甘肃天水苹果黑星病年消长动态调查及防治药剂筛选

Investigation of the annual growth and decline of apple scab and screening of control agents in Tianshui,Gansu Province

为明确苹果黑星病在甘肃天水的年消长动态、发病规律及筛选高效防治药剂,2023年在苹果生长季持续对苹果黑星病的病叶率和病情指数进行了调查,同时选用10种农药制剂进行田间药剂筛选试验。结果表明,天水地区苹果黑星病在5月中旬开始侵染,7月底达到第一次发病高峰,之后进入病情发展缓慢期,8月下旬至9月下旬,病菌又一次侵染秋梢,达到第二次发病高峰,之后进入病菌越冬预备期。田间防治试验表明,25%苯甲·吡唑酯SC 1000倍液、25%戊唑·异菌脲SC 2500倍液、40%氟硅唑EC 1500倍液和20%烯肟·戊唑醇SC 1000倍液的防效达83.56%~93.12%,可作为首选药剂;12.5%烯唑醇WP 1500倍液、25%吡唑醚菌酯SC 800倍液、12.5%腈菌唑EC 1000倍液和40%咪鲜胺EW 800倍液,防效次之,可作为辅助药剂,与首选药剂交替使用。综上所述,本试验明确了苹果黑星病的年消长动态、发病规律,筛选出了高效防治药剂,为苹果黑星病的有效防控提供了理论依据和技术支撑。

In order to clarify the annual dynamics of growth and decline of apple scab and screen effective prevention and control agents in Tianshui,Gansu Province,the rate of diseased leaves and disease index of apple scab were continuously investigated during the apple growing season in 2023,and 10 pesticides were selected for field screening.The results showed that apple scab began to infect apple trees in mid-May,reached the first peak at the end of July,and then entered a slow development period.From late August to late September,the bacteria infected the autumn shoots,reaching the second peak,and then entered the overwinter preparation period of the bacteria in Tianshui area.Field control experiments showed that the control efficiencies of spraying 1,000-time diluted 25%benzoyl·pyrazolate SC,2,500-time diluted 25%pentanazole·isomycin SC,1,500-time diluted 40%fluosilazole EC and 1,000-time diluted 20%enoxime·pentazolol SC,reached 83.56%-93.12%,so these four pesticides could be used as preferred agents.The control efficiencies of 1,500-time diluted 12.5%tenazolol WP,800-time diluted 25%pyrazoletherin SC,1,000-time diluted 12.5%nitribacterazole EC and 800-time diluted 40%amidine EW were lower.Those chemicals could be used as additional agents,alternatively used with preferred agents.In conclusion,this experiment clarified the annual dynamics of growth and decline of apple scab,screened out the effective prevention and control agents,and provided theoretical basis and technical support for the effective prevention and control of apple scab.