What are the precautions for autumn mushroom cultivation?

The growth and development of mushrooms is very sensitive to temperature, and higher temperatures are unfavorable for mushroom growth and development; therefore, the suitable period for cultivating mushrooms is generally winter and spring. In order to meet market demand, in recent years some places have been trying autumn mushroom cultivation. For this reason, this article introduces several prominent issues that should be noted in autumn mushroom cultivation as follows:

1 Cultivation season and altitude. According to the biological characteristics of mushrooms, the temperature range for mycelial growth is 6-32°C, and the temperature range for fruiting body growth and development is 7-25°C. Therefore, most mushroom cultivation areas are distributed in temperate and subtropical zones, yet the world's largest mushroom farm was built in tropical Indonesia. Indonesia's Java Diengdjaga Company, with the cooperation of Dutch technology, took advantage of the lower temperatures in high-altitude mountainous areas and, in the 1990s, built a fresh mushroom farm with an annual output of 30000 t on a high mountain at an altitude of 2000 m northwest of Yokjakarta city in Central Java, carrying out year-round mushroom cultivation. This is a very good reference for developing autumn mushroom cultivation in our country. In China's high-altitude mountainous areas, when the average temperature reaches an appropriate range in a certain season, it is suitable for cultivating mushrooms. However, for autumn cultivation of mushrooms in most areas of Fujian, the altitude requirement is at least above 900-1200 m for late autumn cultivation, and the earlier the cultivation time, the greater the required altitude; the lower the latitude, the higher the required altitude. Otherwise, more mushroom buds will die in the early stage.

2 Selection and breeding of strains. A prominent problem faced by autumn mushroom cultivation is high temperature. In recent years, the selection and breeding of excellent mushroom strains in China has progressed rapidly, but so far there are still very few strains that can tolerate high temperatures. Some strains can tolerate a certain degree of high temperature, but their yield and quality are not ideal. This is also an important factor making large-scale production of mushrooms in summer and autumn cultivation difficult at present. Therefore, autumn mushroom cultivation requires both selecting high-altitude areas and breeding strains with relatively strong high-temperature tolerance. At present, the mushroom strains generally suitable for autumn cultivation in high-altitude areas are only As2796 and some appressed-type strain No. 176 and high-temperature mushrooms. High-temperature mushrooms can obviously tolerate a high temperature of 38°C, but their yield is not high.

3 Design of mushroom sheds. The size of the mushroom shed affects the absorption of thermal radiation energy and gas exchange, thereby affecting the ecological microclimate inside the shed. Therefore, different seasonal mushroom cultivation has different requirements for mushroom shed setup. Generally, winter and spring mushroom sheds should be small, while summer and autumn mushroom sheds should be large. For winter and spring mushroom cultivation in eastern Fujian, mushroom sheds are mostly 200-250 sq m; for late autumn cultivation in the Shanghai suburbs, mushroom sheds are mostly 900-1100 sq m, but ventilation and air exchange in such large mushroom sheds in winter are not ideal, and carbon dioxide and other substances accumulate seriously. Indonesia's Green Giant Company designed mushroom sheds of 250 sq m each in 1980, and designed mushroom sheds of 600 sq m each in 1988. Therefore, the author believes that the mushroom shed design for autumn mushroom cultivation should preferably be 650-850 sq m.

4 Mushroom death phenomenon. In autumn mushroom cultivation, due to the influence of high temperature and other factors during fruiting, some small mushroom buds often shrink, turn yellow, and finally die. In severe cases, small mushroom buds on the bed surface die in batches. However, it must be noted that the cause of this phenomenon is not simply high temperature; many unfavorable factors can cause mushroom bud death. Common causes of mushroom death include the following. ① Continuous high temperature causing mushroom death: when the mushroom house continues at a high temperature above 25°C, nutrients in the small mushroom buds flow back to the mycelium, leading to a lack of nutrients and water; ② Improper water management causing mushroom death: mainly spraying closed-door water during high temperature and spraying too much or too little water; ③ Overdense fruiting and overly high fruiting positions causing mushroom death: mainly caused by too thin casing soil and untimely spraying of fruiting water; ④ Improper pH causing mushroom death: too low or too high pH of the casing soil and applied water affects enzyme activity in mycelial cells, cell membrane permeability, and their ability to absorb metal ions; ⑤ Poor ventilation causing mushroom death: poor ventilation, insufficient oxygen, and accumulation of harmful gases affect normal metabolic activities. In view of the above reasons, to prevent mushroom death in autumn cultivation, while avoiding the effects of continuous high temperature, it is also necessary to prevent the pH of casing materials and water from being too high or too low, pay attention to ventilation and air exchange and scientific water management, and follow the water management principles of "water for knotting mushrooms should be generous, water for fruiting should be steady, water for turning flushes should be heavy, and maintenance water should be frequent," and "spray more on sunny days, spray less on cloudy days, spray frequently when there are many mushrooms, and spray cautiously when there are few mushrooms," avoiding spraying closed-door water.

5 Pest and disease control. In autumn mushroom cultivation, pests and diseases are rampant, with many types occurring, among which the most important include the competitive contaminant gypsum mold; infectious diseases such as Mycogone perniciosa disease, brown spot disease, and soft rot. Comprehensive control measures of "prevention first, with medication as a supplement" should be adopted.

5.1 Disinfection of the mushroom house. The mushroom house should be built in a place with no pollution sources, the surrounding area should be kept clean and sanitary, and the mushroom house should be disinfected properly. The compost should undergo secondary fermentation.

5.2 Proper soil disinfection. Two methods can be used: sun exposure treatment and chemical treatment. For sun exposure treatment, the soil retrieved for later use is placed on a grain-drying yard or other clean site and exposed to the sun for 3-5 days. For chemical treatment, chemicals are used to disinfect the casing soil. Generally, for 110 sq m of casing soil, about 100 kg of a 1000-fold solution of agents such as Youbaojing or Shibaogong is sprayed, covered with film and piled for more than 24 hours, then opened to release gas before being used for casing on the bed.

5.3 Scientific management. Water used in the mushroom house should be hygienic; polluted field water or ditch water must not be used. Ventilation and air exchange should be strengthened, and appropriate temperature and humidity should be maintained to avoid high temperature and high humidity inducing pests and diseases. Waste, mushroom stubs and roots, and diseased fruiting bodies should be removed in time to prevent the invasion and spread of pest and disease sources.

5.4 Chemical control. ① White gypsum mold: spread lime powder over the contaminated compost surface to kill the colonies of this fungus and neutralize the acid produced by the pathogen's reproduction. ② Mycogone perniciosa: use 0.1% Youbaojing etc. and spray 50 kg of solution per 110 sq m on the mushroom bed. ③ Brown spot disease: use one of 0.1% carbendazim, Shibaogong, etc. and spray around the diseased fruiting bodies to control the center of infection; or use 200-400 ml/kg streptomycin or oxytetracycline sprayed every other day for control. ④ Soft rot: use 0.1% carbendazim or Youbaojing for control. ⑤ Mushroom flies and mushroom mosquitoes: use a 1500-fold solution of 5% Ruijingte to spray the mushroom bed and surrounding environment, and it can also be used together with heavy watering to achieve the purpose of killing insects.