Department of Plant and Environmental Sciences, Clemson University, Coastal Research and Education Center, Charleston, SC 29414.
Phytopathology. 2022 Aug;112(8):1651-1658. doi: 10.1094/PHYTO-10-21-0432-R. Epub 2022 Jul 6.
A nationwide, quantitative synthesis of fungicide efficacy data on management of cucurbit downy mildew (CDM) caused by is needed to broadly evaluate fungicide performance. Three-level meta-analysis, three-level meta-regression, and network meta-analyses were conducted on data from 46 cucumber () CDM fungicide efficacy studies conducted in the eastern United States retrieved from published between 2009 and 2018. Three response variables were examined in each analysis: disease severity, marketable yield, and total yield, from which percent disease control and percent yield return compared with nontreated controls was calculated. Moderator variables used in the three-level meta-analysis or three-level meta-regression included year, disease pressure, number of fungicide applications, and slicing or pickling cucumbers. In the network meta-analysis, fungicides were grouped by common combinations of Fungicide Resistance Action Committee Codes and modes of action. Overall, fungicides significantly ( < 0.001) reduced disease severity and increased marketable and total yields, resulting in a mean 54.0% disease control and 61.9% marketable and 73.3% total yield return. Subgroup differences were observed for several fungicide applications, control plot disease severity, and cucumber type for marketable yield. Based on the meta-regression analysis for disease severity by year, fungicide efficacy has been decreasing from 2009 to 2018, potentially indicating broad development of fungicide resistance over time. Treatments containing quinone inside inhibitors, pyridinylmethyl-benzamides, and protectants and treatments containing oxysterol binding protein inhibitors and protectants most effectively reduced disease severity. The most effective fungicide combinations for disease control did not always result in the highest yield return.
需要对美国东部地区的 46 项黄瓜霜霉病（CDM）防治药剂田间药效试验数据进行全国范围的定量综合分析，以全面评估杀菌剂的防治效果。本研究对 2009 年至 2018 年间发表的 46 项田间药效试验数据进行了三级荟萃分析、三级元回归分析和网络荟萃分析。每个分析都检查了 3 个反应变量：病情严重度、商品产量和总产量，从中计算了与未处理对照相比的病害防治百分率和产量返还百分率。三级元回归分析或三级元回归分析中使用的调节变量包括年份、病情压力、施药次数以及切片黄瓜或腌制黄瓜。在网络荟萃分析中，杀菌剂按杀菌剂抗性行动委员会（Fungicide Resistance Action Committee，Fungicide Resistance Committee，FRC）代码和作用方式的常见组合进行分组。总体而言，杀菌剂能显著降低病情严重度（<0.001），增加商品产量和总产量，导致平均 54.0%的病害防治率和 61.9%的商品产量返还率和 73.3%的总产量返还率。在商品产量方面，施药次数、对照小区病情严重度和黄瓜类型的不同导致了一些杀菌剂的分组差异。基于对各年份病情严重度的元回归分析，杀菌剂的防治效果从 2009 年到 2018 年呈下降趋势，这可能表明杀菌剂抗性随时间的广泛发展。含有醌类抑制剂、吡啶基甲基苯甲酰胺类和保护剂的处理以及含有甾醇结合蛋白抑制剂和保护剂的处理能最有效地降低病情严重度。在防治病害方面最有效的杀菌剂组合并不总是能带来最高的产量返还率。
