Strategies for the control of grape powdery mildew, caused by Erysiphe necator, Schw., require consideration of the development of fungicide resistance. We investigated the effect of inoculum reduction by fungicides with low resistance risk (copper oxychloride, potassium bicarbonate, meptyldinocap, wettable sulphur) in the laboratory and as individual post-harvest and bud break treatments. Ascospore viability and release were analysed after a post-harvest treatment and disease incidence and severity of grapes were determined following a bud break treatment. In the laboratory all fungicides reduced the viability (spring 2018 p = 0.008; autumn 2018 p = 0.021; spring 2019 p = 0.010; autumn 2019 p = 0.484) and the release (spring 2018 p = 0.007; autumn 2018 < 0.001; spring 2019 < 0.001) of ascospores, although the decrease was more pronounced in spring compared to autumn. At Krems, the post-harvest field application of copper oxychloride, potassium bicarbonate, meptyldinocap and wettable sulphur in autumn 2017 reduced the percentage of viable chasmothecia significantly (p < 0.001) by 56–74%. In autumn 2018, the tested fungicides had no effect on the percentage of viable chasmothecia (p = 0.129). At Andau, the percentage of viable chasmothecia was only reduced by copper oxychloride (p = 0.029). The amount of viable ascospores was significantly (p = 0.002) lowered after a post-harvest field treatment with the fungicides by 46–70%, whereas for meptyldinocap only a trend could be determined. Disease incidence and severity were not influenced by sulphur applications at bud break (p = 0.689, p = 0.224) and by different levels of chasmothecia (p = 0.104, p = 0.353). A trend in one year, that a high amount of chasmothecia increased the disease incidence, was related to the weather conditions and the duration from the time of first ascosporic infection until flowering. The data indicates the importance of an effective control with fungicides during the pre-flowering stage in years with a long time from primary infection until flowering. Furthermore, this study shows that post-harvest sprays with low risk fungicides can help to reduce the number of fungicide treatments needed for powdery mildew control at the end of the in-season spray program. This measure could be integrated into an environmentally friendly pesticide reduction program for controlling powdery mildew in viticulture.

葡萄白粉病的控制策略，造成葡萄白粉菌, Schw., 需要考虑杀菌剂抗性的发展。我们在实验室中研究了具有低抗性风险的杀菌剂（氯氧化铜、碳酸氢钾、meptyldinocap、可湿性硫磺）以及作为单独的收获后和萌芽处理减少接种量的效果。在收获后处理后分析子囊孢子活力和释放，并在芽破处理后确定葡萄的疾病发生率和严重程度。在实验室中，所有杀菌剂都降低了生存力（2018 年春季 p = 0.008；2018 年秋季 p = 0.021；2019 年春季 p = 0.010；2019 年秋季 p = 0.484）和释放量（2018 年春季 p = 0.007；2018 年秋季< 0.001) 的子囊孢子，尽管与秋季相比，春季减少更为明显。在克雷姆斯，2017 年秋季在收获后田间施用氯氧化铜、碳酸氢钾、meptyldinocap 和可湿性硫磺，显着（p < 0.001）将活绦虫的百分比降低了 56-74%。2018 年秋季，所测试的杀菌剂对活绦虫的百分比没有影响（p = 0.129）。在 Andau，仅使用氯氧化铜（p = 0.029）就可以降低有活力的 chasmothecia 的百分比。在收获后用杀真菌剂进行田间处理后，存活子囊孢子的数量显着降低（p = 0.002）46-70%，而对于 meptyldinocap，只能确定一个趋势。病害发生率和严重程度不受萌芽时硫磺应用（p = 0.689，p = 0.224）和不同水平的绦虫（p = 0.104，p = 0.353）的影响。一年的趋势，大量的chasmothecia增加了发病率，这与天气条件和从第一次子囊孢子感染到开花的持续时间有关。数据表明在开花前阶段使用杀菌剂进行有效控制的重要性，从初次感染到开花的时间很长。此外，这项研究表明，收获后喷洒低风险杀菌剂有助于减少季节性喷洒计划结束时控制白粉病所需的杀菌剂处理次数。该措施可以整合到环境友好的农药减少计划中，以控制葡萄栽培中的白粉病。数据表明在开花前阶段使用杀菌剂进行有效控制的重要性，从初次感染到开花的时间很长。此外，这项研究表明，收获后喷洒低风险杀菌剂有助于减少季节性喷洒计划结束时控制白粉病所需的杀菌剂处理次数。该措施可以整合到环境友好的农药减少计划中，以控制葡萄栽培中的白粉病。数据表明在开花前阶段使用杀菌剂进行有效控制的重要性，从初次感染到开花的时间很长。此外，这项研究表明，收获后喷洒低风险杀菌剂有助于减少季节性喷洒计划结束时控制白粉病所需的杀菌剂处理次数。该措施可以整合到环境友好的农药减少计划中，以控制葡萄栽培中的白粉病。这项研究表明，在收获后喷洒低风险杀菌剂有助于减少季节性喷洒计划结束时控制白粉病所需的杀菌剂处理次数。该措施可以整合到环境友好的农药减少计划中，以控制葡萄栽培中的白粉病。这项研究表明，在收获后喷洒低风险杀菌剂有助于减少季节性喷洒计划结束时控制白粉病所需的杀菌剂处理次数。该措施可以整合到环境友好的农药减少计划中，以控制葡萄栽培中的白粉病。