The increasing needs of humanity for food supply, the need to reduce fertilizer and pesticide use to protect human and environmental health, and the threats of climate change and disease emergence all provide incentives to use microorganisms to promote crop growth and health (Busby et al. 2017; D'Hondt et al. 2021; Toju et al. 2018). One of the challenges currently facing us is discovering and identifying microbial strains or consortia capable of alleviating biotic and abiotic stresses, and integrating them into crop management (Berg et al. 2017; Poudel et al. 2016). Addressing this challenge is crucial in the case of European cultivated grapevine (Vitis vinifera L.) because this emblematic crop is a very heavy user of phytosanitary products (mainly copper, sulfur and synthetic chemical fungicides targeting leaf diseases). Strengthening microbial biocontrol of grapevine leaf diseases by stimulating the microbiota naturally present in vineyards or by inoculating new microorganisms (Bartoli et al. 2020) could reduce viticulture reliance on chemical fungicides. However, this nature-based solution (Maes and Jacobs 2017) will only be effective and sustainable if microbial antagonisms are resilient to microclimatic and climatic variations and associated changes in vine physiology. This is why vine-pathogen-microbiota interactions should be studied under a range of abiotic conditions. Powdery mildew is one of the grapevine leaf diseases for which the use of chemical fungicides must be reduced. It is caused by the ascomycete fungus Erysiphe necator