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    Farming & Crop Protection Downy mildew (cucumber)

    Downy mildew (cucurbits) [Pseudoperonospora cubensis]

    Especially at risk are open-land and hot house cucumbers. Other cucurbit may also become affected. Without treatment, infection of the entire crop may occur within 14 days.

     

    overview

    Downy mildew (cucurbits) - image 1

    Downy mildew (cucurbits) - image 1

    Downy mildew (cucurbits) - image 2

    Downy mildew (cucurbits) - image 3

    Pest Profile

    • Symptoms & Diagnosis

      Occurence

      Downy mildew may occur throughout the entire growing season, however, primarily starting in July. The disease spreads particularly fast on cold nights with dew formation.

      Pattern of damage

      Yellow spots, frequently limited angularly by the leaf veins, appear on the upper side of the leaf. (Picture 1) The brownish spore lawn which is typical for mildew appears on the underside of the leaf (Picture 2). Later on, the plants look burnt (Picture 3).

      Treatment

      Combat

      When symptoms first occur, fungicide must be sprayed immediately. Under glass, a nocturnal dew formation should be prevented by heating.