Plant guide:ð Pumpkin
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Fungal
Powdery Mildew on Pumpkin Leaves
Commonly affects: Cucurbita pepo, C. maxima, C. moschata (Pumpkin)
A white powdery coating spreads across leaf surfaces and stems, starting as small circular patches that merge into larger areas. Heavily affected leaves yellow, dry out, and die back, reducing the plant's ability to size up fruit.
Potential Causes
- 1Podosphaera xanthii or Erysiphe cichoracearum fungi, extremely common on all Cucurbita species
- 2Dense canopy and humid conditions late in the season
- 3Stress from drought or nutrient deficiency increasing susceptibility
Solution Steps
- 1Remove and destroy heavily affected leaves to reduce spore load, but avoid removing so much foliage that fruit is left unshaded.
- 2Apply a sulphur or potassium bicarbonate fungicide at the first sign of white patches.
- 3Improve airflow by thinning overcrowded vines where practical.
- 4Water at the base rather than overhead to keep foliage drier.
Prevention Tip
Powdery mildew is nearly universal on pumpkins by late season â choosing resistant varieties and staying ahead with early sulphur applications matters more than trying to prevent it entirely.
