Effects of NPSB and Urea Fertilizer on Onion Yield in Ethiopia

BAHIR DAR UNIVERSITY COLLEGE OF AGRICUTLURE AND ENVIRONMENTAL SCIENCES GRADUATE PROGRAM EFFECTS DIFFERENT RATES OF NPSB AND UREA FERTILIZER ON YIELD AND YIELD COMPONENTEOF ONION (Allium cepa L.) AT KOBO DISTRICT OF AMHARA REGION, ETHIOPIA M.Sc. Thesis By: AndargeAsmare Kassaw Department of Plant Sciences (MSc. Program in Horticulture) Major Advisor: Melkamu Alemayehu (PhD) Co-Advisor: Biruk Masrie (PhD) January 2018 Bahir Dar, Ethiopia

1.Introduction 2. Material and Methods 3. Result and Discussion 4. Conclusion and Recommendation

1.1. Background and Justification Bulb crops, like garlic, onion, shallot and leek, contribute significant nutritional values to the human diet and have medicinal properties They are primarily consumed for their ability to enhance the flavor of foods (Randel, 2000) Onion can be harvested and sold either green to be used in salads (Lannoy, 2001) Mature bulbs are cooked or eaten raw as a vegetable (Emmett and Straub, 1992)

Onions are also highly beneficial in human nutrition and provide a rich source of Vitamins B1, C and E and trace elements The carbohydrate content of onion ranges from 5% to about 11% and 100 g edible portion provides about 36 kcal energy value (Malik, 2000) Ethiopia has enormous potential to cultivate vegetables including onion on small as well as commercial scale

onion is widely produced by small holder farmers and some commercial growers throughout the year for local use and export market The crop is produced both under rain fed conditions in the meher season and under irrigation in the off season The area under onion production is increasing from time to time due to expansion of small scale irrigation areas in the country Onion is also one of the most widely produced and highly commercialized vegetable crops in Kobo district

The reasons for low productivity of onion in Ethiopia in general and in Kobo district in particular is among others low soil fertility, application of inappropriate fertilizer practices, high incidence of diseases and insect pests (Lemma Desalegn and Tekalign Tsegaw et al., 2012) Sirinka Agricultural Research Center (SARC) in this regard, recommended the use of about 64 kg N ha-1 and 46 kg P2O5ha-1fertilizers for onion production in the area (SARC, 2008) The majority of the farmers in kobo district however used inappropriate rates of nitrogen and phosphorus fertilizers rates, poor management Shimelis Aklilu,2003;

1.3. Objectives of the Study The general objective of the study was to improve the production and productivity of onion by identifying appropriate application rates of NPSB and urea fertilizers at Kobo District ofAmhara Region

The specific objectives To evaluate the effects of different rates of NPSB and urea fertilizer on growth, yield and yield components of onion To determine the economical optimum rates of NPSB and urea fertilizer for the production of onion in the study area

2.1 Description of the StudyArea The experiment was conducted at Sirinka Agricultural Research Center, Kobo sub-center research field in 2017 during the offseason under irrigation (Figure 3.1) The research Center, Kobo sub-center research field is located in Amhara National Regional State, North Wollo Zone, Kobo district which is 571 km north-east of Addis Ababa with an altitude of 1500 meters above sea level The area has mean annual rainfall of 668 mm with a maximum and minimum temperature of 310C and 150C, respectively (SARC, 2008)

2.2 Experimental Materials, Treatments and Design The onion variety namely Bombay red was used for this study Bombay red is an exotic variety that requires about 110 days for maturity after transplanting (MoARD, 2009). The variety is well adapted to areas with altitude of 700-2000 meter above sea `level NPSB fertilizer which contains N:P2O5:S:B at the concentration of 19%, 38%, 7% and 0.1% respectively urea (46% N) fertilizer were used for this study

The treatments consisted of four rates of urea fertilizer (0, 50,100,150 kg ha-1) and four rates of NPSB fertilizer (0, 50, 100, 150, kg ha-1) The experiment was laid down in (RCBD) with 4 x 4 factorial arrangements and replicated three times Seedlings were planted on a plot size of 2 m x 2 m in double row planting system The gross and net plot areas were 4 m2and 3.42 m2, respectively The distances between adjacent plots and blocks were 0.5 m and 1m, respectively

