Downy mildew of rose
and the germ tubes infect the plants either through the stomata or directly by penetrating the cuticula. For germination free water is required. For most [...] mildews, the optimum temperature is around 15 °C. The closer the temperature is to these 15 °C , the shorter the leaf wetness period that is required for germination [...] Inside the plant, the pathogens produce haustoria, small organs with which the pathogen can take up nutrients from the living plant cells. The pathogens