防治大豆根腐病的药剂筛选及田间应用

Fungicides screening and field application for controlling soybean root rot

[目的]针对大豆根腐病,筛选出具有显著防效的药剂。[方法]采用菌丝生长速率法,测定咯菌腈等10种杀菌剂对尖孢镰刀菌和大豆疫霉菌的活性,并进行田间防效试验。[结果]咯菌腈、咪鲜胺和戊唑醇3种杀菌剂单剂对2种病原菌抑菌效果较好,对尖孢镰刀菌的EC50值分别为0.295、0.035、0.444 mg/L,对大豆疫霉菌的EC50值分别为0.324、0.045、0.077 mg/L。咯菌腈∶咪鲜胺(5∶1)和咪鲜胺∶戊唑醇(5∶1)复配时对尖孢镰刀菌增效系数分别为2.143、1.566,对大豆疫霉菌的增效系数分别为2.063、2.031,具有较好的增效作用。田间试验结果表明:咯菌腈+咪鲜胺(5∶1)200 g/100kg种子和咪鲜胺+戊唑醇(5∶1)200 g/100kg种子包衣对大豆根腐病的防治效果分别为85.57%、84.54%。[结论]咯菌腈∶咪鲜胺(5∶1)与咪鲜胺∶戊唑醇(5∶1)二元混配,可以有效防治大豆根腐病。

[Aims]This study aims to screen out chemical agents with remarkable effects for the prevention and control of soybean root rot.[Methods]10 Fungicides such as fludioxonil were determined by the mycelial growth rate method to soybean root rot,then field control effect trials were carried out.[Results]The 3 fungicides fludioxonil prochloraz and tebuconazole had preferable fungicidal effects on soybean root rot,and the EC50 against F.oxysporum was 0.295,0.035,and 0.444 mg/L respectively;the EC50 against P.sojae was 0.324,0.045 and 0.077 mg/L respectively.The synergistic value of fludioxonil and prochloraz(5:1),prochloraz and tebuconazole(5:1)against F.oxysporum was 2.143 and 1.566;the synergistic value against P.sojae was 2.063 and 2.031.The results of field experiments showed that the control efficacy of fludioxonil and prochloraz(5:1)200 g/100kg seeds coating and prochloraz and tebuconazole(5:1)200 g/100kg seeds coating on soybean root rot could reach 85.57%and 84.54%.[Conclusions]The binary mixed pair of fludioxonil and prochloraz(5:1)and prochloraz and tebuconazole(5:1)could prevent and control soybean root rot effectively.