2.3. Data Collection andAnalysis The growth and yield parameters of onion were collected from the central three double rows with net plot area PH, LN, AGB, ,DWAGBM, BW, BL and BD, Were taken as experimental parameters of the study by standard measurements The collected data were subjected to analysis of variance (ANOVA) using SAS (Statistical Analysis System) version 9.0 (SAS, 2004). Mean separations were carried out using Fisher s Protected Least Significant Difference (LSD) at 5% or 1% significance levels based on theANOVA results

2.4 Economic Analysis Gross income and net benefit of each treatment were calculated Each pair of treatments, marginal rate of return (MRR) was calculated The treatment which was non-dominated and having a MRR of greater or equal to 50% with the highest net benefit was taken to be economically profitable

3.1. Growth Parameters of Onion PH, (P<0.001) affected by the application urea fertilizer in the main effect PH, LN, SFW,& SDW were highly Significantly (P<0.001)affected by the application NPSB fertilizer in the main effect In the interaction effect SFW,SDW, MY& TBY were very highly Significantly (P<0.001) affected by the application urea & NPSB fertilizer SFW & SDW,were highly Significantly

In the interaction effect BW was highly Significantly (P<0.01) affected by the application urea & NPSB fertilizer The interaction effect of urea and NPSB have not influenced the plant height of onion Application of NPSB fertilizer at the rate of 150 kg ha- 1 recorded the highest plant height of onion (40.94 cm) urea fertilizer at the rate of 150 kg ha-1recorded the highest plant height of onion (39.41 cm) The main effect of urea and its interaction with NPSB has not influenced number of leaves per plant of onion

The maximum number of leaves (8.34) was record at the application of 150 kg ha-1NPSB fertilizer. Control plants without NPSB fertilizer recorded the minimum number of leaves per plant (6.10) In the interaction effect of urea and NPSB fertilizer rates the highest above ground shoot fresh weight per plant (12.98g) was recorded at the combination of 150 kg ha-1urea and 150 kg ha-1NPSB ha 1

Table 4.1. Main effects of urea and NPSB fertilizers on growth parameters of onion UREA NPSB Plant (kg ha- Plant Leaf number (kg ha-1) height(cm) 1) height(cm) 0 36.79b 0 35.67c 6.10c 50 37.10b 50 36.87c 6.64c 100 38.81a 100 38.62b 7.28b 150 39.41a 150 40.94a 8.34a Sign. Level ** ** ** CV (%) 3.89 3.89 10.64 SE 1.4 1.44 0.57

In the interaction effect the highest dry weights of above ground biomass of onion plant were recorded in treatment 16(1.49g) where 150 kg urea and 150 kg NPSB ha-1 was applied Urea fertilization significantly (P < 0.001) extended the number of days required for the onion crop to attain physiological maturity NPSB fertilization and its interaction with urea did not affect the physiological maturity of the onion plants

Table 4.2. Interaction effect of urea and NPSB fertilizers on growth parameters of onion Urea (kg ha1) NPSB (kg ha-1) Shoot fresh weight (g) Shoot dry weigh 0 50 100 150 0 50 100 150 0 50 100 150 0 50 100 150 5.25i 5.52i 6.63h 6.77h 7.26g 7.32g 7.78f 7.88 8.02f 8.77e 9.00e 9.65d 10.59c 11.00c 11.94b 12.98a 0.48m 0.51m 0.64l 0.69k 0.78j 0.82ij 0.85i 0.89h 0.91gh 0.94fg 0.96ef 0.98de 1.00cd 1.03c 1.30b 1.49a 0 50 100 150 Sign. deference CV (%) SE *** 2.29 0.25 *** 2.27 0.02

3.2. Yield and Yield Components of Onion as Affected by Different Rate of Urea and NPSB Fertilizer MY and TBY were highly Significantly (P<0.001) affected by the application urea fertilizer in the main effect BL, BD, MY, and TBY were highly Significantly (P<0.001) affected by the application NPSB fertilizer in the main effect Bw was significantly (P< 0.01) affected by the application urea fertilizer in the main effect

Significantly maximum bulb weight (45.75 g) was obtained in 50 kg ha-1 urea and 150 kg ha-1 NPSB rates were applied. The minimum onion bulb weight (19.03g) was recorded in control plots without urea and NPSB fertilizer The main effect of urea and its interaction effect with NPSB however were not influenced the onion bulb diameters Maximum bulb diameter (4.24 cm) was obtained by application of 150 kg ha 1 NPSB fertilizer The lowest bulb diameter was obtained on onion plants on control plants without NPSB fertilizer

