How to prevent and control non-physiological diseases of mushrooms?

(1) Deformity Deformed mushrooms are mostly induced by temperature differences or unfavorable environments; they may also be related to the strain used. Deformities mainly include the following types:

1. Hollow stipe. Mushrooms on the bed look normal, but when the base is cut off, part of the stipe is found to be hollow, usually with a ring-shaped cavity around a hard core. Afterwards, the cut surface of the stipe may crack and then curl backward, causing the mushrooms to lose their appealing appearance and decline in quality. This is mainly caused by low air humidity during the fruiting period, rapid evaporation of water from the mushroom bodies, excessively dry casing soil, and the fruiting bodies being unable to obtain water.

2. Split stipe. The stipe splits vertically, sometimes accompanied by horizontal splitting, causing the stipe segments to curl upward and downward. This is a splitting symptom induced by the mushrooms first growing in very moist casing soil, then the casing soil drying, and then the casing soil humidity being rapidly increased again.

3. Swollen stipe. Occasionally, mushroom stipes can be seen swollen, possibly at the base, middle, or top of the stipe.

4. Hard gill disease. Diseased mushrooms with opened caps. Viewed from below upward, they are pale in color, and the gills are very shallow or absent. If the cap ruptures, the cap usually appears thicker than normal.

5. Ugly-shaped mushrooms. Fruit body differentiation appears blurred and unclear, often associated with the first flush in autumn. They cannot develop normally and become various ugly-shaped mushrooms, ranging from nodular forms to fruit bodies whose shape is still somewhat distinguishable but whose caps are strangely shaped. Individual fruit bodies may also be joined together.

(2) Water-soaked disease The symptoms of affected mushrooms are clearly visible water-soaked areas, especially on the stipe. If the mushrooms are squeezed, water is released; moreover, sometimes mature fruit bodies spontaneously exude large amounts of clear or colored liquid and then rot.

(3) Mushroom bud diseases

1. Clustered mushroom buds. Large numbers of pinhead-sized small mushrooms are produced, and basically none of them can develop and grow. This occurs when the environment is too favorable for mushroom bud formation.

2. Clumped mushrooms. This disease should be distinguished from uneven fruiting. Uneven fruiting is obvious and has different causes. Clumped mushrooms refer to mushrooms occurring in piles, which is related to periodic low temperatures during mushroom bud formation.

3. Mycelial mat. After the mycelium grows through the casing soil, a thick layer of white mycelium forms on the casing surface. The mycelial mat is impermeable to water, and fruiting is impeded. This is caused by high concentrations of carbon dioxide combined with high humidity and high temperature. In addition to adjusting environmental conditions, the remedy is to lightly scratch the surface immediately when the mycelial mat just begins to form and then add a new layer of casing soil.

4. Mushroom bud death. This generally appears in a somewhat later flush; the casing soil is well colonized, yet the mushroom buds still die and no mushrooms are produced in the patch. It is usually caused by the presence of a water-impermeable mycelial layer in the casing soil, leading to water accumulation on the casing surface. This disease is the opposite of mycelial mat disease; its usual cause is insufficient watering in the early stage of mushroom cultivation, allowing dense mycelium to colonize the dry casing soil.

(4) Dirty mushrooms When mushrooms fruit in casing soil that is too deep, they are often covered with casing soil. The cause is delayed fruiting or drying of the casing surface layer, which leads to deep fruiting.

(5) Rose comb disease Pink, porous gill tissue forms on the cap surface. It appears as small warty or honeycomb-like structures, distributed from the gills onto the cap. The diseased mushrooms are pink or rose-colored. It is caused by contamination with hydrocarbons, phenols, and other compounds, as well as excessive use of certain insecticides and contaminated casing soil.

(6) Browning Caused by bacterial blotch disease, generally due to high humidity combined with frequent use of overly strong sodium pentachlorophenate solution to disinfect mushroom beds.

(7) Scaling Caused by a natural response to dry air or by sodium pentachlorophenate fumes from the mushroom bed.

(8) Latent dry rot disease The symptoms are similar to dry rot disease, but growth can recover and normal fruit bodies can be produced. It is caused by long-term excessive watering.