YANG Yu-hong1,GONG Hui-zhi1,YANG Cui-rong1,FENG Lan-xiang1,XU Xiang-rong2,QIAN Yi-xin2,XIE Bing-yan1*
1Institute of Vegetables and Flowers,Chinese Academy of Agricultural Sciences,Beijing 100081,China; 2Beijing Qingyuanbao Biological Science and Technology Co.,Ltd,Beijing 100193，China
Abstract：Through screening from 7 different propotions in greenhouses,0.5 % physcion is identified to display the best efficient control on cucumber powdery mildew,which reaches about 90 % control efficacy below 1 000-fold dilution,signifcantly higher than this of triadimefon and emodin AM.Then the action mode,prevention duration,stability,control techniques and field control efficacy of 0.5 % physcion were further investigated.The results showed that 0.5 % physcion has both protection and control activities.And the former is more prominent than the later,showing 94 % control efficacy 14 days after inoculation.The duration of the protective efficacy of 0.5% physcion could last 3-4 days.The efficacy was stable in different temperatures and illumination during cucumber growth.The control efficacy was also significant stable in field trial.
