Response of pepper (Capsicum annuum L.) to preemergence application of Oxadiargyl and pendimethalin

Two field experiments were conducted in two agro-ecological zones of Ghana (Forest and Coastal Savannah) to assess the efficacy of preemergence herbicides Oxadiargyl and Pendimethalin on weed incidence, growth and yield of pepper. The experiment was factorial arranged in a randomized complete block design. The treatments were Oxadiargyl at 0.4, 0.5, 0.6 L/ha, Pendimethalin at 1.5, 2.0, 2.5 L/ha and hand weeding at intervals of 3, 6 and 9 weeks as control. Data was collected on weed type and abundance, number of days to weed emergence, type of re-emerging weeds and percentage weed cover. Data on plant height, number of branches per plant, yield and yield components of pepper plants were also collected. Results indicated that application of Pendimethalin led to a significantly (p < 0.05) longer number of days to weed emergence as compared to the application of Oxadiargyl which also delayed weed emergence significantly longer than hand weeding. Plant height was not affected by weed control method. The yield of pepper plants was significantly higher in plots where Pendime-thalin (2.0 L/ha) was applied. Generally, the yield components of pepper plants have been positively affected by weed control treatments. However, application of Pendimethalin at 2.0 L/ha resulted in better weed control.