几种化学杀菌剂对苹果轮纹病的药效评价

Evaluation on the effects of several chemical fungicides for control of Botryosphaeria dothidea

为解决当前苹果轮纹病对传统药剂产生抗性问题,以70%代森锰锌可湿性粉剂为对照,在室内测试了10%苯醚甲环唑水分散粒剂,250g·L-1嘧菌酯悬浮剂等6种化学杀菌剂的室内毒力;另外在田间设置小区试验,测定了这些药剂在不同使用质量浓度条件下对苹果轮纹病的防治效果。结果表明,除50%醚菌酯水分散粒剂以外,其他几种化学药剂均表现出优于70%代森锰锌的抑菌和防病效果。在室内测试中,10%的苯醚甲环唑水分散粒剂表现出最高的毒力,EC50为0.017mg·L-1;250g·L-1嘧菌酯悬浮剂800倍浓度在田间测试中表现出最好的防病效果,采收期防效达92.39%;贮藏15d和30d防效分别达到100%和98.59%。该试验结果为部分新药剂的产品登记以及为生产上选择适于防治苹果轮纹病的药剂种类提供了依据。

In order to solve the problem of Botryosphaeria dothidea on resistance to traditional fungicides,bioassay tests were made for 6 fungicides including 10% water-dispersible granules of difenoconazole,250 g·L^-1 azoxystrobin suspension concentrate etc.against B.dothidea in laboratory.Field tests of these fungicides with different concentrations were made for control of the disease on apple trees.The results showed that except water-dispersible granules of 50% kresoxim-methyl,the other fungicides expressed stronger inhibitory effects against mycelium growth than that of 70% mancozeb wettable powder.10% difenoconazole water dispersible granules showed the highest toxicity with EC50 of 0.017 mg L-1.In the field tests,250 g· L^-1 azoxystrobin suspension concentrate at the concentration of 800 times concentration was the best one for control of this disease at harvest stage,with effectiveness of 92.39% ;and after stored for 15 and 30 d effectiveness reached 100% and 98.59%.These tests provided a sound basis for fungicide registration and for choice of suitable fungicides for control of B.dothidea in apple production.