Plant guide:ð Grapes
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Fungal
Powdery Mildew on Grape Vines
Commonly affects: Vitis vinifera, V. labrusca (Grape)
A white to grey powdery coating spreads across leaves, shoots, and berries, causing distorted growth and cracked, scarred fruit skin in severe cases.
Potential Causes
- 1Erysiphe necator fungus, one of the most common grape diseases worldwide
- 2Warm, dry conditions with high humidity at night â unusually, this mildew doesn't need free water to spread
- 3Dense canopy restricting airflow
Solution Steps
- 1Prune to open up the canopy and improve airflow around clusters
- 2Apply a sulphur-based fungicide starting early in the season as a preventive measure
- 3Remove and destroy heavily affected leaves and shoots
- 4Choose resistant varieties for future plantings in high-pressure areas
Prevention Tip
Unlike most fungal diseases, grape powdery mildew doesn't need rain or high humidity to spread â proactive sulphur applications starting early in the season are standard practice.
