甜叶菊黑斑病发生动态及药剂防治研究

A study on development dynamics of Stevia black blotch and its control with fungicide

于田间甜叶菊生长发育时期，系统调查黑斑病发病率及病情指数。结果表明：甜叶菊黑斑病田间发生动态呈“S”型生长曲型，符合逻辑斯蒂模型，病情发展出现两个高峰。甜叶菊黑斑病发生轻重主要受当年气象条件，尤其是降雨量的影响。药剂防治甜叶菊黑斑病以70％百菌清和70％复方甲基托布津最好，使用浓度为500倍液，尤其是70％百菌清残效期长，防效更好。

：Disease rate and disease index of black blotch were surveyed systematically during Stevia growing．The result suggested that the dynamics of Stevia black blotch development showed a “S” shape curve in the fields accord with Logistic model two high peaks occurred with the development of the disease．The severity of Stevia black blotch mainly depends on meteorological condition of the year especially rainfall．70％ Chlorothalonil and 70％ complex Mildethane are good to control Stevia black blotch concentration is 500 times liquid especially residual time of 70％ Chlorothalonil is long and control effect is better．