Penicillium chrysogenum is a beneficial fungus whose Latin name means “painter’s brush”, after the shape of the branched hyphae bearing rows of black/grey spores. The white hyphae grow first, after which the black/grey spores turn the whole organism grey. Penicillin, an antibiotic made by this fungus, is named after it.

The Penicillium genus consists of many species. They all have a similar structure but with different specific shapes and properties. In horticulture, the fungus can be harmful but it can also simply be present without causing any harm. When conditions in the greenhouse are right – high humidity and warm temperatures – the fungus thrives and spores float in the greenhouse air. The tendency to use less energy and fewer crop protection products in all crops is causing the concentration of fungal spores to rise, which in turn increases the risk of infection.

The fungus can be controlled by avoiding constantly high humidity and condensation on the fruit or crop, avoiding damaged and cracked fruits, and reducing the infection pressure in the greenhouse by clearing up residues of leaves, crop and soil.

Text and images: Groen Agro Control.