Six Major Mushroom Disease Prevention and Treatment Methods for Winter

Brown rot disease

When mushrooms are infected at a young stage, they cannot differentiate, and later form irregular grayish-white "lumpy heads," such as extremely thick caps resembling fists, or caps and stipes that are difficult to distinguish, with a layer of "white fuzz" growing on the surface. When the temperature is above 20°C, within 4-5 days the diseased mushrooms darken in color, then rot, exuding a brown, soy-sauce-like liquid, and rot and emit a foul odor; if the shed temperature is below 20°C, this process takes longer, requiring about 7 days or more. When fruiting bodies are infected at the mid-growth stage, brown lesions appear on the cap surface, the stipe becomes thick and swollen, and then the mushroom body softens, also exuding dark brown droplets. When the diseased mushroom is cut open, its internal tissue changes from the original white to a blackish-white, and after the mushroom body soft-rots it turns blackish-brown and emits a foul odor. It is mainly spread through pathogen spores via air, human activity, tools and other channels.

Prevention and treatment measures: Clean up the environmental sanitation. Before reusing old mushroom sheds that were infected last year, scrape off a layer of wall surface, then pile up straw and set it on fire, then re-cover the shed and spray a solution of carbendazim. The dosage is 1 kg of 50% pure carbendazim powder per 100 sq m of mushroom shed, mixed with about 80 kg of water, sprayed evenly; after sealing the shed for 2 days it can be put into use. When the temperature is below 13°C, the pathogen damage can be inhibited. Scrape off 0.2-0.3 cm of the casing surface and spray a 70-100 times dilution of Baibing Quwuzong solution in a carpet-like manner, which can effectively inhibit or kill some pathogenic bacteria. Preventive measures can also be taken: after the mushroom bags are brought into the shed or after sowing, spray a 100-150 times dilution of Baibing Quwuzong solution, strengthen once more before fruiting, and at the early stage of disease, spray continuously 2 times for very good results.

Brown spot disease

When disease occurs early, it can cause deformation of mushroom primordia; when young mushrooms are infected, brown stripes appear on the stipe or base, brown spots are distributed on the cap, and diseased mushrooms grow to one side. When cut open and observed, the internal tissue is yellow-brown, dry and loose, and the mushroom body does not rot and has no foul odor. At the initial onset, it may be caused by germination of pathogenic spores remaining in the soil and floating in the air, while the rapid spread after onset is through human bodies, tools, insects and even splashing water during watering.

Prevention and treatment measures: For shed treatment, refer to brown rot disease. For button mushroom production, the two-phase fermentation technique is recommended; casing soil materials should undergo routine sterilization treatment; after mushroom bags are brought into the shed or after casing soil is applied for shaggy ink cap mushrooms and button mushrooms, spray a 150 times dilution of Baibing Quwuzong in a carpet-like manner; at the early stage of disease, spray a 100 times dilution of Baibing Quwuzong continuously 2 times or more; when the damage is relatively severe, remove all diseased mushrooms, stop watering, ventilate and dry, burn the diseased mushrooms, clean the casing surface and brush with a 50 times dilution of Baibing Quwuzong; wash and brush all tools and materials that may carry pathogens with a 600 times dilution of carbendazim solution.

Soft rot disease

Also known as downy mildew, etc. After onset, the mushroom bed is covered by grayish-white mycelium of the pathogen, then turns dark gray-green or dark brown. The edible mushroom mycelium loses vitality due to lack of oxygen and infection by pathogen secretions, and it is very difficult to produce mushrooms afterward. Fruiting bodies that appeared before the severe damage first develop disease from the base, extending upward to the cap. At the initial stage, pale brown water-soaked lesions of varying sizes appear on the cap, which are then covered by the pathogen and die, finally rotting so that they collapse at a touch. Its pathogen spreads through casing soil materials, water, insects, human bodies and air movement.

