PHOSPHORUS USE EFFICIENCY, YIELD COMPONENTS AND YIELD OF COMMON BEAN (Phaseolus vulgaris L.) VARIETIES AS INFLUENCED BY RATES OFPHOSPHORUS AT YABELLO, SOUTHERNOROMIA

Abstract

Common bean is one of the economically most important legume crops grown in Ethiopia. However, the average yield reported at the national level is much lower than the potential yield. This is partly due to poor soil fertility management, limited use of improved varieties, inappropriate agronomic packages, and pest problems. Due to the limited availability of phosphorus in the soil of the study area, the yield of common beans was very low. Hence, this experiment was conducted to investigate the effect of phosphorus fertilizer rates on the growth, yield and yield components, to evaluate phosphorus use efficiency, and also to assess economic feasibility of common bean varieties in response to phosphorus fertilizer rate in Yabelo District, Southern Oromia, during the main crop season of 2023. The treatment studied consisted of five rates of phosphorus (0, 23, 46, 69, and 92 kg ha-1 ) and three common bean varieties (Hawasa dume, Ado, and Batu). The experiment was laid out in a factorial arrangement in a randomized complete block design (RCBD) with three replications. Data on Phenological, growth, yield, and yield-related parameters were collected and analysed using R software, version 4.2. The main effects of varieties and phosphorus fertilizer rates were significant (P< 0.001) on days to flowering, days to maturity, plant height, and the number of primary branches; however, harvest index was significant only by the main effect of phosphorus fertilizer rates. On the other hand, the interaction effect of the variety and phosphorus was also significant on total nodules number, effective nodules number, pod per plant, seed per pod, above-ground dry biomass yield, and seed yield. The highest seed yield (3077.10 kg ha-1 ) was recorded for the Hawasa dume variety at 46 kg P ha-1 . Correlation analysis also showed that seed yield was positively and significantly associated with most of the yield-related parameters. The grain, straw, and total phosphorus uptake, as well as the phosphorus use efficiency indices (recovery, agronomic, physiological, and utilization), were significantly affected by the interaction of varieties and phosphorus application rates. The highest net benefits (120856 ETB ha-1 ) with an acceptable marginal rate of returns (1144.44) were obtained from the Hawasa dume variety with 46 kg ha-1 of phosphorus.In conclusion, the Hawasa dume variety under 46 kg of Pha-1 is recommended for production in Yabello district, Southern Oromia. However, the experiment was conducted for one season at a single location. It is realistic to repeat similar experiments across wider ranges of agro ecology to give conclusive recommendations