5种杀菌剂对马铃薯黑痣病的病菌毒力及田间防效

马铃薯黑痣病(Rhizoctonia solani)是一种土传病害,危害呈逐年加重趋势。本研究进行了5种杀菌剂对病菌的毒力测定和病害田间防效试验。结果表明:抑霉唑、嘧菌酯抑菌作用较好,EC50分别为4.46μg·mL-1、8.32μg·mL-1,相关系数r均大于0.91。5种药剂在田间防病中,噻氟菌胺沟施浓度过高对马铃薯出苗产生药害,相对出苗率为92.3%,与对照有显著性差异;嘧菌酯、噻氟菌胺、百菌清、抑霉唑沟施和拌种对地中茎防病效果均在83%以上;抑霉唑(沟施)、嘧菌酯(沟施和拌种)、百菌清(沟施)对预防因病造成植株死亡效果较好,防效分别为71.6%、69.3%、67.4%、67.3%;嘧菌酯预防薯块带菌效果最好,沟施和拌种防病效果分别为90.7%、86%。

Virulence and Control Efficacy in Field of Five Fungicides on Rhizoctonia solani of Potato

Black scurf diseas e(Rhizoctonia solani) is a soil-borne disease,and the trend of damage by the disease is increasing year by year.The purpose of this study was to test virulence and effectiveness in field of five fungicides on the pathogen.Imazalil and Azoxystrobin had better antimicrobial effects,with EC50 being only 4.46 μg·mL-1 and 8.32 μg·mL-1,respectively,and the correlation coefficient r > 0.91.For experiment field,Thifluzamide of high concentration produced the toxicity on potato emergence and the relative rate of seedling emergence was 92.3%,significantly different with the control.The control efficiency of Azoxystrobin,Thifluzamide,Chlorothalonil,and Imazalil on the subterranean stem of potato was all above 83% by both furrow application and seed dressing.Analysis of the potato plant mortality indicated that control efficiency of Imazalil(furrow application),Azoxystrobin(furrow application and seed dressing),and Chlorothalonil(furrow application) was 71.6%,69.3%,67.4%,and 67.3%,respectively.Azoxystrobin was the best against the tuber fungi of potato,with its effectiveness being 90.7% by furrow application and 86% by seed dressing.