What are the reasons why oyster mushroom yields are getting lower and lower

Recently, many growers have called to ask: why are oyster mushroom yields getting lower and lower these days? They are much worse than in previous years. To this end, the author conducted a survey and found the following problems:

Serious pollution of the cultivation environment. The vast majority of growers cultivate in greenhouses year after year. Deteriorating environmental conditions and incomplete disinfection are the main reasons for reduced oyster mushroom yields. According to tests, the background count of contaminating microorganisms in a new site was 63.95 per square meter, with bacteria accounting for 95%, and 150 colonies per square meter. After the first cultivation cycle ended, the background count of contaminating microorganisms was 20 times higher than before. These contaminating microorganisms control the growth of oyster mushrooms to some extent, and the more cultivation cycles there are, the lower the oyster mushroom yield. In addition, the metabolic substances of oyster mushrooms themselves also exert a certain level of control over their growth. Therefore, the cultivation site should preferably be changed every 2 to 3 years, or the cultivation seasons should be staggered in a planned way. It is also possible to imitate the southern model: spawn running locally and fruiting in a different location.

Raw material problems. At present, the main raw material for cultivating oyster mushrooms is cottonseed hulls. The latest information shows that due to continuous technological progress and the continuous upgrading of equipment in cotton oil mills, the utilization rate of products is getting higher and higher, and the nutrient content of cottonseed hulls is getting lower and lower. Moreover, cottonseed hulls are also divided into many grades, such as large hulls with short lint, medium hulls with medium lint, and small hulls with long lint. Except for professional large-scale growers, the vast majority of growers do not know this secret and think that any cottonseed hulls will do. Large-hull, short-lint cottonseed hulls have low water content and low nutrient content, and the second flush of mushrooms is difficult to produce because of water shortage in the substrate; while small-hull, long-lint cottonseed hulls have high water content and rich nutrients, and oyster mushroom yields are relatively high. The yield difference between the two is about 20%.

Spawn quality problems. In agricultural production, everyone knows the principle that good seed produces good seedlings. In oyster mushroom production, the quality of the spawn is the key factor directly affecting yield and profitability. Spawn quality is very difficult to identify visually. Two bags or two bottles of spawn fully covered with culture medium may look completely identical in appearance, but their technical content and experimental investment are entirely different. Except for professional large-scale growers, the vast majority of growers buy third-generation spawn, and most of the individuals and units producing third-generation spawn are scattered in rural areas. The sources of spawn and production conditions are rather chaotic, blind expansion and transfer are common, and adulteration and counterfeiting are widespread. Edible fungus mycelium has the characteristic of unlimited growth. The more times cells divide, the higher the degree of aging, and the more mutations there will be; the more times of expansion and transfer, the larger the production volume, the higher the degree of aging, and the more mutations there will be. Some people, for the sake of profit, buy mother cultures from research institutions and expand and transfer them at will, using them year-round. This is also one of the reasons for the decline in oyster mushroom yields.