6种杀菌剂对建兰茎腐病原菌尖孢镰刀菌的毒力及联合作用

Individual and In-combination Toxicities of Six Fungicides for Controlling Fusarium oxysporum on Cymbidium ensifolium

为筛选出对建兰茎腐病防效好的增效混剂,室内测定6种杀菌剂对建兰茎腐病原菌尖孢镰刀菌的毒力及其联合作用。结果表明:6种杀菌剂对建兰茎腐病原菌尖孢镰刀菌均有不同程度的抑制作用,抑制中浓度EC50的由小到大依次为:咪鲜胺、苯醚甲环唑、多菌灵和肟菌酯、噁霉灵和代森锰锌;设定的4组混剂配方,苯醚甲环唑+多菌灵、多菌灵+肟菌酯混配表现为增效作用,苯醚甲环唑+多菌灵混配的最佳有效成分质量配比为5∶5,共毒系数为378.63;多菌灵+肟菌酯混配的最佳配比则为8∶2,共毒系数为247.80。可见,苯醚甲环唑+多菌灵和多菌灵+肟菌酯合理比例混配能较好防控建兰茎腐病的发生为害。

To select appropriate agents for effective controlling the stem rot disease on Cymbidium ensifolium,toxicities of 6 fungicides,either individually or in combination,were tested in laboratory.All 6 fungicides showed varying degrees of inhibition on Fusarium oxysporum,with EC50 that ranked in the order of prochlorazdifenoconazolecarbendazim or trifloxystrobinhymexazol or mancozeb.In combination,a synergism between difenoconazole and carbendazim,as well as between trifloxystrobin and carbendazim,was observed.The optimum ratio for the difenoconazole/carbendazim combination was 5/5 with a co-toxicity coefficient of 378.63,while that for trifloxystrobin/carbendazim,8/2 with a coefficient of 247.80.