Crops and Pest Groups: Pyrazosulfuron ethyl 10% WP is a Herbicide used for the control of . weeds ( As given in leaflet table ) in Transplanted Rice crop.ispyribac-sodium inhibits the ALS enzyme which is vital for the synthesis of branched-chain amino acids in weeds. This disrupts protein synthesis and ultimately kills the weeds. Pyrazosulfuron-ethyl also disrupts ALS enzyme production, hindering amino acid synthesis and stopping weed growth.