摘要:
The present invention provides a hexahydropyridazine derivative of the formula (I): ##STR1## wherein R.sup.1 represents an alkynyloxy group, a cycloalkoxy group or an alkoxycarbonylalkylthio group, R.sup.2 represents an alkyl group, a phenyl group or a benzyl group, and X represents a halogen atom. This compound exhibits an excellent herbicidal effect on various weeds in treatment of field soil, foliage treatment and flooding treatment of paddy field, and has an excellent selectivity toward the weeds but not the crop.