一、前言稻条纹叶枯病是以灰飞虱为媒介的病毒病,老早已经明了在日本关东地方以西各地发生,而且除了冈山县试行的水稻套麦直播栽培之外,为害不那么大,并不认为是水稻的重要病害。可是,由于对二化螟虫有效药剂的出现,保温秧田的创设,以及适用品种的选育等,水稻的早期栽培已成为可能,而且,此种栽培方法具有水稻增产、避灾,减少稻瘟病发生,可高度利用水田等许多优点,所以已普遍推广,因而,条纹叶枯病迅速加重,至近年,因本病之故甚至造成水稻的早期、早植栽培不可能的地带。今后为了改进农业结构,必须建立高度利用水田、增产、省力的直播栽培方法等,即使变动水稻种 I. INTRODUCTION Rice stripe virus (SBP) is a virus disease caused by Laodelphax striatellus and has long been known to occur west of Kanto, Japan, and is not so damaging as it is except for the direct seeding cultivation of rice and wheat in Okayama prefecture , Do not think it is an important disease of rice. However, the early cultivation of rice has become possible due to the emergence of effective agents for stem borers, the establishment of heat-preserved seedlings and the breeding of suitable varieties. Moreover, early cultivation of rice has become possible. Moreover, this cultivation method has the effects of increasing rice yield, avoiding diseases and reducing rice blast , So paddy fields and other advantages can be highly utilized, so it has been widely popularized. Therefore, the stripe blight rapidly aggravated. In recent years, due to the disease, even the early and early planting of rice is impossible. In the future, in order to improve the agricultural structure, it is necessary to establish direct-seeded cultivation methods that make full use of paddy fields, increase yield and reduce labor costs,