What to Do When Mushroom Mycelium Shrinks? Causes and Control Methods

Cultivating mushrooms is not difficult, but every step must be carried out strictly. Once there is any oversight, it is very easy for competitor fungi, diseases, or even mycelium shrinkage to appear. For mushrooms, this is “fatal” and will also affect growers' harvests, so let us take a look at the causes of mushroom mycelium shrinkage and the control methods.

1. Too high a temperature causes mycelium burning

During mushroom cultivation, if the air temperature is too high and the compost is relatively thick, and after fermentation the compost temperature has not yet stabilized and dropped, these causes can all lead to mycelium shrinkage.

Control method: The mushroom cultivation period should avoid the high-temperature season, and the compost temperature is best kept below 25°C. Once mycelium shrinkage caused by high temperature is found, the pile should be turned and ventilated immediately, then the moisture of the compost should be readjusted and sowing should be carried out again.

2. Ammonia in the compost causes mycelium shrinkage

When building the pile, many people add too much nitrogen fertilizer, or add nitrogen fertilizer only at a later stage. This causes ammonia to be present in the compost and leads to mycelium shrinkage.

Control method: When planting mushrooms, an appropriate amount of chemical fertilizer such as urea should be added when building the pile, so as to avoid ammonia appearing later. If ammonia has already been found in the compost, open the windows for ventilation in time, turn the material with formaldehyde solution, and sow again once there is no smell of ammonia.

3. The compost is too dry

If the compost is too dry, it can also cause mycelium shrinkage. In addition, when the climate is very dry, after the mycelium germinates and begins feeding on the compost, its growth is very slow.

Control method: A relatively wet layer of rice straw can be spread over the side where the material is taken, generally after soaking it in limewater. In this way, the mycelium can germinate and feed on the compost again. If relatively dry weather is encountered at sowing time, the doors and windows can be closed after three days.

4. The quality of the mushroom spawn is not up to standard

If the spawn is exposed to heat when purchased, the vitality of the mycelium is reduced. It is also possible that the purchased spawn was not planted in time, causing the spawn to age; naturally, growth is then relatively slow and the growth vigor is relatively weak.

Control method: The choice of spawn is very important. Try to choose a suitable compost for cultivating the spawn, and it is best to choose varieties with good germination ability and thick, strong mycelium. When purchasing spawn, try not to choose times when the temperature is relatively high, and do not use spawn that has already aged.

5. Too much water in the compost

If there is too much water in the compost and then high-temperature weather is encountered when covering with soil, or if too much water is applied during high-temperature weather without timely ventilation, the mycelium will lack oxygen and shrink.

Control method: When stacking the material, water content must be controlled well; it should be neither too high nor too low. If, when turning the pile, the water content in the compost is found to be too high, it should immediately be spread flat and dried in the sun. Later, remember not to spray water too heavily and to pay attention to ventilation, so that the mycelium can resume growth.