Evaluation of sulfosulfuron and metribuzin for weed control in irrigated wheat (Triticum aestivum)

A field experiment was carried out on sandy clay-loam soil in North-western Himalayas of India and the experimental field had enough weed population. An average decrease in grain yield by 29% was observed due to season-long weed–crop competition. The best weed-control efficiency (85.7–93.8%) was achieved with metribuzin compared to other herbicides, i.e. Sulfosulfuron, isoproturon and 2, 4-D (55.4–87.5%). Earlier timing of metribuzin application (40 days stage) provided excellent control of Phalaris minor (Retz.) Pers., while control of Polygonum plebeium R. Br. and Melilotus indica All. was better with application at 60 days stage. Sulfosulfuron showed high activity against all weed species except P. plebeium and at equivalent doses, control was greater at the earlier timing of application. Slight crop injury in terms of yellowing of leaves and stunted growth was observed in the plots treated with sulfosulfuron. It was more pronounced under delayed application of the herbicide. The injury, however, disappeared with the advancement of crop growth. All the treatments except 2.4-D application gave significantly higher grain yield compared to weeded check. The highest grain yield was recorded in manual weeding treatment. Lower doses of sulfosulfuron (20 to 25 g/ha) and metribuzin (230 to 245 g/ha) both applied at 40 days stage gave yields similar to manual weeding treatment.