吡唑醚菌酯及其复配药剂对马铃薯晚疫病的毒力测定及药效试验

Toxicity and efficacy test of pyraclostrobin and its compound agents against potato late blight

为了筛选出吡唑醚菌酯与其他药剂混配对防治马铃薯晚疫病的较好配方,延缓抗药性的产生,采用菌丝生长速率法测定了吡唑醚菌酯与氟吡菌胺复配,以及吡唑醚菌酯与百菌清复配对马铃薯晚疫病菌的联合毒力,从中筛选出具有较好抑制作用的配方,并通过田间药效试验评价了复配药剂对马铃薯晚疫病的防治效果。试验结果表明:在离体条件下所有复配组合均对抑制马铃薯晚疫病菌表现相加作用,当吡唑醚菌酯与氟吡菌胺的混配比例为1∶5时,增效系数最大,为1.29;当吡唑醚菌酯与百菌清的混配比例为9∶1时,增效系数最大,为1.26。在田间药效试验中,两种复配药剂对马铃薯晚疫病具有良好的防治效果,田间防效分别达到86.50%和87.40%。

To screen effective chemical mixtures of pyraclostrobin with other fungicide against Phytophthora infestans,and delay the onset of fungicide resistance,the toxicities of mixtures of pyraclostrobin with flupicolide and chlorothalonil on Phytophthora infestans were determined by measuring the growth rate of mycelium in laboratory. The ratios of mixtures that had the best efffect on controlling the mycelium growth were screened out, and the control efficacy on potato late blight was assessed through field trial. The results showed that all mixtures exhibited additive effects on Phytophthora infestans in vitro. When the mass ratio of mixture of pyraclostrobin and flupicolide was 1∶5,the synergistic ratio （SR） was 1.29. When the mass ratio of mixture of pyraclostrobin and chlorothalonil was 9∶1,the synergistic ratio （SR） was 1.26. Field trial demonstrated that the two mixtures both had higher control efficacy,and their control effects were 86.5% and 87.4% respectively on potato late blight.