EFFECTIVENESS OF TRIAZOLE FUNGICIDES FOR THE CONTROL OF BROWN EYE SPOT ON COFFEE SEEDLINGS

ABSTRACT Triazole fungicides and their mixtures with insecticides are usually employed for the control of coffee rust and leaf miner in coffee crops. In this study these chemicals were evaluated for the control of brown eye spot, caused by Cercospora coffeicola, another important disease of this crop. Three experiments were carried out in a greenhouse with coffee seedlings of the cultivar Mundo Novo IAC 501. The fungicides epoxiconazole, epoxiconazole + pyraclostrobin, tetraconazole, ciproconazole, copper oxychloride, azoxystrobin and carbendazim were applied to the leaves of coffee seedlings, and ciproconazole + tiametoxam, triadimenol + dissulfotom, and triadimenol were applied to the seedlings substrate. Controls were also included in all experiments. The seedlings were inoculated with suspensions prepared with a mixture of five C. coffeicola isolates (3-4 conidia/mL). The incidence and severity of the disease were evaluated 20 to 56 days after the inoculations. With the exception of copper oxychloride, all products were efficient for the control of brown eye spot. The triazoles, with the exception of tetraconazole, showed reversible phytotoxic effects. Ciproconazole + tiametoxam, epoxiconazole + pyraclostrobin and carbendazim had the highest residual effects and maintained small levels of the disease until 56 days after their application. The triazoles used for the control of coffee rust are also effective for the control of brown eye spot.摘要 三唑类杀菌剂（Triazole fungicides）及其与杀虫剂的复配制剂，通常用于防治咖啡作物上的咖啡锈病与潜叶蝇。本研究针对该作物另一重要病害——由咖啡尾孢菌（Cercospora coffeicola）引发的褐斑病，评估了上述药剂的防治效果。本研究采用品种为Mundo Novo IAC 501的咖啡幼苗，在温室中开展了3组试验。供试药剂包括叶面喷施的环氧菌唑（epoxiconazole）、环氧菌唑+吡唑醚菌酯（epoxiconazole + pyraclostrobin）、特菌唑（tetraconazole）、环丙唑醇（ciproconazole）、氧氯化铜（copper oxychloride）、嘧菌酯（azoxystrobin）与多菌灵（carbendazim），以及施用于幼苗育苗基质的环丙唑醇+噻虫嗪（ciproconazole + tiametoxam）、三唑醇+dissulfotom（triadimenol + dissulfotom）与单剂三唑醇（triadimenol）；所有试验均设置对照组。采用由5株咖啡尾孢菌分离物混合制备的孢子悬浮液（浓度为3~4个分生孢子/mL）对幼苗进行接种，于接种后20至56天评估病害的发病率与病情严重度。结果显示，除氧氯化铜外，其余供试药剂均对褐斑病具有显著防治效果；除特菌唑外，其余三唑类药剂均表现出可逆性药害效应。其中，环丙唑醇+噻虫嗪、环氧菌唑+吡唑醚菌酯以及多菌灵的持效性最强，施药后56天仍可将病害维持在较低水平。原本用于防治咖啡锈病的三唑类杀菌剂，同样对褐斑病具有良好防治效果。