If white, gray or brown spots appear on the leaves and plant parts of the zucchini, the plant is infected with powdery mildew or powdery mildew. Both are fungal diseases and must be fought immediately, as they can lead to the death of the leaves or the entire plant.
powdery mildew
With powdery mildew, white, mealy spots cover the surfaces of the leaves, but also of the stems and fruits. Eventually the leaves will turn brown and die. Powdery mildew is caused by prolonged drought.
Wrong mildew
Cold, damp weather can lead to downy mildew infestation. You can recognize it by the whitish to brownish, velvety coverings on the underside of the leaf and brown or yellow spots on the upper side.
combat
- Remove affected leaves and plant parts immediately and dispose of in the trash
- Spraying with anti-fungal agents such as Detia's "Plant-Mushroom-Free" or "Fungisan®Rosen- und Gemüse-Filzfrei" from Neudorff
- Garlic or onion infusion against downy mildew
- Spray fresh milk-water mix in a ratio of 1:9, 2-3 times a week
tips and tricks
Many new zucchini breeds are resistant to powdery mildew. These include the varieties "Diamant", "Mastil F1" and "Leila F1".