Center for Crop Health, University of Southern Queensland, Toowoomba, Queensland 4350, Australia.
Departamento de Fitopatologia, Universidade Federal de Viçosa, Viçosa MG 36570-900 Brazil.
Plant Dis. 2022 Mar;106(3):918-924. doi: 10.1094/PDIS-06-21-1256-RE. Epub 2022 Mar 10.
Powdery mildew (PM), caused by two fungal species, and , is a yield-limiting foliar disease commonly found in mungbean ( cropping areas of the eastern region of Australia. Effective control of the disease relies largely on fungicide applications, mainly of the triazole group. Uncertainty in the current fungicide spray schedule recommendations, which advise commencing with a spray at the first signs of PM, prompted this study to evaluate PM severity and crop yield data obtained from fungicide trials, which also tested spray schedules starting before (early) or after (late) first signs, applied singly or combined with a follow-up spray. A meta-analytic approach was used to obtain mean differences of the PM severity and crop yield between plots sprayed with specific triazole-based spray schedules and nontreated plots. From 26 trials, 14 trials and 15 trials met the criteria for inclusion in PM severity and yield analyses, respectively. The schedule with the first spray starting at first sign, with a follow-up spray 14 days later, resulted in significantly lower disease severity compared with all other schedules. However, the yield protected was only numerically higher and not statistically different compared with single-spray at first sign, single-spray late, or two-spray starting late. PM severity and yield in the early sprayed plots did not differ from the nontreated plots. These findings support the current recommendations and provide additional evidence that yields are still protected when delaying the first spray up to a week after disease onset. They also suggest that additional sprays may not always be necessary, thus reducing direct fungicide costs, indirect costs related to fungicide insensitivity, and potential adverse effects to the environment.
白粉病（PM）由两种真菌物种 和 引起，是一种常见于绿豆（ 在澳大利亚东部地区的作物种植区。叶面疾病。该病的有效控制主要依赖于杀菌剂的应用，主要是三唑类。目前杀菌剂喷雾时间表的建议存在不确定性，建议在首次出现 PM 症状时开始喷雾，这促使本研究评估了从杀菌剂试验中获得的 PM 严重程度和作物产量数据，这些试验还测试了在首次出现症状之前（早期）或之后（晚期）开始的喷雾计划，单独或与后续喷雾一起应用。采用荟萃分析方法获得了用特定三唑类喷雾计划喷雾的地块与未处理地块之间 PM 严重程度和作物产量的平均差异。在 26 次试验中，有 14 次试验和 15 次试验分别符合纳入 PM 严重程度和产量分析的标准。首次喷雾在首次出现症状时开始，14 天后进行后续喷雾的计划与所有其他计划相比，导致疾病严重程度显著降低。然而，与首次出现症状时的单次喷雾、晚期单次喷雾或晚期两次喷雾相比，受保护的产量仅在数值上较高，在统计学上没有差异。早期喷雾地块的 PM 严重程度和产量与未处理地块没有差异。这些发现支持当前的建议，并提供了额外的证据表明，在疾病发生后延迟首次喷雾长达一周仍能保护产量。它们还表明，不一定总是需要额外的喷雾，从而降低了直接杀菌剂成本、与杀菌剂不敏感性相关的间接成本以及对环境的潜在不利影响。
