六种铜制剂对苹果树腐烂病菌抑制作用的持效期及影响因素

Effective Duration and Influencing Factors of Six Cupric Pesticides Against Valsa mali

以生产上常用的6种铜制剂为供试药剂,以80%代森锰锌可湿性粉剂和29%石硫合剂水剂为对照,采用改良的孢子萌发法,测定了不同铜制剂对苹果树腐烂病菌分生孢子萌发抑制作用的持效期,并进一步测定了光照和降雨对药剂持效期的影响以及各药剂在果树叶片上的展着性,为铜制剂的田间正确应用及防治苹果树腐烂病提供参考。结果表明:6种供试铜制剂中,倍量式波尔多液(Cu∶CaO∶H_2O=1∶2∶200)对苹果树腐烂病菌分生孢子萌发的抑制率最高,持效期长达20d以上,且药后20d抑菌率仍达87.97%,光照和降雨对其抑菌作用无显著性影响,药剂在叶正面和叶背面展着性适中。77%硫酸铜钙可湿性粉剂和12%松脂酸铜乳油也具有较长的持效期,但降雨和光照对其防效有不同程度的影响。2种对照药剂中的29%石硫合剂水剂的持效期、抗光解和抗雨水冲刷能力都略次于倍量式波尔多液。而80%代森锰锌可湿性粉剂则持效期短,光照和降雨对其抑菌作用影响显著。推荐使用倍量式波尔多液进行田间防控苹果树腐烂病。

Six cupric pesticides were used as tested agents,80% lime sulphur WP and 29% mancozeb SL were used as chemical control,their lasting time,influence factors and spreading behavior were studied by spore germination method in order to supply reference for cupric pesticides use and preventing apple tree Valsa canker.The results showed that lime times bordeaux mixture（Cu∶CaO∶H2O=1∶2∶200）had the highest inhibition effect and longest lasting period（more than 20days）among the tested fungicides,and the inhibition ratio was 87.97% 20 days after spraying.Light and rainfall had no significant effect on its inhibition activity,77% copper calcium sulphate WP and 12%resin acid copper salt EC,which had medium ability on spreading,suffered different influences from light and rainfall.29%lime sulphur had worse effect than lime times bordeaux mixture.While,light and rainfall had significant effect on 80%lime sulphur WP,which lasting only 7days.It was recommended to use lime times bordeaux mixture to control apple Valsacanker.