Powdery mildew is a fungal disease caused by various species of fungi, primarily from the Erysiphaceae family. The most common species affecting a wide range of plants are:
- Erysiphe cichoracearum: Affects many crops and ornamental plants.
- Sphaerotheca pannosa: Often found on roses and other flowering plants.
- Podosphaera leucotricha: Commonly affects apple and pear trees.
Powdery mildew is characterized by white, powdery spots or patches on the leaves, stems, and buds of infected plants. It thrives in warm, dry conditions and can spread quickly. Control methods include improving air circulation around plants, using resistant cultivars, and applying fungicides when necessary.