Application of a rice blast control agent containing an isothiazolecarboxylic acid derivative of the below-described formula, which shows excellent activity against rice blast (Pyricularia oryzae) in rice cultivation, to the water surface of a paddy rice field results in the absorption of the derivative through roots of rice plants, so that the resistance of the rice plants can be enhanced. ##STR1## wherein R.sup.1 and R.sup.2 independently mean a hydrogen or halogen atom or a particular group, and Y stands for an OR.sub.3 group (R.sup.3 being a hydrogen or alkali metal atom or a particular group), an NHR.sup.4 group (R.sup.4 being a hydrogen atom or a particular group), or a morpholino group.
将含有以下描述的公式的异
硫唑
羧酸衍
生物的
水稻稻瘟控制剂应用于稻田
水面,对
水稻种植中的稻瘟(
水稻纹枯病菌)表现出优异活性,导致衍
生物被
水稻植株的根吸收,从而增强
水稻植株的抗性。其中R.sup.1和R.sup.2分别表示氢原子或卤素原子或特定基团,Y代表OR.sub.3基团(R.sup.3为氢原子或碱
金属原子或特定基团),NHR.sup.4基团(R.sup.4为氢原子或特定基团)或
吗啡基团。