Troubleshooting
Two batches can show the same symptom for opposite reasons. Naming a cause quickly is the fastest way to fix the wrong thing and lose the next batch as well.
- By the end you can describe a symptom by stage, pattern and recent change.
- By the end you can list competing causes instead of one favourite.
- By the end you can choose the next measurement before any corrective action.
From symptom to cause
A first look, not a diagnosis. Source: ICAR-DMR manual and disease bulletin.
| What you see | Likely cause | First step |
|---|---|---|
| Long stems, small caps | CO₂ too high (above about 1,500 ppm) | More fresh air |
| Green patches on compost | Trichoderma; low pH or leftover ammonia | Isolate, remove; check next batch |
| No pins after casing | Room not aired and cooled | 16 to 18 °C, ventilate |
| Brown sunken spots on caps | Bacterial blotch; wet caps | Dry the surface, humidity under 85% |
| White wet lumps | Wet bubble from casing | Salt, remove; steam next casing |
| Small flies | Sciarid or phorid flies | Screens, light traps, hygiene |
Read numerical examples with their source, method and crop context. They are not universal operating instructions. Historical prices are not current quotations.
Release with evidence
- Notice
- The batch record brings measurements and observations together.
- Understand
- The calendar alone cannot prove compost is ready for spawning.
- Try it
- Hold unresolved batches for a competent release assessment.
01Describe before you diagnose
Three facts come before any cause. Which stage is this: pre-wetting, Phase I, Phase II, or after release? What is the pattern: the whole mass, one end, the top layer, or the zone beside the door? And what changed: a new straw lot, a different manure supplier, unseasonal rain, a fan that was repaired last week.
Write those three down while the batch is in front of you. A symptom described only as compost is bad cannot be investigated next month, and most compost problems are only understood by comparing several batches.
02List competing causes
Take a heap that will not heat. DMR reports that below 1.5 percent nitrogen the material is not properly fermented and the heap may not pass 55 to 60 °C, and it sets a minimum base batch of 300 kg because small heaps lose heat too fast. The heap may also be too wet and airless, or genuinely too dry.
Each of those causes predicts something else you can check. Low nitrogen means the formulation record will show it. Too wet means leachate at the base and a sour smell. Too small means the outside is cool but the very core is warm. Go and look for what you should not find.
- Nitrogen too low
- Too wet and airless
- Batch too small
- Too dry
03Let the numbers name the domain
Several Indian figures act as boundaries, and crossing one points at a domain. Compost above 72 percent moisture cannot aerate properly, turns airless and invites brown and white plaster moulds. NHB links compost below 64 percent, under wet casing, to weeper mushrooms.
Outside pH 7.2 to 7.8 the mycelium slows and white plaster mould may invade. Above 60 °C at pasteurisation DMR warns that the useful thermophilic fungi die and olive green mould follows. Ink caps and Oedocephalum point back at ammonia and nitrogen. The symptom does not prove the cause, but it tells you which measurement to take next.
04Measure next, do not spray next
Compost problems are process problems. No spray corrects moisture, pH, nitrogen or air distribution, and anything applied on a mushroom farm must be checked against its current label approval and state rules before use, not chosen from an old note book.
So the next step after a diagnosis is a measurement, not a chemical. Change one thing in the limiting domain, record what you changed and why, then look for the response in the same measurement. If the response does not come, your cause was wrong and the record you kept is what lets you say so.
Run one structured investigation
- Write the symptom as stage, pattern and what changed recently.
- List three causes that could each produce that exact symptom.
- For each cause, write what you would expect to find if it were true.
- Take that measurement first, then change one thing and watch it.
Write in your farm diary: Symptom description, the competing causes, the evidence found and missing, the change made and the response.
Mistakes that cost a crop
- Naming one cause immediately, then fixing it every batch whether or not it was there.
- Changing three things at once, so no response can be linked to any of them.
- Reaching for a chemical for what is a moisture, nitrogen or airflow problem.
Check yourself
Three questions, instant answersA heap will not heat. The first step is to:
DMR sets a minimum base batch of:
Negative evidence means:
An editorial self-check, not a certificate. Answers are not stored, not even on this device.
Words used in this lesson
- Pattern
- Where a symptom appears: whole mass, one end, top layer or one zone.
- Negative evidence
- A sign that a suspected cause would produce, which you cannot find.
- Limiting domain
- The one part of the process that is actually holding the batch back.
References & further reading
A lesson cannot replace batch measurements or plant-specific procedures.
Open current reference