Control effects and optimal spraying time of fungicides to apple rust caused by Gymnosporangium yamadae | 苹果锈病防治药剂筛选及施药适期研究

Chinese. 为了筛选防治苹果锈病的有效杀茵剂，明确其最适施药时期，通过先接种后施药和先施药后接种的方法，测试了8种药剂对苹果锈病的内吸治疗效果和7种药剂的保护效果。结果表明，8种内吸治疗剂中，氟硅唑、戊唑醇、苯醚甲环唑3种药剂对苹果锈病的治疗效果为100%；嘧霉胺和吡唑醚菌酯两种药剂的治疗效果分别为81.58%和74.52%；多抗霉素、嘧茵环胺和甲基硫茵灵3种药剂对苹果锈病没有治疗作用。7种保护剂中，代森锰锌、百菌清、吡唑醚茵酯和氟硅唑在接种前12d内施药，保护效果皆为100%；异菌脲和甲基硫茵灵的保护效果分别为90.58%和90.21%；多抗霉素没有保护作用。上述结果表明，三唑类药剂是防治苹果锈病有效的内吸治疗剂，在病菌侵染后的5d内使用效果较为理想。代森锰锌、百茵清、吡唑醚茵酯等是防治苹果锈病的有效保护剂，持效期可达7～10d。

English. In order to screen effective fungicides and to make clear the appropriate spraying time to control apple rust caused by Gymnosporangium yamadae, systematic effects of 8 fungicides and protective effects of 7 fungicides on apple rust were tested by applying the fungicides after and before inoculating basidiospores of the fungi onto young apple leaves. The results showed that systematic effects of three triazole fungicides, flusilazole, tebuconazole and difenoconazole were 100%. Systematic effects of pyrimethanil and pyraclostrobin, were 81.58% and 74.52%, respectively. Polyoxin, cyprodinil and thiophanate-methy had no systematic effect. Protective effects of three fungicides, mancozeb, chlorothalonil, pyraclostrobin and flusilazole, were 100%. Protective effect of iprodione and thiophanate-methyl, were 90.58% and 90.21%, respectively. Polyoxin didn’t show protective effect. Triazole fungicides, such as flusilazole, tebuconazole and difenoconazole, were the effective systematic fungicides to control apple rust. Best time to apply the fungicides was within 5 days after the fungi infection. Mancozeb, chlorothalonil and pyraclostrobin were the best protective fungicides on protecting apple leaves against infection of rust fungi and the protective effect would maintain for 7 to 10 days.