咖啡锈病发生规律调查及施药适期研究

Occurrence regularity investigation and spraying time of fungicides to coffee leaf rust

为筛选出防治咖啡锈病的有效杀菌剂,明确其施药适期,以提高防治效果,笔者调查咖啡锈病发生规律,在温室采用先接种后施药和先施药后接种的方法测试4种杀菌剂的防治效果,并验证筛选药剂的田间防治效果。结果表明:咖啡锈病发生盛期为10月至翌年3月。叶片接种夏孢子后72 h喷施4种杀菌剂,一定浓度的4种杀菌剂均有较好的治疗和预防效果。接种病原菌后10 d施用75%戊唑·嘧菌酯水分散粒剂(WG)3000倍液和25%嘧菌酯悬浮剂(SC)1500倍液,治疗效果分别为94.19%和83.87%;75%戊唑·嘧菌酯WG 3000倍液和25%嘧菌酯SC 1500倍液具有较好的预防效果,预防持效期分别为15 d和10 d。间隔9 d施药3次后田间防治39 d和68 d,75%戊唑·嘧菌酯WG 3000倍液相对防效分别为92.00%和81.08%,25%嘧菌酯SC 1500倍液的相对防效分别为88.29%和69.05%。可依据咖啡锈病的发生规律适时选用75%戊唑·嘧菌酯WG和25%嘧菌酯SC。

In order to select effective fungicides for the prevention and control of coffee leaf rust and determine the appropriate time of application to improve the control efficiency,the author investigated the occurrence regularity of coffee leaf rust,tested the control effects of four fungicides on coffee leaf rust by inoculation before application and application before inoculation in greenhouse,and verified the control effects of the selected fungicides in field.The results showed that the peak occurrence period of coffee leaf rust was from October of that year to March of the following year.Four fungicides were sprayed 72 hours after inoculation with uredospore on the leaves,and all four fungicides at certain concentrations had better therapeutic and preventive effects.Tebuconazole·azoxystrobin 75%water dispersible granule(WG)3000 times dilution and azoxystrobin 25%suspension concentrate(SC)1500 times dilution were applied 10 days after inoculation,and the therapeutic effects were 94.19%and 83.87%,respectively.Tebuconazole·azoxystrobin 75%WG 3000 times dilution and azoxystrobin 25%SC 1500 times dilution had better preventive effects,with a duration of prevention of 15 days and 10 days,respectively.Thirty‐nine days and 68 days after spraying three times at an interval of nine days in field,the relative control effects of tebuconazole·azoxystrobin 75%WG 3000 times dilution were 92.00%and 81.08%,respectively,and the relative control effects of azoxystrobin 25%SC 1500 times dilution were 88.29%and 69.05%,respectively.According to the occurrence regularity of coffee leaf rust,tebuconazole·azoxystrobin 75%WG and azoxystrobin 25%SC can be selected timely.