Describe the change
Undifferentiated dry masses when young tissue is affected.
Fungal diseases
Dry bubble
An infection whose appearance changes with the age of the mushroom when it is attacked. A distorted pin and a spotted mature cap can belong to the same disease.
Organism / cause: Lecanicillium fungicola; older literature: Verticillium fungicola
Where this evidence applies: Principally cultivated Agaricus; do not transfer the diagnosis to every malformed mushroom.
Reference image only. These are published study examples, not photographs of your crop or claims about an Indian outbreak.
Picture → observation → next check
Read the picture with the evidence
Keep another explanation open
Wet bubble, which can also distort developing mushrooms.
Collect one useful piece of evidence
Map the first patch against the casing lot and watering route.
A visual match is only a starting point. A specialist distinguishes the symptom pattern and examines an appropriate sample; a picture alone does not identify the fungus.
01 · Observe
What you may see
- Undifferentiated dry masses when young tissue is affected.
- Split or bent stems and local grey-brown cap lesions in later infections.
02 · Compare
What can look similar
- Wet bubble, which can also distort developing mushrooms.
- Bacterial spots, mechanical injuries and developmental disorders.
How it may arise or move
Spores can move with splashed water, contaminated equipment, people and insects; contaminated casing is an important investigation point.
03 · Check
Collect evidence before changing the crop
- Map the first patch against the casing lot and watering route.
- Record crop stage and whether caps, stems or entire pins are affected.
What confirmation needs: A specialist distinguishes the symptom pattern and examines an appropriate sample; a picture alone does not identify the fungus.
Use the field record and sampling checklist →04 · Respond
What to do next
- Mark and leave suspected dry bubbles undisturbed. Do not pick them out as a first response.
- Have a trained supervisor plan containment before watering or harvesting nearby.
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 casing and clean equipment from dust, floors and spent crops.
- Work from clean rooms towards affected rooms and review fly exclusion.
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
Established Agaricus disease; archived extension instructions supplement the fungal-disease review.
- Fungal diseases in mushrooms: dry bubble disease ↗
AHDB archive · Undated archived guidance
Used for: Symptom forms, handling risks and containment principles.
Limit: Archived UK guidance; not current Indian product authorisation.
- Control of Fungal Diseases in Mushroom Crops while Dealing with Fungicide Resistance: A Review ↗
Gea et al., Microorganisms 9:585 · 2021
Used for: Dry bubble, wet bubble, cobweb and green mould; Figure 1 reference photographs.
Limit: Review, not a local diagnosis. Fungicide approvals and resistance vary by country. Photographs retained with CC BY attribution.
Compare related explanations
Fungal diseases
Wet bubble
A disease of developing mushroom tissue, often producing swollen, disorganised masses rather than a normal cap and stem.
Agaricus disease; the two names occur in different publications.
Signs, checks & response →Fungal diseases
Cobweb disease
Spreading surface growth can overrun casing and fruit bodies. The important clue is progression across the crop, not simply white colour.
Strong Agaricus evidence; additional cultivated hosts are documented in Korean studies. Susceptibility varies with isolate and host.
Signs, checks & response →Bacterial diseases
Brown bacterial blotch in button mushrooms
Persistent surface wetness can favour bacterial blotch. Managing cap drying means balancing the crop environment, not simply drying the entire room.
Agaricus caps; a brown spot does not establish bacterial identity.
Signs, checks & response →