Elefect of the Pre-Emergence Herbicide Metolachlor on the Growth and Yield of Blacktgram (Vigna mungo L.)

Abstract

During th e1986 and 1987 wet seasons, an investigation was made of the efficacy of the pre-emergence herbicide metolachlor in blackgram, when broadcast sown at different seeding rates under rainfed conditions. The metolachlor was used at a rate of 0.75 kg a.i./ha and the seeding rate ranged from 6 to 56 kg/ha. Only in teh second year was there a statisticaly significant increase in yield as a result of the use of metholachlor, there being a 18 percent increase in grain yield in the herbicide treatment. Seeding rate had a significant affect on yield in both the herbicide and non-herbicide treatments, with no apparent interaction between seeding rate and herbicide treatments in terms of final grain yield in either year of experimentation. Small but non-statistically significant differences in the plat parameters of plant height, branch and pod number per plant, were recorded between the hervicide treatments. However, seeding rate did hve a significant affect on these plant parameters.