Grape downy mildew
humidity), the disease is often well-established before it can be visually detected in the field. Leaf symptoms Yellowish to light-green oil spots on the upper [...] forming haustoria to parasitize mesophyll cells. The latent period (the time from infection to visible symptoms) ranges from 4 to 21 days, depending on [...] In spring, oospore germination is triggered when temperatures reach 10°C in the presence of soil moisture, leading to the formation of macrosporangia that