Prevention and treatment measures: For shed treatment, refer to the above. Strengthen the improvement of ventilation conditions in the mushroom shed to reduce as much as possible the surface humidity of the mushroom beds or walls, especially after artificial watering, timely ventilation is even more needed; adjust the pH of the substrate to about 7, and for alkali-tolerant varieties it can be adjusted to about 9; at the early stage of disease, when pathogen mycelium is visible on the mushroom bed surface, spray a 100 times dilution of Baibing Quwuzong; when the disease is relatively severe, scatter a small amount of lime powder over the affected area as a cover; when damage occurs over a large area, remove the diseased mushrooms and clean the casing surface and casing soil materials, spray a 100 times dilution of Baibing Quwuzong, replace with new treated casing soil materials, and then spray a 150 times dilution of Baibing Quwuzong solution to prevent the occurrence of the disease.

Rust spot disease

The damage symptom is the formation of round or oval rust-colored lesions on the cap surface. The lesion edges are neat, with a depression in the middle. After the spots dry and shrink, the cap cracks, forming asymmetrical fruiting bodies. The stipe is less infected, and the gills are basically not infected. This disease is a bacterial disease. Its pathogen lurks in various raw and auxiliary materials, casing soil materials and water. When the temperature is above 15°C and air humidity is greater than 85%, the pathogen is extremely active, spreading through human bodies, air movement, insects sneaking in, tools carrying it and other channels, and it is more likely to be induced especially when humidity is high and ventilation is poor.

Prevention and treatment measures: Before the mushroom shed is put into use, it should be thoroughly disinfected; when using fermented material for cultivation, the substrate should be uniformly decomposed; during the mycelium growth and fruiting periods, persist in spraying Baibing Quwuzong to achieve prevention; at the initial stage of disease, spraying a 150 times dilution of Mogu Shabingling solution is sufficient; when the disease is relatively severe, remove the diseased mushrooms, clean the casing surface, and spray a prepared 70 times dilution of Mogu Shabingling solution continuously 2 times or more; during daily management, air humidity should be maintained at about 85%, not too high, and reasonable ventilation should be maintained, especially after watering, the surface moisture on the caps should be evaporated within 1 hour, otherwise staying too long easily induces the disease.

Yellow spot disease

At the initial stage of infection, small spot-like pale yellow patches appear on the cap, which expand in scope and infect other fruiting bodies as the fruiting bodies grow, then the color deepens and spreads to the entire cap. At the late stage of infection, the mushroom body secretes yellow-brown water droplets, the diseased plants stop growing, then shrink and die.

This pathogen prefers high temperature and high humidity environments, and is extremely likely to induce this disease especially when the temperature is stable above 20°C, humidity is above 95% and carbon dioxide concentration is relatively high; when the water used in the substrate and mushroom shed is unclean, the incidence of this disease is also very high.

Prevention and treatment measures: Strengthen ventilation to reduce the carbon dioxide concentration in the shed to below 0.5%; reduce shed humidity, especially in seasons or time periods when heat preservation is needed, control air humidity at about 85%; at the early stage of disease, spray a 70 times dilution of Mogu Shabingling or Huanggu Yipenling solution 2 times to effectively inhibit it; after the mid-stage of disease, remove the diseased mushrooms, and after cleaning the casing surface and doing sanitation, spray a prepared 50-70 times dilution of Mogu Shabingling solution continuously 2-4 times. However, note that after spraying, seal the shed for 1-2 hours, then strengthen ventilation and lower the shed temperature.

Discoloration disease

Young mushroom caps change from gray-brown or black-brown to partially or entirely yellow, scorched yellow or tile blue, inhibiting fruiting body growth and noticeably slowing the growth rate, growing into deformed mushrooms or caps that shrink and curl upward, seriously affecting commercial quality.

Prevention and treatment measures: The cause of this disease is that when coal stoves are used for heating in low-temperature seasons, the concentrations of carbon monoxide and carbon dioxide in the shed are relatively high, and after fruiting bodies inhale such gases they develop short-term poisoning symptoms, but the caps (especially the edges) discolor; some chemical substances in poor-quality plastic shed films, after being precipitated by condensed water and dripping onto fruiting bodies, can also cause this type of disease, often mostly turning the caps scorched yellow; certain pesticide residue components in casing soil materials, pesticide residues in sprayers, the intrusion of certain harmful gases from outside, etc., can also lead to this problem. Mushroom growers should identify the cause based on the specific production situation and "prescribe the right remedy" to solve it, and must not blindly apply pesticides.