7 种杀菌剂对马铃薯晚疫病菌的室内毒力测定及田间防控效果

采用含毒介质培养法测定了68％精甲霜灵·锰锌(金雷)水分散粒剂、64％恶霜·锰锌(杀毒矾)可湿性粉剂、72％霜脲·锰锌(克露)可湿性粉剂、50％烯酰吗啉(安克)可湿性粉剂、25％嘧菌酯(阿米西达)悬浮剂、18.7％烯酰·吡唑酯(凯特)水分散粒剂、70％代森锰锌可湿性粉剂等7种药剂对马铃薯晚疫病病菌的毒力,并将7种药剂组成9个药剂组合,进行田间马铃薯晚疫病防治试验.结果表明:除70％代森锰锌及杀毒矾外,其余5种杀菌剂对马铃薯晚疫病菌菌丝生长都有较好的抑制作用,EC50在0.017～0.243 mg/L之间;田间试验各药剂组合均具有明显的防治效果和增产效果,其中代森锰锌+克露+安克+克露、代森锰锌+克露+凯特+克露、代森锰锌+克露+金雷+克露、代森锰锌+安克+金雷+安克、代森锰锌+安克+凯特+安克等5个组合对晚疫病防效均达90％以上,增产率13.92％～18.54％,每667 m2增加纯收入660～905元.根据药剂的防效和增收效果,提出防治广东冬种马铃薯晚疫病药剂交替使用组合方法为:前期使用代森锰锌保护剂,发病期间使用克露+金雷+克露、安克+金雷+安克、安克+凯特+安克.

Toxicity bioassay and field trial of 7 fungicides against Phytophthora infestans from potatoes

The toxicities of seven fungicides including 68% Metalaxyl mancozeb WG, 64% Oxadixyl mancozeb WP,72% Cymoxanil mancozeb WP, 50% Acrobat WP, 25% Azoxystrobin SC, 18.7% Cabrio-team WG, and 70% Mancozebon WP on phytophthora infestans were determined by using in vitro radial growth assay, respectively. Nine combinations from these seven fungicides were used to control potato late blight in the field trial. The results indicated that, except for 70% Mancozeb WP and 64% Oxadixyl mancozeb WP, the other five fungicides showed good inhibition on the growth of hypha of phytophthora infestans, and the values of EC50 were between 0.017 mg/L and 0.243 mg/L. All the combinations based on the seven fungicides showed good control efficiency and yield-increasing effect in the field trial. The control effects on potato late blight from five combinations including 70% Mancozeb WP+72% Cymoxanil mancozeb WP+50% Acrobat WP+72% Cymoxanil mancozeb WP, 70% Mancozeb WP +72% Cymoxanil mancozeb WP +18.7% Cabrio -team WG +72% Cymoxanil mancozeb WP, 70% Mancozeb WP +72% Cymoxanil mancozeb WP +68% Metalaxyl mancozeb WG +72% Cymoxanil mancozeb WP, 70% Mancozeb WP+72% Cymoxanil mancozeb WP+68% Metalaxyl mancozeb WG+50% Acrobat WP and 70% Mancozeb WP+72% Cymoxanil mancozeb WP+18.7% Cabrio-team WG+50% Acrobat WP were more than 90%, and the yield-increasing production rates were from 13.92% to 18.54%, which could increase the net income of 660~905 Yuan per 666.7 m2. According to the above results, the following method was provided to control potato late blight in winter of Guangdong Province: using 70% Mancozeb WP as protective agent in the early stage of infection, then using 72% Cymoxanil mancozeb WP+68% Metalaxyl mancozeb WG+72% Cymoxanil mancozeb WP or 72% Cymoxanil mancozeb WP +68% Metalaxyl mancozeb WG +50% Acrobat WP or 72% Cymoxanil mancozeb WP +18.7% Cabrio-team WG+50% Acrobat WP during the period of disease.