Trichoderma aggressivum in mushrooms

Trichoderma aggressivum can ravage crops very quickly. Read these pages to learn what it is and how to act when you see the warning signs.

Originally authored by Mairéad Kilpatrick (Agri-Food and Biosciences Institute) and Caoimhe Fleming-Archibald and Helen Grogan (Teagasc).

About Trichoderma aggressivum

Trichoderma aggressivum is a disease that causes a fast-growing green mould to form in mushroom crops. It can devastate whole crops at a time. It thrives in the conditions necessary for farming mushrooms (e.g. warm temperatures, high relative humidity, darkness in spawn run), taking over the nutrients and space meant for mushroom development.

Infection can occur at compost facilities, growing facilities, during transportation or in filling/emptying operations. You’ll need to follow stringent hygiene measures to prevent and control the effects of the disease.

Symptoms and biology

There are several symptoms to note for Trichoderma aggressivum, but it’s hard to spot the early signs. It’s important to know what the disease looks like in its different stages so that you can deal with infection quickly.

Learn about the symptoms


Trichoderma aggressivum moves rapidly through mushroom crops, so constant monitoring is key. Find out what kind of testing is available and the best site locations to carry out tests.

Find out more


Following a set of strict hygiene measures is the best disease management strategy for mushroom diseases, including the rapidly spreading Trichoderma aggressivum. Read our findings on general best practices, plus specific recommendations on looking after hygiene in key areas of mushroom production.

More about disease control

Useful links

Download the full factsheet: Understanding Trichoderma aggressivum in Bulk Phase 3 compost

Read about the research and information resulting from the MushTV project

Mushroom Virus X

Brown Cap Mushroom Virus

Fungal diseases in mushrooms

Images are courtesy and copyright of: Mairead Kilpatrick (AFBI), Johan Baars (C4C Holding), Piet Liempens (Hooymans Compost BV), Brendan Burns (Sylvan) and Roland Mumm (Wageningen UR)

© John Peeters

An example of the visible green spores /  "competitor mould" caused by Trichoderma aggressivum