Weed persistence, crop resistance and phytotonic effects of herbicides in direct-seeded rice

Results of experiment conducted during Kharif season of 2010 and 2011 with ten different herbicides and combinations on yield of direct seeded rice revealed that crop resistance index and agronomic management index were maximum in hand weeding treatment followed by fenoxaprop + (chororimuron + metsulfuron) and cyhalofop butyl +(chlorimuron + metsulfuron). Weed persistence index was also maximum in Hand weeding treatment followed by cyhalofopbutyl and pyrazosulfuron. Hand weeding treatment has maximum phytotonic effect followed by fenoxaprop + (chororimuron + metsulfuron) and cyhalofop butyl + (chlorimuron + metsulfuron). Fenoxaprop + (chororimuron + metsulfuron) and cyhalofop butyl + (chlorimuron + metsulfuron) were best herbicides for direct seeded rice from economics and environmental point of view. Fenoxaprop + (chororimuron + metsulfuron) and cyhalofop butyl + (chlorimuron + metsulfuron) have recorded lower persistence of escaped weeds indicating broad spectrum effect in controlling the weeds