Relative time of planting of legumes (cowpea, soybean and groundnut) on weed suppression and yield in cassava cropping system

Weeds are a serious problem farmer’s face in tropical Africa, which significantly reduces yield. Field trials were conducted from September 2013 to September 2014 to determine the appropriate relative time of planting of legumes in cassava cropping system for optimum weed suppression. The experimental design was a randomized complete block design (RCBD) with three replicates. Treatments consisted of combinations of three relative times of planting for each of the three legumes (cowpea, soybean, and groundnut). One sole crop each of the legumes and cassava was added for comparison. The results indicated that early introduction of the legume (intercrop) into the cassava showed efficient weed control. The late introduction of the legume (intercrop) into the cassava decreased cassava yield whilst early introduction of the legume into the cassava increased cassava yield. Results from the study also revealed that the relative time of planting did not show any significant difference among the legume grain yield. However, late introduction of the cassava into the intercrop resulted in the highest grain yield. Key words: Weeds, cassava, legumes, cropping system, relative planting times.