Survival and viability of ascospores of Erysiphe necator in Austrian vineyards

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