Common pests and diseases of Pleurotus eryngii cultivation, their causes, and prevention and control strategies

Diseases can occur during the mycelium, button, and fruitbody stages of Pleurotus eryngii, which are classified into four major categories: **contaminating fungal diseases (competitive fungi), physiological diseases, bacterial diseases, and insect pests**. The high-incidence types in greenhouse/factory cultivation are summarized as follows:

1. Competitive miscellaneous bacteria (main threat during the fermentation period)

1. **Trichoderma viride (Green mold)**

 - Symptoms: Green patches appear on the material surface, mycelium is suppressed and decomposed, and the fungus bag rots.

 - Causes: Inadequate sterilization, poor disinfection during inoculation, sterilization due to excessively high material temperature, and excessive environmental humidity.

2. **Mucor, Rhizopus (Mucor longus)**

 - Symptoms: white fluffy long hair, rapid spread, competition for nutrients, and souring of feed bags.

 - Causes: High moisture content in the culture medium, insufficient sterilization duration, and unclean cooling environment.

3. **Aspergillus (Aspergillus niger, Aspergillus flavus)**

 - Symptoms: Yellow and black powder-like colonies.

 - Causes: mold growth in raw materials, high temperature and humidity in the cultivation environment.

4. **Alternaria (red bread mold)**

 - Symptoms: Orange-red powdery spores, highly contagious, capable of causing widespread contamination once outbreaks occur.

 - Causes: Broken bags, bacteria-carrying operations, and easy diffusion in high-temperature environments.

The core of miscellaneous bacteria prevention and control lies in strictly controlling raw materials, standardizing sterilization, conducting aseptic inoculation, and maintaining reasonable temperature and humidity control. Contaminated mushroom bags should be promptly removed from the mushroom shed and not piled up on site.

II. Bacterial diseases (highly prevalent during the fruiting period, harming the fruiting body)

1. **Bacterial brown spot disease (spot disease)**

 - Symptoms: Yellowish-brown pitted spots appear on the cap and stalk of the mushroom, which do not penetrate deep into the interior. The spots expand when the humidity is high.

 - Causes: Directly spraying water on the mushroom body, poor ventilation, high humidity inside the shed, and bacteria in the water source.

2. **Mushroom rot disease (bacterial soft rot)**

 - Symptoms: The mushroom body becomes soft and rots with a water-soaked appearance, accompanied by a fishy odor.

 - Causes: high temperature (>18℃), persistent high humidity, excessive carbon dioxide, and failure to promptly clean up residual mushrooms.

III. Physiological diseases (caused by improper management rather than pathogens, commonly seen in production)

It is not a disease or pest, but it seriously affects commercial mushrooms, and many growers are prone to confuse it

1. **Deformed mushroom (long-stalked small cap)**

Reason: Poor ventilation, high CO₂ concentration.

2. **Shrinkage and death of mushroom buds (stiff buds)**

Reasons: Large temperature fluctuations, inconsistent humidity levels, direct spraying of cold water on the mushroom buds, and insufficient nutrients.

3. **Cracked Mushroom**

Reason: Sudden drop in humidity and direct exposure to dry and strong winds.

4. **Knot mushroom, wart-like protrusion**

Reason: Improper scratching and drastic temperature fluctuations.

5. **No mushrooms growing, buds not appearing for a long time**

Reasons: Insufficient post-ripening of mycelium, persistently high temperature, and lack of diffused light.

IV. Common Pests

1. Mushroom fly (eye-worm)

- The larvae are white and thin, feeding on mycelium and mushroom roots, causing the mushroom buds to wither and die; the adults are small black flying insects.

- Transmission: Carrying various bacteria, exacerbating the spread of diseases.

2. Mushroom fly

- The larvae are worm-like and harm the mycelium and young mushrooms in the material layer.

3. Springtail (Cigarette ash bug)

- Small in size, with strong jumping ability, they gather at the base of the mushroom stem to feed, preferring humid environments.

4. Mites (bacteria mites)

- Small white spots visible to the naked eye, which consume mycelium, causing mycelium to regress and fail to produce mushrooms; often originating from moldy raw materials.

5. Snails and slugs

- Feeding on the mature mushroom caps of Pleurotus eryngii, leaving bite marks, which is more common in open-air greenhouses and on wet ground.

V. Principle of Integrated Prevention and Control (Prioritize Physical Prevention and Control for Edible Fungi, Use Pesticides with Caution)

1. **Prioritize prevention**

Fully dry the raw materials and remove any moldy ones; clean and disinfect the mushroom sheds periodically; keep waste materials away from the cultivation area.

2. **Environmental control**

Prevent high temperatures during the spawn-inducing period; during the fruiting period, avoid directly spraying the mushroom buds, ensure regular ventilation, and avoid prolonged exposure to humidity levels above 95%.

3. **Physical prevention and control**

Install insect-proof nets and yellow sticky traps to lure and kill mushroom flies and mosquitoes; promptly remove waste mushroom bags and defective mushrooms to cut off the source of insects.

4. **Medication reminder**

Pleurotus eryngii is a type of edible fresh mushroom, and the use of highly toxic pesticides during the fruiting stage is strictly prohibited. If pesticides are indeed necessary, only registered specialized pesticides for edible mushrooms may be used, and strict adherence to the safety interval period is required. No pesticides are allowed before harvesting.