菌核净、代森锰锌及其混剂对烟草赤星病菌毒力测定

Bioassay of Dimethachlon、Mancozeb and Their Mixtures to Alternaria alternate

运用Horsfall毒力试验设计方案和孢子萌发抑制法分别测定菌核净、代森锰锌及其混剂对烟草赤星病菌(Alternariaalteranta)的毒力,并分别用Wadley方法、Gowing方法、Abbott方法和孙云沛方法等多种评价方法评价所配混剂的增效作用,结果表明,当它们按EC50剂量7:3的比例混配时所得混剂表现明显的增效作用,4种增效作用评价方法所得结果一致,田间防治结果也证明该混剂可有效防治赤星病。

Horsfall’s toxicity design and method of control spore germination were used for toxicity test of Dimethachlon、Mancozeb and their mixtures to Alternaria alternate.Four methods of Wadley、Gowing、Abbott and Sun Yunpei were used to estimate the synergistic interaction of fungicides in mixtures.The results showed that only the mixture(Dimethachlon’s EC50 and Mancozeb’s EC50)in 7∶3 had obvious synergistic interaction.Four estimating methods of synergistic interaction obtained consistent results.The field experiments also illustrated that the tobacco brown,leaf spot could be controlled effectively by application of the mixture.