Interaction Effect of Common Bean Intercropping with NPS Blended Fertilizer on Striga hermontica severity reduction and Productivity of Sourghum at Fedis, Eastern Ethiopia

Abstract In Ethiopia, sorghum is the main crop grown for food and feed. But in the majority of eastern Ethiopia's sorghum-growing regions, Striga hermonthica is the main obstacle. In Fedis District, an experiment was carried out to assess the interaction effect of blended NPS fertilizer and common bean planting density for Striga management over the two main cropping seasons of 2019 and 2020. The treatment combination consisted of four NPS blended fertilizer levels (0, 50, 100, and 150 kg ha-1 NPS) in a factorial arrangement in a randomized complete block design with three replications, susceptible sorghum variety (Teshale) and common bean variety (Dursitu), planting densities of (25%, 50%, and 75%). The analysis of variance results indicated that treatment interactions on Striga infestation caused highly significant (p < 0.001) changes. The combination of 50% common bean planted density and 100 kg ha-1 NPS blended fertilizer application gave the lowest Striga count (2 Striga shoots) per plot, whereas the single planted susceptible sorghum variety (Teshale) produced the highest Striga count (8 Striga shoots) per plot. The main findings of this study consequently indicate that the host crop (sorghum) was supported by a 60% reduction in Striga hermonthica infestation when NPS fertilizer and common bean planted density were combined. The combination of 50% common bean planted density and 100 kg NPS ha-1 blended fertilizer application produced the maximum (2.54 t ha-1) grain yield of sorghum, while the control plot produced the lowest (0.98 t ha-1) grain yield. Hence, farmers in the study area could manage Striga and improve sorghum productivity through the combination of common bean with NPS blended fertilizer under natural Striga infestation.