番木瓜环斑病流行时间动态分析

根据田间和室内试验结果，分析了番木瓜环斑病的季节流行动态、蚜虫田间消长规律以及显症和传染动态。在田间自然状态下，有翅蚜的迁入每年出现３个高峰（６月上旬、８月中旬和１０月中旬）。在蚜虫迁入后的１０～２０ｄ，病害的发展也相应出现高峰，病害的发展与蚜虫的迁入量以及温度、湿度、风速等的变化有关。比较３种数学模型对此病流行曲线、显症动态及传染动态的拟合效果，结果前者以Ｇｏｍｐｅｒｔｚ方程为最佳，后两者以Ｗｅ

TEMPORAL KYNAMICS OF PAPAYA RINGSPOT DISEASE

Epidemics of papaya ringspot disease (PRV)were monitored in fields in Guangzhou in 1988 and 1989.It was shown by analyzing the data of seasonal dynamics of disease develop-ment that the greatest rate of disease incidence increase appeared in early september.During the epidemic season, alate populations occurred in three peaks:early June,mid-August and mid-October.Ten to twenty days after each peak,there was a peak ofdisease incidence development.The seasonal dynamics of disease development and the growthand decline of the aphid populations were correlated to wind velocity,temperature and hu-midity.By comparing the fitness of three epidemic models (Logistic,Gompetz and Weibull)to the data of disease incidence,it was found that the disease development was best des-cribed by Gompertz model.With the equations of diseae progress,analyzing every parameterand calculating the number of days for disease to reach the incidence of 5%, 50%,90%,and99%,it was found that the disease epidemic pattern of papaya ringspotbelonged to the type of low virus source,low rate of infection and long epidemic pe-riod.By artificial inoculation with aphids(Myzus persicae),two models for infectiousand apparition dynamics of the disease were developped; both of them showed thatWeibull equation best described the dynamic of latent and incubation period,whichwere demonstrated to be about eleven and seventeen days respectively.