常用杀菌剂对湘莲腐败病病原菌的室内毒力和安全性测定OA

To screen the highly effective and safe chemical agents suitable for controlling the lotus rot disease in Hunan,this study employed the mycelial growth rate method to evaluate the indoor inhibitory activities of six commonly used fungicides against the pathogenic fungi(Fusarium solani and Fusarium commune)of this disease.According to the inhibitory results,the most effective fungicide was selected,and the safety of this fungicide on lotus seedlings was assessed through 3 application methods:foliar spraying,bud soaking,and root immersion.The results indicated that all the six tested fungicides exhibited inhibitory effect against the pathogens.Among them,prochloraz 25%EC demonstrated the highest inhibitory activity against both Fusarium species,with median effective concentration(EC50)values below 0.1 mg/L.Notably,it showed the strongest inhibitory efficacy against F.solani,with an EC50 value of 0.043 mg/L.Application of a 1 000-fold dilution of prochloraz 25%emulsifiable concentrate caused no phytotoxicity symptoms in seed lotus seedlings,which indicated high safety of this fungicide at this concentration for seed lotus seedlings.