The symptoms appear on leaves, shoots, buds, thorns, peduncles and flowers as a powdery, whitish growth (mycelium, conidiophores and spores) of the mildew fungus. Severe mildew damage reduces leaf growth, aesthetic value of plants, photosynthetic efficiency and thereby plant growth. Plants can be severely stunted if they are heavily infected early in the growing season. When the environmental conditions are favourable, the affected leaves may fall prematurely.
Pruning infected shoots, greenhouse sanitation, adequate ventilation and fungicide applications.
Powdery Mildew Life Cycle