Six 1-year-old, 1 m tall V. cinerea B9 plants were acclimated in a lighted mist chamber (25 °C) 2 days before inoculation. Leaves were spray inoculated with a Preval handheld paint sprayer (Preval, IL, USA) using either a D. ampelina suspension isolated from field-infected vines as described, or sterile water (mock).