Key Technical Points and Management Measures for Cold and Freeze Protection of Edible Fungi

The main varieties of edible fungi cultivated in winter are low-temperature varieties such as the button mushroom (Agaricus bisporus), enoki mushroom (Flammulina velutipes) and shiitake (Lentinula edodes), which have relatively strong tolerance to low temperatures. The mycelium itself mostly stops growing at low temperatures and enters a dormant state. In addition, some mushroom species have casing soil on the bed surface, which also provides a certain insulation capacity. Therefore, low temperatures will not cause much harm to edible fungi. Even if a small portion of the mycelium on the surface suffers freeze damage, the mycelium inside can still remain viable.

The extreme minimum temperature for mycelium growth is between 3-6°C. If temperatures below 0°C occur, raising the temperature by just 2-3°C in the mushroom shed can reduce freeze damage to the mycelium. However, since most mushrooms are mainly cultivated in fields, doing a good job of insulating mushroom sheds, preventing mycelium cells from freezing, and avoiding mechanical damage are the top priorities in current cold and freeze protection work for edible fungi.

The main technical measures for preventing freeze damage:

1. Stop watering immediately and keep the substrate surface as dry as possible.

2. Strengthen insulation management of the mushroom shed. Small arched tunnels can be set up inside the greenhouse; covers such as plastic film and straw curtains can be added on the outside of the shed for insulation and dehumidification. Use plastic film as a skirt around the bottom inside the shed to reduce cold air invasion from the bottom; plug gaps to minimize heat loss through gaps; pile crop straw on the north side of the greenhouse to form a windbreak for wind protection and cold prevention; reduce the number of times entering and leaving the mushroom house. This can make the temperature inside the shed 3-5°C higher than the outside, which is basically enough to maintain mycelium viability.

3. Seize the opportunity of rising temperatures at noon to ventilate in a timely manner and prevent the cultivation substrate from deteriorating and turning sour.

4. Promptly clear accumulated ice and snow on the roof and around the mushroom shed to prevent the shed from collapsing.

5. Dig drainage ditches around the mushroom shed to keep drainage smooth and avoid rain and snowmelt from invading the mushroom substrate.

6. Where conditions permit, referring to the mushroom secondary fermentation method, steam can be introduced into the mushroom shed to raise the temperature inside. However, the temperature is difficult to control, the difficulty is relatively high, and if heating continues for many days, the cost is relatively high.

7. After temperatures steadily rise again, promptly spray water on the substrate surface and resume routine management.