Control of the Bakanae Disease of Rice by Soaking Seeds in Hot Water for the Hydroponically Raised Seedling Method in the Long-mat Type Rice Cultivation

Abstract

In the long-mat type hydroponic rice seedling method, rice seeds were soaked into hot water at 60°C or 62°C for 15 minutes to control the bakanae disease instead of using seed disinfectants. Germination rate of the hot-water soaked seeds was 6%-12% lower than the non soaked seeds, but the seedlings grew normally on the seedling beds and field. Using infected seeds, the number of bakanae plants on the seedling beds and field was reduced by the hot water treatment and did not differ significantly from a seed disinfectant treatment. These results suggest that soaking the seeds into hot water before sowing is effective against bakanae disease and could be used in the hydroponically raised seedling method.