防治牡丹根腐病的有效药剂筛选

采用菌丝生长速率法和孢子萌发法，分别测定了咪鲜胺、醚菌酯、苯醚甲环唑、百菌清、多菌灵、代森锰锌等6种杀菌剂对牡丹根腐病菌的室内毒力。结果表明，6种药剂对病菌菌丝生长的EC50大小顺序为：咪鲜胺<多菌灵<代森锰锌<苯醚甲环唑<百菌清<醚菌酯，其中以咪鲜胺对牡丹根腐病病菌的菌丝生长抑制作用最强， EC50为0.200 mg/L；多菌灵、代森锰锌、苯醚甲环唑、百菌清依次减弱，醚菌酯的抑制菌丝生长的作用最小，EC50为33.98 mg/L。6种药剂对病菌孢子萌发的EC50大小顺序为：百菌清<咪鲜胺<苯醚甲环唑<多菌灵<代森锰锌<醚菌酯；其中以百菌清对牡丹根腐病菌的孢子萌发抑制作用最强，EC50为0.343 mg/L；咪鲜胺、苯醚甲环唑、多菌灵、代森锰锌依次减弱，醚菌酯抑制孢子萌发的作用最小，EC50为38.4 mg/L。

Toxicity of six fungicides to the pathogen of the tree peony root rot

Toxicity of six fungicides to Fusarium solani causing the tree peony root rot was tested by means of mycelial growth method and spore germination method in the laboratory. The results of mycelial growth method showed that the EC50 of the 6 fungicides could be arranged in order of decreasing value: prochloraz, carbendazim, mancozeb, difenoconazole, chlorothalonil and kresoxim methyl. The inhibitory effect of prochloraz was the strongest among the fungicides tested. The results of spore germination method indicated that chlorothalonil, with EC50 value of 0.343 mg/L, had the highest toxicity to the pathogenic fungus. Toxicity of prochloraz, difenoconazole, carbendazim and mancozeb was gradually weakened, and that of kresoxim methyl was the lowest.