Aureobasidium

Aureobasidium is a genus of yeast-like fungi, with Aureobasidium pullulans being the most widespread species. It acts as an opportunistic plant pathogen, frequently associated with the development of black mold or sooty blotch on the surface of various fruits and leaves.

This fungus primarily affects a wide range of fruit-bearing plants, including apples, pears, grapes, and various vegetables. It thrives on the plant surface, particularly where sugars are present, such as honeydew secreted by aphids or damage caused by environmental factors, turning these spots into infection sites.

The disease symptoms typically manifest as dark, discolored lesions or black fungal mats on the surface of skins and leaves. In severe cases, the cosmetic damage caused by the black mold significantly reduces the market value of the harvest, and deep infections can lead to tissue decay during storage.

Environmental conditions play a critical role in its proliferation, specifically high humidity, frequent rain, and moderate temperatures. The spores are easily dispersed by wind, water splashes, and insect vectors, allowing the fungus to spread rapidly throughout an orchard or a greenhouse environment.

Management and prevention strategies focus on cultural practices to minimize humidity and surface wetness, such as proper pruning for airflow and regular removal of infected plant debris. Chemical control using preventive fungicides, particularly copper-based formulations, is recommended to manage populations during high-risk seasons.