Bio-efficacy of sulfonylurea herbicides in controlling weeds of wheat.

Abstract

Experiment con.ducted during the rabi season of.1997-98, on weed management of wheat at the Instructional Farm (22.93°N, 88.53°E) of Bidhan Chandra Krishi Viswavidyalaya, West Bengal clearly indicated that hand weeding twice showed the best performance in giving the maximm grain yiels as compared to herbicide treated plots due to the fact that ·the treatment kept the weed population under control during acdve tillering stage. Among the herbicidal treatments, combination of Metsulfuron methyl+ 2, 4-D Na Salt@ (0.004+0.500) kg a. i. ha was the best in reducing the weed population and weed dry weight without showing and phytotoxicity to the crop. This herbicidal treatment, thou gh record the highest grain yield, it did not differ significantly with the hand weeding treatme nt, - 1 Metsu]furon methyl+ 2, 4-0 Na Salt@ (0.004+0.2 50) kg a.i. ha 2, 4-D Na Salt @0.500 kg a.i. ha-1, Metsulfuron methyl +2, 4-D Na Salt @ (0 .002+0 .25 0) kg a.i. -1 -1 ha + 0.2% surfactant and Metsulfur·on methyl@ 0.004 kg a.i. ha . Among the herbicidal" treatments, Metsulfuron methyl@. 0.002 kg a,. i. ha-•+ 0.2% surfactant recorded the lowest grain yield.