COMPARATIVE ANALYSIS OF HERBICIDE BIOACTIVITY FOR WEED MANAGEMENT IN COWPEA CULTIVATION WITHIN LAPAI, NIGERIA

Abstract

Field study was carried out in 2022 and 2023 rainy seasons at the Teaching and Research Farm of Ibrahim Badamasi Babangida University, Lapai, Niger Stateto evaluate the efficacy of pre and post emergence herbicides against weed species on the performance of three varieties of cowpea (Vigna unguiculataL). The experiment consisted of three Cowpea varieties (Kananado (Local), SAMPEA11 [IT – 89-288] and SAMPEA12 [IT-89-391]) including six weed control methods (application of Paraquat at 1.5 kg a.i. ha^-1(Pre); Paraquat at 1.0 kg a.i. ha-1 (Pre) followed by (fb) Diuron at 1.5 kg a.i. ha-1(post); pendimethalin at 1.5 kg a.i. ha^-1 (pre) only; pendimethalin at 2.0 kg a.i. ha^-1 (pre) fb imazathapyr at 1.5 kg a.i. ha-1 (post); 2, 4-D at 2.0 kg a.i. ha^-1 fb Diuron at 1.5 kg a.i. ha^-1 (post) and Control. The experiment was laid out in a Randomize Complete Block Design (RCBD) replicated three times. Data that were collected include weedm(weed density and weed control efficiency), growth and yield parametersof cowpea and were subjected to analysis of variance (ANOVA) using statistical analysis software GENSTAT 17th Edition and Duncan's Multiple Range Test (DMRT) was used for mean separation at 5% level of probability. Results showed that SAMPEA11 had the highest number of leaves and leaf area. Weed species were suppressed more with SAMPEA 11 which also indicated that SAMPEA 11 recorded the highest weed control efficiency (WCE). Application of pendimethalin at 2.0 kg a.i. ha^-1 fb imazathapyr at 1.5 kg a.i ha^-1 recorded the tallest plant with highest number of leaves and branches of cowpea including the highest dry pod yield. From the result, SAMPEA 11 with application of pendimethalin at 2.0 kg a.i. ha^-1 followed by imazathapyr at 1.5 kg a.i. ha-1is therefore recommended for the production of Cowpea varieties in the study area.