防治牡丹根腐病的有效药剂筛选

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

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 Fusariurn solani causing the tree peony root rot was tested by means of myce- iial 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.