preemergence herbicide苗前处理除草剂
preemergence tillage出苗前耕作
preemergence control未出苗前除草
preemergence management苗前养护
preemergence herbicides出土前除草剂
preemergence spray出苗前喷药
preemergence application出土前施用
preemergence treatment苗前处理
preemergence herbicide screening芽前除草剂