四氟醚唑对黄瓜的安全性及其对黄瓜白粉病的防治效果

为明确四氟醚唑对黄瓜植株的安全性，采用浸种及茎叶喷雾处理的方法测定其对不同生长时期黄瓜植株的影响，采用子叶保湿培养法测定白粉病菌对其敏感性，并在田间进行防治白粉病的药效试验，综合评价了四氟醚唑对黄瓜白粉病的效果。浸种处理后，黄瓜子叶上白粉病发病率明显降低，对黄瓜株高和根长的抑制率、茎周增长率及叶绿素含量增加率与己唑醇相比均较低；发芽期及幼苗期的黄瓜植株使用四氟醚唑处理，新生节间均出现轻微的抑制伸长现象；4％四氟醚唑水乳剂对黄瓜白粉病菌的EC50为0．8146mg／L，敏感毒力高于50％醚菌酯水分散粒剂；田间间隔期10天喷雾，在末次药后7天对黄瓜白粉病的防治效果为76．02％～85．77％，与5％己唑醇水乳剂防效相当，明显高于50％醚菌酯水分散粒剂的防效。表明四氟醚唑对黄瓜生长安全且用药间隔期长，是防治白粉病的高效轮换药剂。

Safety of tetraconazole to cucumber and its efficacy against cucumber powdery mildew

Cucumber seed and seedling was imbibed and sprayed respectively to evaluate the safety of tetraconazole to cucumber, while the sensitivity of Sphaerotheca fuliginea to tetraconazole was tested with cotyledon assay and field experiment was also conducted at the same time. The inhibitory rates to powdery mildew, plant height, root length and increase rate of stem diameter and chlorophyll of tetraconazole were lower than that of hexaconazole after seed-soaking treatment. Inhibition to internode length was slight when tetraconazole was used at the different periods of cucumber growth. The EC₅₀ of tetraconazole against S.fuliginea was 0.8146 mg/L, so the sensitivity of this pathogen to tetraconazole was much higher than that to kresoxim-methyl. The control efficacies were 76.02%- 85.77% 7 days after last treatment in field. The study indicated that tetraconazole was safety to cucumber in the whole growth period. It has a long application interval and can be used as an alternative fungicide in cucumber powdery mildew control.