RESPONSE OF COMMON BEAN (Phaseolus vulgaris L.) VARIETIES TO RATE OF BLENDED NPS FERTILIZER IN JARSO DISTRICT, EAST HARARGHE

Abstract

Common bean (Phaseolus vulgaris L.) is highly preferred by Ethiopian farmers because of its fast maturing characteristics that enable households to get cash income required to purchase food and household needs when other crops have not yet matured. However, the current national average yield of common bean is far less than the attainable yield under good management conditions for most improved varieties. This low yield of common bean in Ethiopia is attributed to several production constraints. Thus, a field experiment was conducted to assess the effect of blended NPS rates on growth, yield and yield related traits common bean varieties and to estimate economically feasible rates of blended NPS fertilizer for common bean production. The experiment was conducted in Jarso district sub-site of Melka jebdu demonstration site during 2019 to 2020 main cropping seasons. Treatments consisted of factorial combinations of three common bean varieties (Babile, Fedis, and Tinike,) with five NPS fertilizer rates (0, 50, 100, 150 and 200 kg ha-1) laid out in randomized complete block design with three replications. The highest days to 50% flowering (48.73 days), days to 90% physiological maturity (95.8 days), effective nodule number (33.67), number of seed per pod (4.67) were recorded from variety Tinike while the highest total nodule number (69) , number of primary branch per plant (3.53), stand count (96.53) and hundred seed weight (45.38 g) were recorded from variety Fedis. The highest level of NPS rate (200 kg ha-1) resulted in higher values of number of primary branches per plant, number of total nodules, number of effective nodules, number of seeds per pod and 100 seed weight. However, the highest number of pod per plant (25.33), Grain Yield (2565 kg ha-1 and harvest index (41,30) , were recorded due to application of 150 kg ha-1 of blended NPS for variety Fedis. Variety Tinike gave the highest plant height (67.60 cm) and above ground dry biomass (6330kg ha-1) with application of 200 kg NPS ha-1. Agronomic Efficiency (kg seed kg-1 of NPS) as ratio of seed yield to NPS fertilizer rates with three common bean varieties showed highly significant (p<0.001) effects with the highest value (5.6 kg seed kg-1 of NPS) in treatment combination of 150 kg NPS ha-1 fertilizer. Based on this result, the highest net benefit of 53,454 ETBha-1 with M a r g i n a l R a t e o f R e t u r n of 8 5 0 . 5 % was obtained from the treatment combination of 150 kg NPS ha-1application rate with Fedis variety. Thus, it can be concluded from the result of present study that the use of variety Fedis with application of 150 kg NPS ha-1 could be recommended to enhance the productivity of common bean in the study area. However, the result of the present study need to be validated and proved in the same agro-ecologies and seasons with further experiments in order to give a blanket recommendation for wide range of common bean production