18种杀菌剂原药及其复配对油菜菌核病的室内毒力测定OA

To screen fungicides and their binary combinations for effective prevention and control of sclerotinia stem rot in Brassica napus and reduce the application of fungicides,this study employed the mycelial growth rate method to determine the indoor toxicity of 18 fungicide technical materials and 6 mixtures against Sclerotinia sclerotiorum.The results showed that the 18 fungicide technical materials exerted inhibitory effects on S.sclerotiorum.Among them,98%prothioconazole and 97%pydiflumetofen had stronger control effects,with EC50 values of 0.024 and 0.043 mg/L,respectively.Six binary combinations of fungicide technical materials with strong effects and different inhibition mechanisms were selected for indoor toxicity determination.The results showed that the combination of prochloraz∶pydiflumetofen=1∶5 had the lowest EC50(0.019 mg/L)and a co-toxicity coefficient of 234.85.The results of detached leaf control efficacy verification were basically consistent with those of the indoor toxicity determination.The control efficacy of pydiflumetofen alone and the prochloraz:pydiflumetofen combination reached 100%.Considering both indoor toxicity and detached leaf control efficacy,98%prothioconazole,97%pydiflumetofen,and the combination of prochloraz∶pydiflumetofen=1∶5 had stronger inhibitory effects on the mycelial growth of S.sclerotiorum and also showed significant control efficacy on detached leaves.They could be recommended as the preferred options for subsequent field trials.