Describe the change
Separate powdery colonies in stored ingredients, spawn or bags.
Competitor moulds
Aspergillus, Penicillium and unidentified green moulds
Green, blue-green or dark growth is not automatically Trichoderma. Neither harmlessness nor toxin production can be established from its colour.
Organism / cause: Several genera; laboratory identification required
Where this evidence applies: Raw-material, spawn, substrate and storage contamination differential across production systems.
Picture → observation → next check
A visual guide to your observations
- Casing layer
For crops that use casing, trace storage, handling and the casing lot separately from the compost.
- Compost below
Compare the compost lot and preparation history. White growth is not, by itself, proof of either purity or contamination.
- Straw bag
Record treatment, cooling, spawning and the first affected position through the intact bag.
- Wood-substrate block
Check the filter, seal and batch history without opening suspect material. Normal block appearance depends on crop and stage.
Keep another explanation open
Trichoderma and other sporulating fungi.
Collect one useful piece of evidence
Trace ingredient storage moisture and age.
A visual match is only a starting point. Organism identity and food-safety acceptability are different questions; each may require specific testing.
01 · Observe
What you may see
- Separate powdery colonies in stored ingredients, spawn or bags.
- Discolouration associated with stalled colonisation or deteriorating material.
No verified reusable diagnostic photograph is included for this entry. The illustration above explains observation context, not a confirmed disease specimen. Consult the original source figures where available.
02 · Compare
What can look similar
- Trichoderma and other sporulating fungi.
- Pigments or debris without living mould.
How it may arise or move
Dust, stored ingredients, damp surfaces and handling are plausible routes to investigate rather than assume.
03 · Check
Collect evidence before changing the crop
- Trace ingredient storage moisture and age.
- Record whether growth was visible before treatment or developed after inoculation.
What confirmation needs: Organism identity and food-safety acceptability are different questions; each may require specific testing.
Use the field record and sampling checklist →04 · Respond
What to do next
- Hold contaminated ingredients or produce out of the food chain pending qualified assessment.
- Do not sniff, taste or dry-brush the colony.
These are investigation and containment steps, not a guaranteed cure. Do not eat, sell or distribute suspect material on the strength of a visual match. Do not culture unknown contaminants or experiment with pesticides in a growing room.
05 · Learn
Reduce recurrence
- Protect dry ingredients from water ingress and pests.
- Use lot identification and stock rotation; clean spills without raising dust.
After intervention, compare new affected units, crop condition and inspection results against the same recorded baseline. A lack of visible growth does not, by itself, verify decontamination or food safety.
Read the stage-by-stage prevention plan →Evidence & sources
Historical competitor categories combined with exposure-control and exclusion principles; no host-wide pathogenicity claim.
- Diseases and Competitor Moulds of Mushrooms and their Management ↗
ICAR–National Research Centre for Mushroom, Solan (now DMR) · 2007
Used for: Historical Indian register of competitor names and abiotic disorders; printed pages 2–43 and 65–69.
Limit: Older names and treatments. Used as a coverage checklist, not a current pesticide label or an image-reuse licence.
- IPM in Mushroom Production: Exclusion Techniques for Pest Control ↗
Penn State Extension · Undated page
Used for: Separation of clean and older crops, tools and material routes.
Limit: Adapt the workflow to actual building, worker safety and ventilation needs.
- Controlling exposure to dust and bioaerosols on farms growing common commercial mushrooms ↗
UK Health and Safety Executive / HDC · 2011
Used for: Worker exposure controls and respiratory-risk assessment.
Limit: Agaricus-focused occupational guidance, not diagnosis or treatment of a person.
Compare related explanations
Fungal diseases
Green mould in button compost
A competitive or pathogenic fungus can occupy compost that should be colonised by the mushroom. Green spores may appear after an initially white phase.
Composted Agaricus substrate. Not every green colony is the aggressive epidemic organism.
Signs, checks & response →Fungal diseases
Green mould in oyster and other bags
A bag can contain competing mould before green colour is visible. Oyster-associated Trichoderma species differ from the main button-mushroom epidemic species.
Detailed pathogen evidence exists for Pleurotus; the other listed crops have published green-mould host reports, not a shared diagnosis.
Signs, checks & response →Food & worker safety
Foodborne contamination is not the same as crop disease
A healthy-looking mushroom is not proof of food safety. A crop-disease photo guide cannot detect Listeria, Salmonella or unacceptable residues.
All edible-mushroom food chains; enoki outbreak evidence is a specific example, not a claim about every crop.
Signs, checks & response →