[Technical Problem] To provide a method for controlling a rice disease exhibiting a high safety in rice plants, being conducted conveniently and efficiently with a reduced labor load and capable of exerting a sufficient effect.[Solution to Problem] By conducting at least one treatment selected from a dipping treatment, a dressing treatment, a coating treatment and a spraying treatment which is given to a pre-seeding rice seed using an agrochemical composition whose active ingredient is 3-(3,4-dichloroisothiazol-5-ylmethoxy)-1,2-benzothiazole-1,1-dioxide, the rice disease controlling effect can be sustained without affecting a rice plant adversely over a prolonged period from germination of the seed of said rice plant through cropping.本發明之課題係提供對稻之安全性高,並且簡便且有效率,勞動負擔少,可發揮充份效果之稻之病害防治方法。本發明之解決手段係藉由使用3-(3,4-二氯異噻唑-5-基甲氧基)-1,2-苯并噻唑-1,1-二氧化物作為有效成份之農藥組成物,對發芽前之稻種子,進行選自浸漬處理、粉衣處理、塗抹處理、噴霧處理之至少一種處理,使稻子不發生藥害,經過從該稻種子發芽至收穫之長期間,可以持續病害防治效果。
