Response of common bean (Phaseolus vulgaris L.) varieties to rates of blended NPS fertilizer in Adola district, Southern Ethiopia

Abstract

Common bean is one of the most economically important pulse crops cultivated in Ethiopia. However, its average yield reported at national level remains far below the potential yield to be attained. This is partly due to low soil fertility management, inappropriate agronomic packages and diseases and pest problems. Hence, this experiment was conducted to investigate the effect of blended NPS rates on growth, yield and yield components of common bean varieties and to identify economically feasible rates of blended NPS at Guji Zone Southern Ethiopia. The experiment was conducted in Adola sub-site of Bore Agricultural Research Center during 2016 to 2017 main cropping seasons. The factors studied were six rates of blended NPS (0, 50, 100, 150, 200 and 250 kg ha-1) and three varieties of common bean (Angar, Ibado and Nasir). These were laid out in a factorial arrangement in randomized complete block design with three replications. Data on phonological, growth yield and yield related parameters were collected and analyzed using SAS software. The result showed that significantly the highest number of primary branches per plant (2.77) and the highest number of total pods (18.52) were recorded at the highest rate of 250 kg NPS ha-1 whereas the highest number of total nodules (80.47) and effective nodules per plant (35.54) were obtained from the application of 200 kg NPS ha-1. Among the varieties, Angar gave significantly the highest number of primary branches per plant (2.55) and number of pods per plant (15.3). The interaction of variety and blended NPS had significant effect on almost all parameters except on the number of total and effective nodules per plant, number of primary branches per plant and number of pods per plant. Variety Nasir gave the highest plant height (99.72 cm) with application of 150 kg NPS ha-1 while Ibado with application rate of 200 kg blended NPS ha-1 had the highest hundred seed weight (54.33 g). The highest grain yield (3260 kg ha-1) was recorded for variety Angar at 250 kg NPS ha-1. However, the highest net benefit (29,825 Birr ha-1) was obtained from combination of variety Ibado with application 200 kg ha-1 of blended NPS. Thus, it can be concluded that combined application of 200 kg ha-1 of blended NPS with variety Ibado proved to be superior with respect to economic advantage.   Key words: Blended fertilizer, nitrogen, phosphorus, sulphur.