CHEMICAL WEED-CONTROL IN IRRIGATED SWEET-PEPPER (CAPSICUM-ANNUUM-L)

Field trials were conducted at Kadawa in the 1983/4 and 1984/5 dry seasons to evaluate some herbicide treatments for weed control in transplanted irrigated sweet pepper (Capsicum annum L., var. California mild). In the 1983/4 dry season, mixtures of metolachlor with metribuzin at 1.5 + 0.25 and pendimethalin plus linuron at 1.5 + 0.75 kg a.i./ha, each followed by supplementary hoe-weeded control. Without supplementary hoe-weeding, mixtures of linuron with oxadiazon and alachlor each at 0.75 + 1.5 kg a.i./ha and metolachlor plus metobromuron at 1.25 + 1.25 kg a.i./ha resulted in yields comparable to the hoe-weeded control. In the 1984/5 dry season, linuron at 0.75 kg a.i./ha in mixture with either diphenamid, metolachlor, oxadiazon or chlorthal dimethyl ester at 3.0, 1.5, 1.5 and 10.0 kg a.i./ha, respectively, as well as metolachlor plus metobromuron at 1.5 + 1.5 kg a.i./ha, all supplemented with one hoe-weeding, combined effective weed control with high pepper fruit yield comparable to the hoe-weeded control. In this study unchecked weed growth throughout the crop life cycle resulted in 90% and 97% losses in sweet pepper fruit yield compared with the approximate maximum obtained in the 1983/4 and 1984/5 dry seasons, respectively.