Grape powdery mildew caused by Erysiphe necator is a limiting factor in grape production. In order to develop effective management strategies, the factors influencing the survival of the fungus need to be identified and characterized accordingly. For this purpose, we focused on the effect of weather conditions during overwintering on the survival and viability of ascospores. In spring 2017 and 2018, grape leaf litter and bark samples were collected and examined to determine the density of chasmothecia and the viability of ascospores in various Austrian vine growing regions. There were obvious differences in the amounts of chasmothecia between both years and all examined vineyards. Lower quantities of chasmothecia were detected on the exfoliating bark compared to leaf litter, with up to 37% of chasmothecia containing viable ascospores. In comparison, chasmothecia from leaf litter showed a lower viability (up to 5%). The number of viable ascospores per head of vine ranged from 0 to 351 and from 0 to 251 in 2017 and 2018, respectively, and showed partly a strong variation within one location in both years. The infectivity of ascospores on detached leaves was confirmed. In a survival experiment, chasmothecia, when incubated at 7 °C, released more viable ascospores than chasmothecia incubated at 17 °C. After an incubation period of 30 weeks, only chasmothecia stored at the lower temperature contained viable ascospores. However, the mean temperature differences of 0.1 to 1.2 °C during the period of formation of chasmothecia to bud break in both years and six investigated areas did not explain differences in the viability of the ascospores. Differences in vineyard management seem to be of particular importance here.

引起葡萄白粉病白粉病NE CA TOR是葡萄产量的限制因素。为了制定有效的管理策略，需要识别和表征影响真菌存活的因素。为此，我们集中研究了越冬期间天气状况对子囊孢子存活和生存力的影响。在2017年春季和2018年春季，收集并检查了葡萄叶凋落物和树皮样本，以确定奥地利各葡萄藤生长区的覆膜厚度和子囊孢子的活力。两年间和所有检查过的葡萄园之间的覆膜数量明显不同。与叶凋落物相比，在剥落的树皮上检出的樟脑子囊数量较少，高达37％的樟脑子囊含有活的子囊孢子。相比下，叶凋落物的覆膜残存显示较低的生存力（最高5％）。在2017年和2018年，每头葡萄藤的存活子囊孢数量分别为0至351和0至251，并且在这两年中在一个地点的一部分都显示出很大的变化。确认了子囊孢对离体叶片的感染性。在生存实验中，厚皮动物在7°C下孵育时释放的活子囊孢子比在17°C下培养的薄壳菌释放更多的子囊孢子。在30周的潜伏期后，只有在较低温度下储存的鳞皮动物才含有活的子囊孢子。然而，在这两个年份和六个调查区域中，在软化到芽破裂期间，平均温度差为0.1到1.2°C，这不能解释子囊孢子的活力差异。