Abstract:
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
