higher nitrogen and lower phosphorus
and potassium levels at 210-140-140 kg N-P2O5-K2O/ha.
Plants applied with 210-140-140 kg N-P2O5-K2O/ha had better haulm development
for photosynthesis, thus resulting to higher marketable tuber yield.
Computed Marketable Yield
There were no significant differences in the computed yield as shown in Table 7.
However, the highest computed marketable yield was obtained from plants applied with
210-140-140 kg N-P2O5-K2O/ ha at 24, 835.00 kg/ha.
Table 6. Tuber yield
TREATMENT
YIELD (kg/5 m2 plot)
(kg N-P2O5-
K2O/ha)
MARKETABLE
NON-
TOTAL
MARKETABLE
210-140-140
12.42a
0.48a
12.89a
140-140-140
11.49a
0.51a
12.00a
140-140-210
11.79a
0.47a
12.26a
210-140-210
11.88a
0.49a
12.28a
140-140-140 +3 t/ha 11.92a
0.59a
12.51a
chicken dung
Means followed by a common letter within a column are not significantly different at 5%
level (DMRT).
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Table 7. Computed marketable yield
TREATMENT
MEAN
(kg N-P2O5-K2O/ha)
(kg/ha)
210-140-140
24, 835.00a
140-140-140
22, 975.00a
140-140-210
23, 575.00a
210-140-210
23, 580.00a
140-140-140 +3 t/ha chicken dung
23, 845.00a
Means followed by a common letter are not significantly different at 5% level (DMRT).
Tuber Dry Matter Content
Table 8 shows that significantly higher dry matter content of tubers at 24.16% was
obtained with the application of lower nitrogen and phosphorus and higher amount of
potassium at 140-140-210 kg N-P2O5-K2O/ha. This dry matter meets the standard for
processing potatoes.
Dry matter content of potatoes for processing is of great importance. Dry matter
content of potatoes is acceptable when it is from 17.19% to 29.99% while the least
acceptable range is from 15.10% to 16.44% dry matter (Ludwig, 1985). HARRDEC (1996)
emphasized also that potatoes should have a dry matter of 21% for processing for best
quality.
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Table 8. Tuber dry matter content
TREATMENT
MEAN
(kg N-P2O5-K2O/ha)
(%)
210-140-140
22.32b
140-140-140
22.64b
140-140-210
24.16a
210-140-210
22.64b
140-140-140 +3 t/ha chicken dung
22.58b
Means followed by a common letter are not significantly different at 5% level (DMRT).
Soil Analysis
The composition of the soil in the experimental field prior to application of different
fertilizer rates is shown in table 9.
Table 9. Soil analysis
N, %
P, ppm
K, ppm
OM, %
pH
Initial
0.05
94
300
1.0
5.91
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Meteorological Data
The meteorological data during the study period is shown in Table 10. Rainfall
ranged from 0.72 mm to 3.40 mm; relative humidity, 83.63% - 87.00%; minimum
temperature, 10.7 oC - 15.50 oC; maximum temperature, 23.90 oC – 24.72 oC; and sunshine
duration, 267.16 min – 304.18 min.
Cost and Return Analysis
Table 11 shows that the highest return on investment at 62.78 % was obtained
with the application of 210-140-140 kg N-P2O5-K2O/ha followed by the application of
140-140-140 kg N-P2O5-K2O/ha.
Table 10.Meteorological data
Month
Rainfall
RH (%)
Temperature (0C)
Sunshine
(mm)
Min
Max
duration
(min)
November
0.72
87.00
15.50
24.72
267.16
December
0.72
86.90
14.48
24.66
227.71
January
1.40
83.63
13.10
24.15
296.95
February
3.40
86.60
10.70
23.9
304.18
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Table 11. Cost and return analysis
TREATMENT
ITEM
T1
T2
T3
T4
T5
Marketable
12.42
11.49
11.79
11.88
11.92
yield
kg/
5m2 plot
Inputs
Labor
20.50
20.50
20.50
20.50
20.50
Planting
66.67
66.67
66.67
66.67
66.67
materials
Fertilizers
17.86
15.50
17.86
20.21
27.50
Insecticides
25.67
25.67
25.67
25.67
25.67
Fungicides
37.50
37.50
37.50
37.50
37.50
Total
Expenses
168.20
165.84
168.20
170.55
178.04
Gross sales
273.80
256.22
245.10
252.58
228.95
Net income
105.6
90.38
76.90
82.03
49.09
ROI (%)
62.78
54.50
45.72
48.10
27.57
Rank
1
2
4
3
5
Legend (kg N-P2O5-K2O/ha): T1=210-140-140, T2=140-140-140, T3=140-140-210,
T4=210-140-210, T5=140-140-140 + 3 t/ha chicken dung
The Php selling price was: Marble= 2.00 per piece, and per kilogram: Small= 8.00,
Medium=10.00, Big=12.00, Large=15.00, Extra large=18.00, Super=20 and Jumbo=25
Pictorial Presentation
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Figure 1. Overview of the experiment field two weeks from planting
Figure 2. Tuber Yield
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
2a. Tubers classified according to sizes from plants applied
with 210-140-140 kg N-P2O5-K2O/ha
2b. Tubers classified according to sizes from plants applied
with 140-140-140 kg N-P2O5-K2O/ha
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
2c. Tubers classified according to sizes from plants applied
with 140-140-210 kg N-P2O5-K2O/ha
2d. Tubers classified according to sizes from plants applied
with 210-140-210 kg N-P2O5-K2O/ha
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
2e. Tubers classified according to sizes from plants applied with
140-140-140 kg N-P2O5-K2O/ha plus 3 t/ha chicken dung
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary
The study was conducted primarily to determine the effect of varying rates nitrogen
and potassium on the growth and yield performance of potato, establish the appropriate
level of nitrogen and potassium that will enhance growth, yield and tuber dry matter
accumulation and determine the economics of using different fertilizer rates in potato
production. It was conducted at the Horticulture Experiment Field, Benguet State
University, La Trinidad, Benguet from November 2011 to February 2012.
Growth in plant height and haulm weight did not significantly differ among
treatment plants and so with the number and weight of tubers classified according to sizes
including yield. However, marketable yield tended to increase at 24.83 t/ha with the
application of higher nitrogen rate at 210-140-140 kg N-P2O5-K2O/ha. Tuber dry matter at
24.16% was significantly higher with higher potassium level at 140-140-210 kg N-P2O5-
K2O/ha. The return on investment was highest at 62.78% with the application of 210-140-
140 kg N-P2O5-K2O/ha.
Conclusion
Based on the results, it is concluded that application of 210-140-140 kg N-P2O5-
K2O/ha could increase the marketable yield and correspondingly increase the return on
investment. Higher dry matter content of tubers could be obtained with the application of
140-140-210 kg N-P2O5-K2O/ha.
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
Recommendation
It is therefore recommended to apply 210-140-140 kg N-P2O5-K2O/ha on potato to
have a higher marketable yield and return on investment. For potato intended for
processing, application of 140-140-210 kg N-P2O5-K2O/ha could increase the tuber dry
matter content.
Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012
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Potato (Solanum tuberosum L.) Growth, Yield, and Tuber Dry Matter as Affected by
Nitrogen and Potassium Fertilizer Levels | GASIGAS, KIRBY D. APRIL 2012