Green mold of mushrooms

Trichoderma aggressivum is a serious fungal pathogen known to cause aggressive green mold disease in cultivated mushrooms. This pathogen belongs to the Hypocreaceae family and is recognized as one of the most economically damaging diseases in the commercial mushroom industry worldwide.

The fungus primarily targets the button mushroom, Agaricus bisporus. It acts as a hyper-parasite and a competitor, rapidly colonizing the compost and casing layer. By secreting enzymes and toxins, it successfully displaces the mushroom mycelium, leading to a complete failure of the crop in infected areas.

Symptoms initially appear as white, fluffy mycelial growth that rapidly turns vibrant green as sporulation occurs. Infected areas show poor mycelial colonization and a distinct, foul, acidic odor. As the infection progresses, the growth of mushroom pins is completely suppressed or produces malformed fruit bodies.

Development and spread of Trichoderma aggressivum are facilitated by high humidity, poor ventilation, and contaminated substrates. The spores are microscopic and extremely resilient, often spread by farm workers, tools, insects, or contaminated casing material. Even small outbreaks can escalate quickly if not contained.

Control strategies are focused on strict sanitation and hygiene practices throughout the entire production cycle. Key measures include:

• Thorough heat treatment (steaming) of mushroom houses.
• Using high-quality, pasteurized compost.
• Limiting access to cultivation areas.
• Rigorous equipment and clothing disinfection.