Development of an Environment-friendly Disinfection Device for Rice Seed Using Steam Condensation Heat (Part 1)

—Selection of Treatment Condition and Its Control Effect—

Abstract

In order to increase efficiency and reduce the costs associated with chemical-free, environment-friendly disinfection methods for rice seed, we developed a device with the following purposes: to heat and pasteurize rice seed using steam condensation heat at high temperature during a short time, and to significantly simplify the cooling and drying process compared to the conventional hot water treatment. To select the optimal treatment conditions of the developed device, we focused on the measuring technique of grain temperature, which is used in grain drying engineering. The temperature of rice seed after heating was correlated with the seed germination rate under various heating conditions. We determined a temperature of 75±1°C as the optimal condition. This enables a control effect that is equally or more effective against rice seed-borne diseases than the conventional hot water treatment, without the negative effect of excess heat on seed germination.