Further evaluation of herbicides in yam (Dioscorea sp.)

Abstract

Two trials were carried out during 1986-87 at the Corozal substation to evaluate six herbicides for weed control in yam. In the first test, herbicides evaluated were ametryn, fluazifop-P, oxyfluorfen and paraquat. Ametryn at 4.48 kg ai/ha, in sequential application with fluazifop-P at 0.56 kg ai/ha, was highly effective against broadleaf weeds. Oxyfluorfen alone and oxyfluorfen + paraquat were also highly effective, but both treatments caused slight to moderate crop injury. In the second trial, ametryn, fluazifop-P, paraquat, cinmethylin and metolachor were evaluated. Ametryn at 4.48 kg ai/ha in sequential application with fluazifop at 0.84 kg ai/ha again proved to be highly effective. Cinmethylin alone was poor against broadleaf weeds. Its sequential application with paraquat slightly improved weed control. Metolachor at 3.54 and 7.08 L/ha+ paraquat also provided good weed control. Its sequential application with paraquat slightly improved weed control. Metolachor at 3.54 and 7.08 L/ha + paraquat also provided good weed control. In the first planting there were no significant differences in tuber yield between the weeded check and other herbicide treatments except for the fluazifop-P alone treatments. In the second planting, with the exception of the cinmethylin alone treatments and one of the cinmethylin + paraquat treatments, there were no significant yield differences between the weeded check and the herbicide treatments.