Describe the change
Yellow growth or deposits associated with weak mushroom mycelium.
Competitor moulds
Yellow mould / tikki disease
An Indian seasonal-production problem worth investigating when yellow colonies accompany poor compost colonisation.
Organism / cause: Myceliophthora lutea and Sepedonium species in Indian reports
Where this evidence applies: Agaricus compost; “yellow mould” is a group description, not one confirmed organism.
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
Normal compost colour, yellow metabolites and other moulds.
Collect one useful piece of evidence
Compare affected and unaffected compost lots.
A visual match is only a starting point. Colour is insufficient to distinguish the organisms included under this historical label.
01 · Observe
What you may see
- Yellow growth or deposits associated with weak mushroom mycelium.
- A batch pattern rather than isolated cap bruising.
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
- Normal compost colour, yellow metabolites and other moulds.
- Poor crop growth without a fungal competitor.
How it may arise or move
A compost-associated investigation should include preparation, conditioning, storage and filling records.
03 · Check
Collect evidence before changing the crop
- Compare affected and unaffected compost lots.
- Record where yellow material occurs without breaking up dusty substrate.
What confirmation needs: Colour is insufficient to distinguish the organisms included under this historical label.
Use the field record and sampling checklist →04 · Respond
What to do next
- Hold the identity as provisional and contact the compost supplier.
- Ask for diagnostic examination before treating an entire crop.
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
- Verify compost-process records and protect finished compost.
- Keep spent compost away from new material and equipment.
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
Indian research abstract reviewed; not a current treatment protocol.
- Status of Yellow Mould Diseases of White Button Mushroom in Haryana and Its Management ↗
Journal of Mycology and Plant Pathology; ICAR–DMR authors · 2019
Used for: Research abstract identifies Myceliophthora and Sepedonium organisms in seasonal button production.
Limit: Abstract reviewed, not the full study. Experimental crop losses are not predictions for a reader’s farm; no chemistry adopted.
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 →Environmental disorders
Ammonia, waterlogging and unsuitable substrate
Poorly colonised substrate can be a process failure before a competitor arrives. Treating the visible late mould may miss the original cause.
Ammonia/conditioning is especially relevant to button compost. Bag substrates use different preparation systems.
Signs, checks & response →