Abstract
In order to raise efficiency and to reduce the costs associated with chemical-free, environment-friendly disinfection methods for rice seed, we propose a rice seed disinfection method that uses steam heating. This method aims to sterilize the surface of rice seeds with wet heat using steam condensation, and to simplify the cooling and drying process compared with the conventional hot water treatment.
To investigate the applicability of this method and determine the optimal conditions for rice seed disinfection, we examined the effects of heating air temperature, air humidity, air flow rate, and heating time on the sterilization rate and germination rate of rice seeds. We found that the optimal conditions were as follows : heating with an air temperature of 200°C, and wet bulb temperature of 80°C, a heating time of 2s, an air flow rate of 1.8m/s, and cooling by ventilation with ambient air for more than 60 s. Using these optimal conditions, the newly described disinfection method was as effective against blast and bacterial grain rot as the conventional hot water treatment.
