杜仲灰斑病防治药剂的筛选

摘要

为筛选出有效防治杜仲灰斑病的药剂在生产上应用，采用菌丝生长速率法，研究甲基托布津、百菌清、中生菌素、多抗霉素、多菌灵和苯醚甲环唑等6种杀菌剂对杜仲灰斑病菌的室内毒力，并进行了田间药效试验。结果表明：室内毒力测定，多抗霉素、多菌灵和苯醚甲环唑对灰斑病菌有较好的抑制作用，其EC50分别为1．67μg/mL、0．96μg/mL和0．18μg/mL；而甲基托布津、百菌清和中生菌素对灰斑病菌的毒力相对较弱。经田间药效试验，多抗霉素1000倍液、多菌灵2000倍液和苯醚甲环唑2500倍液对杜仲灰斑病有较好的防治效果，第2次施药10 d后的防效分别可达74．36％、80．82％和79．67％，显著优于其他药剂处理，可作为防治杜仲灰斑病的首选药剂。%In order to screen effective fungicides controlling gray leaf spot disease of E.ulmoides,the toxicity of six fungicides(thiophanate methyl,chlorothalonil,Zhongshengmycin,polyoxins,carbendazim and difenoconazole)on E.ulmoides gray leaf spot pathogen were determined in laboratory using mycelium growth rate method.The field trial of the six fungicides controlling gray leaf spot disease of E.ulmoides was also carried out under the field condition. Results:Thiophanate-methyl, chlorothalonil and zhongshengmycin had worse antimicrobial effect on A.tenuis.polyoxin,carbendazim and difenoconazole had better antimicrobial effect on A.tenuis than others,with EC50 of 1.67μg/mL,0.96μg/mL and 0.18μg/mL,respectively.The field trial results also confirmed that ten days after second sprayed application, the control efficiency of polyoxin 1 000 times,carbendazim 2 000 times and difenoconazole 2 500 times reached 74.36%, 80.82% and 79.67%, respectively. Control eficiency of the three agents was significantly better than that of other treatments.Therefore,polyoxin,carbendazim and difenoconazole could be recommended as the first-choice fungicides to control gray leaf spot disease of E.ulmoides.