Pyroxasulfone based tank-mix herbicide combinations for diverse weed flora control in wheat

Abstract

Field studies were conducted to assess the efficacy of pyroxasulfone alone and its combinations with other herbicides at different time of application against a diverse weed flora in wheat (Triticum aestivum L). Applications of pyroxasulfone at 125 g/ha as pre-emergence (PE) or early post-emergence (EPO) at 20 days after sowing effectively controlled the grass weeds (Phalaris minor Retz. and Avena ludoviciana Durieu). However, pyroxasulfone alone exhibited poor control of broad-leaved weeds, such as Medicago denticulata Willd and Rumex dentatus L. To address the limitations in controlling broad-leaved weeds, tank mix combinations of pyroxasulfone at 125 g/ha with either pendimethalin at 1000 g/ha or metsulfuron at 4 g/ha or metribuzin at 300 g/ha proved highly effective. Pre-emergence pyroxasulfone application in combination with either metsulfuron (125 + 4 g/ha) or with metribuzin (125 + 300 g/ha) in wheat gave effective control of diverse weed flora and improved wheat productivity by 52.1% and 51.2%, respectively, over untreated control. Ready mix combination of clodinafop + metribuzin 60 + 210 g/ha applied as post emergence (32 DAS) provided >99% control of P. minor, A. ludoviciana, M. denticulata and R. dentatus L., however the phytotoxicity with this treatment produced 6.7% lower yield as compared to season long weed free conditions. Among the herbicidal treatments, pre-emergence application of pyroxasulfone + metsulfuron at 125 + 4 g/ha had the highest net returns followed by alone application of pre-emergence metribuzin at 300 g/ha.