水稻矮缩病的研究——Ⅱ.病害感染、发生和防治

水稻矮缩病的潜育期因气温、水稻生育期、介体黑尾叶蝉(Nephotettix cincticeps)的虫龄、性别等不同而异,一般为10～15天。水稻在分蘖初期到盛期最易感病,这些病株均不能抽穗结实;分蘖末期感染者,产量损失达80%以上。病毒在虫体内越冬,越冬代带毒成虫传毒给早稻,第2、3代带毒虫传毒给晚稻。第1、4代经卵带毒虫,还能分别引起早、晚稻再次侵染。以早栽双季晚稻和杂交晚稻发病最重,其主要感染期是在本田初期。以农业防治为基础,治虫防病抓适期的综合防治措施,能有效地控制病害流行。病区在连片种植的基础上,对早栽双季晚稻本田初期喷药治虫1～3次,能收到显著的防病效果。

STUDIES ON RICE DWARF VIRUS DISEASE II. INFECTION,DISEASE DEVELOPMENT AND CONTROL

The incubation period of rice dwarf virus in plant ranges from 10-15 days varying with temperatures, rice growth stages and the instars and sex of the insect vector Nephotettix cincticeps. The most susceptible stages of rice is from the first tillering to full tillering stage. The infection at these stages results in no panicle or grain, while at the end of tillering stage the yield losses of about 80% of the rice. The virus overwinters in the insect vector. It is transmitted to the first crop of rice by the viruliferous adult insects of the overwintering generation, and to the second crop of rice by the viruliferous insects of 2nd and 3rd generations. The transovarial virus in 1st and 4th generations of congenital viruliferous insects can cause the second infection on early and late rice respectively. The disease is usually much more severe on the earlier transplanted late rice, especially on the late hybrid rice. The infection occurs mainly at the initial period after transplanting. The disease can be effectively controlled by adopting the integrated control measures on the basis of the cultural practices and timely elimination of the vectors. In the disease-prone areas, the effective control of the disease can be attained by the application of insecticide for 1~3 times at the initial period of the earlier transplanted late rice for eliminate the insect vectors to be based on the crop with the same growth duration are suggested for planting in adjacent fields.