Abstract
In 1978, a virus-like desease of rice, which has been unknown in Japan, occurred in Fukuoka and Kagoshima Pref. The symptoms in rice cv. Taichung Native 1 showed stunting with yellowing, excessive tillering and an erect growth habit. The desease was transmitted by brown planthopper (Nilaparvata lugens Stål) in the persistent manner. The incubation period in insect was 8-17 (av. 12) days. The proportion of insect that transmitted the causal agent was about 32%. From the characteristics of symptoms and the mode of insect transmission, this disease was identified as the rice grassy stunt disease.
