Oyster Mushroom Pest and Disease Control Methods and Key Technical Points

In oyster mushroom cultivation, pests and diseases are major obstacles. Recognizing and promptly controlling them is of great significance to normal production.

If pests and diseases are discovered and measures are not taken in time, they can seriously affect oyster mushroom yields, sometimes causing total crop failure. Therefore, one should select fine and highly resistant strains, strengthen scientific management, and create environmental conditions favorable to mushroom growth but unfavorable to pest and disease reproduction, so as to prevent trouble before it occurs. Some common pest and disease control methods are introduced below:

1. Diseases

Diseases commonly fall into the following two categories:

(1) During the cultivation process, improper environmental conditions and management methods cause abnormal physiological activity. We call this physiological disease.

Rampant mycelial growth: the aerial mycelium on the surface of the mycelium is dense, affecting fruiting. The main cause of rampant mycelial growth is high air humidity and poor ventilation. The prevention method is to strengthen ventilation and reduce humidity.

Oyster mushroom big-foot: the cap of the fruiting body is extremely small, while the stipe is thick and long. This is mainly caused by lack of oxygen and poor ventilation. It can be prevented simply by strengthening ventilation and paying attention to light.

Oyster mushroom wilting: mushroom buds or fruiting bodies stop growing, gradually shrink, dry up and die, and rot. The main causes are insufficient moisture and excessive ventilation. The prevention method is to increase relative air humidity, keep the casing surface from drying out, and never let wind blow directly on the mushroom buds or fruiting bodies when ventilating.

Oyster mushroom pesticide damage: after the fruiting bodies are sprayed with pesticide (dichlorvos), the caps stop growing and a black edge forms and curls at the margin. The use of certain harmful pesticides should be prohibited.

Rust spots: rust-brown spots appear on the caps and stipes of oyster mushrooms. The main causes are poor ventilation and excessive humidity. The prevention method is to strengthen ventilation and reduce humidity.

(2) The fruiting body is contaminated by other weed molds, causing disease or death. We call this infectious disease.

A common disease of oyster mushrooms is dry bubble disease (brown spot disease), which mainly harms their normal growth. Its symptoms are white fuzzy mycelium on the surface of the fruiting body, brown spots appearing, and the cap shrinking and cracking.

Control method: lower the temperature and strengthen ventilation. Spray the affected area with 2% formaldehyde solution or 1:500 carbendazim.

2. Weed molds

There are many weed molds harmful to dried mushrooms, mainly the following:

(1) Penicillium and Trichoderma: Penicillium is white at first, then turns light green. Trichoderma is green from the start, and the green gradually deepens afterward. High humidity, poor ventilation, and an acidic environment make it prone to occur.

Control: the contaminated parts can be dug out, then sprinkled with carbendazim powder or quicklime. If contamination occurs within the substrate, it should all be burned or deeply buried.

(2) Neurospora: it occurs under conditions of 25°C-30°C; spores germinate in 6 hours, forming large amounts of cottony mycelium, and after 48 hours produce large amounts of pink conidia.

When preparing the compost, mixing in 1:500 carbendazim or meixiujing can prevent it from occurring. If it does occur, destroy or deeply bury it as early as possible.

(3) Gypsum-like mold: it often occurs on the surface of the compost, producing powdery, dense white mycelium.

Control method: increase the phosphorus fertilizer content of the substrate and spray with a 1:7 acetic acid solution.

(4) Aspergillus flavus: the mycelium is white at first, then produces large amounts of yellow spores. It occurs severely at high temperatures (above 27°C) and when the compost moisture is on the dry side.

Control method: lower the temperature and keep it below 25°C; when preparing the compost, keep the moisture appropriate.

3. Insect pests

(1) Mushroom maggots: they mainly harm the mycelium or fruiting bodies. The larvae of mushroom flies, mosquitoes, and the like are all white or yellow legless maggots that bore into and feed on the fruiting bodies. Control method: remove aged mycelium; take advantage of the phototaxis of adults by setting up insect-killing lamps to trap and kill them, or spray high-efficiency, low-toxicity pesticides, such as a 1000-fold dilution of trichlorfon, which can kill larvae and eggs.

(2) Mushroom mites: these are small insects belonging to the class Arachnida, order Acarina. They are very small and yellow-white; when gathered in piles they are pale yellowish-brown, like dust or rice bran. They have strong reproductive capacity and move quickly, feeding on mycelium and caps and causing mushroom buds to wilt.

Control: fully sun-dry the raw materials, spray dichlorvos in the surrounding environment, and after occurrence spray with a 800-fold dilution of 4% dicofol emulsion.

(3) Springtails: the adults have a flexible tail and jump like fleas, biting and eating the fruiting bodies. Control method: spray 0.1% derris extract.

There are also some pests such as slugs, ants, cockroaches, and mole crickets; for control, some quicklime can be scattered on the ground.

4. Treatment of old mushroom houses

Continuous cultivation of oyster mushrooms indoors or in tunnels often causes severe damage from pests, diseases, and weed molds, leading to failure. This results in high yield in the first cultivation, severe contamination in the second and third, and even no harvest. The reasons: because there is no disinfection after each cultivation, harmful metabolic products produced during oyster mushroom growth accumulate on the bed frames and tunnel walls. Mycelial aging, and the darkness, dampness, and poor ventilation of the room or structure, cause weed molds to breed and pests to run rampant.

Control method: pay attention to environmental sanitation; wash and scrub the walls with 5%-6% alkaline water; scatter quicklime on the ground, or spray carbolic acid to eliminate weed molds. In addition, spray insecticides to eliminate harmful insects. Use formaldehyde, sulfur, and other chemicals for sealed fumigation and disinfection.

5. Measures to prevent allergy to oyster mushroom spores

Oyster mushrooms should be harvested promptly after maturing. If harvested after the spores are released, it will, on the one hand, affect the formation of the next flush of mushrooms; on the other hand, it poses a serious hazard to the health of workers.

Oyster mushroom spores can cause allergic reactions in most people, producing symptoms such as coughing, thick phlegm, shortness of breath, and low fever.

Prevention methods: harvest promptly; after maturing, harvest promptly before the spores are released; before workers enter the mushroom house, first spray atomized water so that the spores settle to the ground with the water droplets, reducing the spore content in the air.

In addition, relevant materials state that when the caps are 2-3 cm, spray sodium glutamate nutrient solution as a top dressing. The formula is: 100 jin of water, 1 jin of sugar, 0.1 jin of sodium glutamate (monosodium glutamate also works), and 100 tablets of vitamin B1. Spray once a day. This can increase yield and delay the time of spore release.

If the human allergic reaction is severe, one should stay away from the original work for four months.