Definition of downy mildew in US English:

downy mildew


  • Mildew on a plant which is marked by a whitish down composed of spore-forming hyphae, penetrating more deeply into the plant than powdery mildew.

    Family Peronosporaceae, subdivision Mastigomycotina

    • ‘Chocolate spot rust and downy mildew have all increased in winter beans during the last week.’
    • ‘They showed me some downy mildew in the two year-old vines, and explained that they were trying to decide whether or not to treat it with phosphorous acid.’
    • ‘However, if copper is applied for downy mildew control, it will provide some protection against powdery mildew.’
    • ‘Eastern growers must also contend with humidity-loving black rot, botrytis, downy mildew, and phomopsis.’
    • ‘Common onion diseases include damping off, botrytis leaf blight, downy mildew, and bacterial blight.’
    • ‘Another kind of mildew, downy mildew, causes round, dark purple spots with yellow edges.’
    • ‘Climatic conditions are conducive to the development of several major grape diseases, including: black rot, downy mildew and powdery mildew.’
    • ‘This is in contrast to most other grape pathogens, such as black rot and downy mildew, that require free water on the plant surface before the spores can germinate and infect.’
    • ‘So it's very good news that scientists have found genetic markers that easily identify broccoli varieties with natural resistance to downy mildew.’
    • ‘Crazy top or downy mildew also was reported in a few fields in central Kansas.’
    • ‘On cultivars highly susceptible to downy mildew and powdery mildew, some post harvest application may be required to protect foliage and prevent premature defoliation.’
    • ‘Both powdery mildew and downy mildew often infect squash plants as autumn nights grow cooler and dew keeps the foliage moist through the night.’
    • ‘While there is an absence of greenfly, it's a bad year for downy mildew in Ireland and my roses are also afflicted with black spot and rust, these three being the most serious diseases roses are prone to.’
    • ‘Before the accidental introduction of this disease, farmers spent considerable amounts to control another fungal disease, downy mildew.’
    • ‘Although we emphasize the use of fungicides for downy mildew control after bloom, early season fungicide applications appear to provide some level of control later in the season.’
    • ‘A site that provides for maximum air drainage which promotes faster drying of foliage can substantially reduce the risk of black rot and downy mildew.’
    • ‘We've all seen rose leaves with black spot or downy mildew.’
    • ‘The more common ones are powdery mildew, blackspot, downy mildew and rust.’
    • ‘Roses are also likely to require the use of fungicidal sprays to rid them of diseases such as downy mildew.’