不同化学杀菌剂与多抗霉素混配对压砂西瓜炭疽病的联合生物活性及田间防效

目的]明确不同化学杀菌剂与生物农药多抗霉素混配对宁夏压砂西瓜炭疽病的防治效果。方法]采用菌丝生长速率法、Wadley法和田间喷雾法,测定了4种化学杀菌剂对压砂西瓜炭疽病的室内生物活性和田间防效,并将活性较强、防效较优的化学农药与多抗霉素混配测定其对西瓜炭疽病的协同增效作用。结果]筛选出防治压砂西瓜炭疽病效果较佳的化学杀菌剂咪鲜胺、苯甲·嘧菌酯2种,并确定了其与多抗霉素的最佳质量配比分别为1∶2、1∶3,平均防效可达82%,均高于单剂防效。结论]咪鲜胺、苯甲·嘧菌酯可作为宁夏压砂西瓜炭疽病防治的首选化学药剂,与多抗霉素混配对西瓜炭疽病防效优于单剂,可降低化学农药使用量和减少农药抗药性,不同药剂组合可交替使用。

Combined Toxicity and Field Efficacy of Mixture of Different Chemical Fungicides and Biological Polyoxin against Anthracnose in Gravel-covered Watermelon

Aims] This paper aims to confirm the control effect of the mixture of different chemical fungicides with biological polyoxin for control of gravel-covered watermelon anthracnose in Ningxia. Methods] Mycelium growth rate method, Wadley method and field spray method were used to determine the indoor toxicity and field efficacy of four kinds of chemical fungicides on gravel-covered watermelon anthracnose. The synergistic effect of mixture of biological polyoxin and chemical fungicides with higher toxicity and better prevention ability was tested for control of gravel-covered watermelon anthracnose. Results] Two kinds of chemical fungicides, prochloraz and difenoconazole azoxystrobine, were selected, which have better effects for control of gravel-covered watermelon anthracnose. The optimal ratio of prochloraz and polyoxin is 1:2 and that of difenoconazole azoxystrobine and polyoxin is 1:3. The prevention effect can reach about 82% on average, which is higher than that of one single fungicide. Conclusions] Prochloraz and difenoconazole azoxystrobine can be used as the first choice of chemical fungicides in control of gravel-covered watermelon anthracnose in Ningxia and the mixture of chemical fungicide with biological polyoxin is superior to chemical fungicide. It can reduce the amount of chemical fungicide and the resistance. Different combinations can be used alternately.