白僵菌对茶小绿叶蝉田间防效的关键影响因素研究

Key factors influencing control effect of Beauveria bassiana against Empoasca spp.in tea plant

白僵菌孢子萌发率和萌发速度是影响其田间防效的关键因素。通过对球孢白僵菌YP9（CCTCC No：M209238）孢子萌发的关键影响因素进行研究，得到以下田间应用条件：营养物质为2％麸皮浸出液（自然pH）；孢子悬浮液喷洒浓度为5×10^7孢子／mL；在气温为23℃～28℃时喷洒。经昆明和无锡两试验地田间防效验证，该白僵菌在上述条件下对荼小绿叶蝉的田间防效高达65％，与茶农常用化学农药——天王星防效相当。

The high control effect of Beauveria bassiana （Bb） against Empoasca spp. in the field depends heavily on the high conidial germination rate and the rapid germ tube extension. Thus, several key factors influencing conidial germina- tion were investigated to increase the conidial germination rate and the speed of germ tube extension of Bb. Then, the field application way of Bb YP9 were obtained as follows ： the concentration of wheat bran extract added was 2% （ natural pH） ; The conidial suspensions were sprayed at 5 ~ 107 conidia mL-1 ; The suspensions were sprayed when the air temperature was 23 ~C ~ 28 ~C. The field trials were conducted to evaluate the control efficacy of Bb YP9 against Empoasca spp. of tea plant in Kunming and Wuxi area. As a result, the maximal control efficacy of Bb YP9 reached 65%, almost as high as that of pesticide.