杀菌剂防治浙贝母灰霉病田间药效调查方法比较

为探索杀菌剂防治浙贝母灰霉病的准确、高效、方便的药效调查方法，选择生产中常用的嘧霉胺、唑醚·氟酰胺、氟菌·肟菌酯3种杀菌剂，采用叶片病斑分级、整株病斑分级、整株病叶率分级、茎秆发病率、茎秆发病分级5种调查方法，对比不同方法对防治效果评价的影响。5种调查方法各有优缺点，叶片病斑分级法样本量大，采集数据多，其结果更接近实际；整株病斑分级法相对简便，可增加植株的取样量，使样本更具代表性，但操作中易产生判断误差；整株病叶率分级法和茎秆发病率法简便，但会放大病害的危害程度，高估或低估药剂防治效果；茎秆发病分级法结合病斑大小、形状等特征能较准确地评价植株发病情况。采用不同评价方法，3种杀菌剂对浙贝母灰霉病的防治效果表现较一致，唑醚·氟酰胺和氟菌·肟菌酯的防治效果较好，防效分别在75.22%～88.83%、68.87～86.82%之间，而嘧霉胺的防治效果略差(57.86%～77.89%)。

Comparison of investigation methods for field control effect of fungicides to gray mold on Fritillaria thunbergii

In order to explore accurate, efficient and convenient efficacy investigation method of fungicides for controlling gray mold on Fritillaria thunbergii, three commonly used fungicides, pyrimethanil, pyraclostrobin·fluxapyroxad and fluopyram·trifloxystrobin were selected to assess by using five investigation methods, including leaf lesion grading method, the whole plant lesion grading method, the whole plant diseased leaf rate method, stalk morbidity method and stalk disease grading method. The results showed that the five investigation methods had their own advantages and disadvantages. Result yielded by the leaf lesion grading method was more accurate while large amount of experimental samples and data were required. The whole plant lesion grading method was relatively simple, and increased the sampling amount, which made the samples more representative, but judgment errors were easily produced. The diseased leaf rate method and the stalk morbidity method sometimes enlarged the degree of disease, enhanced or reduced the evaluation of control effect, although both methods were convenient and objective. In comparison, the stalk disease grading method combined with the size and shape of lesion could more accurately evaluate the whole plant disease. The control effects among the three fungicides with five investigation methods were consistency. However, compared with pyrimethanil (control efficacy of 57.86%-77.89%), pyraclostrobin·fluxapyroxad and fluopyram·trifloxystrobin showed relatively higher control effects of 75.22% -88.83% and 68.87-86.82%, respectively.