花生白绢病防治药剂的筛选

Screening of fungicides for the control of peanut stem rot

为筛选出防治花生白绢病的药剂,采用菌丝生长速率法和菌核萌发法测定了5种杀菌剂对花生白绢病菌的室内毒力,并进行了田间防效试验。室内毒力测定结果表明:噻呋酰胺及其复配制剂对白绢病菌菌丝生长的抑制性较强,EC_(50)为37.12μg/L~80.35μg/L,菌核·福美双的抑制作用较弱,EC_(50)为9541.39μg/L。含有噻呋酰胺的药剂抑制菌核的产生,浓度越高,菌核产生量越少;而菌核·福美双对产菌核抑制较弱。5种药剂皆抑制菌核的萌发,噻呋酰胺及其复配制剂抑制效果随时间延长而降低,菌核·福美双对菌核萌发的抑制效果较稳定。田间试验结果表明:除噻呋·戊唑醇外,其他四种药剂对花生白绢病都有一定的防治效果,防效为8.36%~28.26%;除噻呋·戊唑醇与菌核·福美双外,其余三种药剂处理对花生的荚果产量均有促进作用,增产率均在20%以上。通过室内和田间试验,筛选获得具有较好防治和增产效果的复配药剂噻呋·吡唑酯和噻呋·嘧菌酯。

In order to screen fungicides for managing peanut stem rot,the toxicity of five fungicides against Athelia rolfsii was determined through inhibiting mycelial growth and sclerotia germination under laboratory condi-tions.Controlling efficacy to peanut stem rot was also evaluated in the field.Results of in vitro assay showed that thiofuramide and its compound formulations exhibited stronger inhibition on the mycelial growth of A.rolfsii,with EC_(50) values ranging from 37.12μg/L to 80.35μg/L.In contrast,thiram·dimetachlone exhibited weaker inhibition on the mycelial growth,with an EC_(50) value of 9541.39μg/L.The medium containing higher amounts of thiofuramide resulted in less sclerotia production by A.roflsii,while the medium with different amounts of thiram·dimetachlone did not show significant difference.All five fungicides inhibited A.rolfsii sclerotia germination.Thiofuramide and its compound formulations on sclerotia germination decreased from 48 hours to 1 week,whereas thiram·dimetachlone exhibited consistent performance.Four fungicides,excluding thiofur·tebuconazole,exhibited field control efficacy ranging from 8.36%to 28.26%.Thiofuramide,thiofur·pyrazolate,and thiofur·azoxystrobin treat-ments increased peanut yield by over 20%compared to the untreated control.Based on results of in vitro assay and field tests,thiofur·pyrazolate and thiofur·azoxystrobin,were found to be effective against A.rolfsii.