Downy mildew of rose
wetness period that is required for germination. Inside the plant, the pathogens produce haustoria, small organs with which the pathogen can take up nutrients [...] The pathogens are dispersed by air, water and tools. Some species, for example Hyaloperonospora parasitica and Peronospora farinose are assumed to be s [...] the seed). Optimum temperature for germination, infection and sporulation is relatively low, in general between 10 and 20 °C. Late in the season new o