Effect of Legume Intercropping on Infestation of Striga hermonthica and Productivity of Sorghum at Babile District, Oromia Reginal State, Ethiopia

Sorghum is the most widely cultivated crop in eastern part of Ethiopia including Babile district. However, in this district the productivity of the crop is highly influenced by biotic and abiotic factors. Striga hermonthica is one of the major biotic factors in reducing the grain yield of the crop. In 2019 and 2020, field experiments were conducted to assess the influence of legume intercropping on severity of the weed and evaluate its effect on productivity of the component crops. During the experimentation, randomized complete block design with three replications in a factorial combination was used as an experimental design. ANOVA result showed the presence of the highest number of Striga plants (19 plants/plot) which were recorded from the untreated plots. The lowest numbers of Striga plants (6 plants/plot) were recorded from intercropped plots indicating the presence of the lowest infestation value of the weed. The analysis of the results also indicated that the highest Sorghum grain yield of (3 t/ha) and the maximum 2262% marginal rate of returns were obtained from Sorghum cowpea intercropped simultaneously compared to the control plots (1.9 t/ha). This study revealed that from the intercropped system, a yield increment of 36.7% was obtained as compared to the solely planted Sorghum. Analysis of the LER (land equivalent ratio) of the system also showed that in both cropping seasons, legumes intercropped with Sorghum resulted in a higher mean values of LER in all, intercropping types and row arrangements of individual land equivalent ratio and the mean for common bean (2.1), cowpea (2.5), and soybean (1.89) have the highest individual land equivalent ratio values indicating the productivity of the system. Thus, from this study it is concluded that intercropping Sorghum with legume crops lowered the level of Striga infestation and increased grain yield of the crop. Hence, this practice can be adopted to overcome the negative impact of this parasitic weed in Sorghum fields.