大黄提取液防治黄瓜白粉病的初步研究

对中草药大黄提取液防治黄瓜白粉病的保护活性、稳定性、持效期及押菌谱等作了初步研究。结果表明，大黄提取液的100倍液防效迭90％以上，优于粉锈宁(15％WP)1000倍液的防效(73．41％)；其酸碱稳定性与热稳定性都非常强；保护作用的持效期至少可达6d；押菌谱测试结果表明，它对供试的小麦根腐病菌Cochliobolus sativus等20种真菌都表现出一定的抑制作用。

Control Effect of the Extracts from Rheum palmatum on Powdery Mildew of Cucumber

In this paper, the extract from Rheum palmatum was tested for prevention effect on powdery mildew of cucumber,stability,duration of the efficacy and restraint spectrums of fungi.The results demonstrated that 100-fold Rheum palmatum extraction was effective to control the disease and its efficacy was superior to 15% WP Triadimefon 1000-fold,which was up to 90.14%. The efficacy was stable in different temperatures and pH values.The duration of the preventive efficacy of Rheum palmatum extraction to S.fuliginea could last over 6 days,and also significantly to restrain many other fungi such as Cochliobolus sativus,Exserohilum turcicum ,et al.