Standardization of dose of sulfosulforun (MON 37503) in controlling weeds of rainfed wheat (Triticum aestivum) under mid-hill conditions of Himachal Pradesh

A field experiment was conducted during the winter (rabi) seasons of 1998–99 and 1999–2000 at Palampur, Himachal Pradesh, to find out the optimum dose of sulfosulfuron for controlling weeds in rainfed wheat (Triticum aestivum L. emend. Fiori & Paol.). Sulfosulfouron 30.0 g a.i./ha being at par with sulfosulfuron 30.0 g a.i./ha + surfactant and sulfosulfuron 37.5 g a.i./ha with and without surfactant resulted in significantly lower weed dry weight and higher yield attributes and yield of wheat when compared with the lower doses during both the years. However, during the first year diclofopmethyl 0.75 kg/ha being at par with isoproturon 1.0 kg ai/ha + surfactant resulted in significantly higher grain yield over other treatments, whereas during the second year dichlofop-methyl performed comparatively poor probably because of poor control of Phalaris minor Retz. which was the dominating weed this year. Isoproturon 1.0 kg/ha + surfactant was as effective as sulfosulfuron 37.5 g ai/ha + surfactant and hand-weeding twice during both the years and also with sulfosulfuron 37.5 g/ha without surfactant and sulfosulfuron 30.0 g ai/ha with and without surfactant during the second year of study.