The main effect of urea and its interaction effect with NPSB were not significantly influenced the bulb length of onion maximum bulb length (4.19 cm) was obtained by application of 150 kg ha 1 NPSB fertilizer The minimum onion bulb length (3.26 cm) was recorded in control plants without NPSB fertilizer The marketable yield of onion generally increased with increasing rates of urea and NPSB. The highest marketable yield of onion (26.36 t ha 1) was recorded at the combined application of 150 kg ha 1urea and 150 kg ha 1 NPSB. The lowest marketable yield (11.48 t ha 1) was recorded at control treatments

The unmarketable bulb yield of onion was very highly significantly influenced by the main effect of NPSB fertilizer. The main effect of urea and its interaction effect with NPSB fertilizer however were not significant on unmarketable bulb yield of onion The highest unmarketable bulb yield (0.76 t ha-1) of onion was recorded on control plants without any type fertilizers Total bulb yield of onion generally increased with increasing rates of urea and NPSB fertilizer. The highest total bulb yield of onion (26.64 t ha-1 ) was recorded by combined application of 150 kg ha 1 urea and 150 kg ha 1 NPSB fertilizers

Table 4.4.Main effects NPSB fertilizers on yield and yield components of onion NPSB (kg ha-1) Unmarketable Bulb length Bulb diameter yield (t ha-1) 0.76a 0.67b 0.56c 0.41d *** 17.00 0.1 (cm) 3.26d 3.55c 3.83b 4.19a *** 7.41 0.27 (cm) 3.44c 3.84b 4.06a 4.24a *** 6.11 0.23 0 50 100 150 Significant level CV (%) SE

Table 4.5: Interaction effects of urea and NPSB fertilizers on yield and yield components of onion Urea (kg ha1) NPSB (kg ha-1) Bulb weight (g) Marketable yield (t ha-1) 11.48j 13.40i 14.05hi 17.92c 14.19ghi 15.22efg 16.23de 16.92cd 13.29i 15.11fgh 16.15def 23.23b 11.74j 15.02gh 17.82c 26.36a *** Total bulb yield (t ha-1) 0 19.03g 33.33de 33.33de 45.25a 24.79f 26.41f 37.55cd 45.75a 24.79f 34.32de 35.48cde 43.45ab 26.29f 33.13e 39.29bc 45.27a ** 12.32j 14.17i 14.65hi 18.31c 14.89ghi 15.83efg 16.77de 17.37cd 14.02i 15.64fgh 18.33c 23.23b. 12.53j 15.64fgh 18.33c 26.64a 50 100 150 0 50 100 150 0 50 100 150 0 50 100 150 0 50 100 150 Significant level *** CV (%) SE 7.66 2.26 4.15 3.98 0.67 0.67

3.3. Economic Analyses The economic analysis was done according to CIMMYT (1988) to calculate the incomes and expenses of each treatment used in the experiment To calculate the gross incomes, the marketable yields obtained from each treatment of onion plants were downscaled by 10%

The highest net benefit (210168.00-Eth-Birr) was recorded by combined application of 150 kg ha-1 urea and 150 kg ha-1 NPSB fertilizers To calculate marginal rate of return, the dominance analysis was carried out by listing the treatments in order of increasing the total variable costs The highest marginal return was application 150 kg ha-1 urea and 150 kg ha-1 NPSB fertilizers with the value of 7205.17(%)

4.1 Conclusions The application of urea and NPSB fertilizers influenced the growth, yield and yield components of onion Significantly maximum marketable bulb yield (26.36 t ha -1) of onion was obtained by combined application of 150 kg ha-1 NPSB and 150 kg ha-1 urea The highest marginal rate of return (MRR) was recorded application of 150 kg ha-1 NPSB and 150 kg ha-1 urea fertilizer with the value of 7205.17%.

4.2 Recommendation Based on the results combined application of 150 kg ha-1 NPSB and 150 kg ha-1 urea gave the highest net benefit of onion in Kobo district Combined application of -150- kg ha-1 NPSB and 150 kg ha-1 urea gave the highest marginal rate of return which can be recommended for economical and profitable production of onion in Kobo district However, as the results are limited to one season and location, further study should be done over more seasons and locations

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