Shirley Andrew M, Vallad Gary E, Dufault Nicholas, Raid Richard, Quesada-Ocampo Lina
University of Florida, Department of Plant Pathology, Gulf Coast Research and Education Center, Wimauma, FL 33598.
Department of Plant Pathology, University of Florida, Gainesville, FL 32611.
Plant Dis. 2022 Apr;106(4):1167-1174. doi: 10.1094/PDIS-03-21-0507-RE. Epub 2022 Mar 23.
Cucurbit production in Florida is impacted by downy mildew on a yearly basis. Cucurbit downy mildew (CDM), caused by , is one of the most devastating cucurbit diseases and can lead to complete yield loss. Nearly continuous production of cucurbits occurs temporally throughout Florida, which puts extensive pressure on the pathogen population to select for individuals that are resistant to fungicides in use labeled for CDM. Loss of efficacy as a result of fungicide resistance developing is becoming a major concern for Florida cucurbit growers who rely on these products to manage CDM. This study was established to evaluate the field activity of 11 utilized fungicides by determining their duration of activity when applied at various intervals for the management of CDM in cucumber under Florida field conditions. By comparing levels of percent CDM control and area under the disease progress curve values, the fungicide's duration of field activity was established. Field activities were <1 week for dimethomorph and fluopicolide; 1 week for cymoxanil; 1 to 2 weeks for chlorothalonil and mancozeb; 2 weeks for ethaboxam; 1 to 3 weeks for propamocarb, cyazofamid, and ametoctradin + dimethomorph; and 2 to 4 weeks for oxathiapiprolin and fluazinam. Knowledge of duration of field activity can potentially improve the development of CDM management programs and slow the resistance selection.
佛罗里达州的葫芦科作物生产每年都受到霜霉病的影响。由[病原菌名称缺失]引起的葫芦科霜霉病（CDM）是最具毁灭性的葫芦科病害之一，可导致产量完全损失。在佛罗里达州，葫芦科作物几乎全年都在持续种植，这给病原菌群体带来了巨大压力，促使其筛选出对用于防治CDM的标签上标明的杀菌剂具有抗性的个体。由于杀菌剂抗性的产生而导致药效丧失，正成为依赖这些产品来防治CDM的佛罗里达州葫芦科作物种植者的一大担忧。本研究旨在通过确定11种常用杀菌剂在佛罗里达州田间条件下以不同间隔施用于黄瓜防治CDM时的活性持续时间，来评估它们在田间的活性。通过比较CDM防治百分比水平和病害进展曲线下面积值，确定了杀菌剂的田间活性持续时间。烯酰吗啉和氟吡菌胺的田间活性<1周；霜脲氰为1周；百菌清和代森锰锌为1至2周；乙嘧酚磺酸酯为2周；丙酰胺霜霉威、氰霜唑和嘧菌酯 + 烯酰吗啉为1至3周；恶唑菌酮和氟啶胺为2至4周。了解田间活性持续时间可能会改善CDM管理方案的制定，并减缓抗性选择。
