Why Do Oyster Mushroom Yields Drop Over Time?
1. Serious Pollution of The Cultivation Environment
The vast majority of growers cultivate in greenhouses for years. The deterioration of environmental conditions and incomplete disinfection are the main reasons for the reduction in the yield of oyster mushrooms. According to the test, the base number of miscellaneous bacteria in the new site is 63.95 per square meter, 95% of bacteria, and 150 colonies per square meter. After the first cultivation, the base number of miscellaneous bacteria will be 20 times higher than before. These miscellaneous bacteria control the growth of oyster mushrooms to a certain extent. The more times of cultivation, the lower the yield of oyster mushrooms. In addition, the metabolic substances of oyster mushrooms themselves also have a certain control over their growth. Therefore, it is best to change the cultivation site every 2 to 3 years or stagger the cultivation season in a planned way. It is also possible to grow mushrooms locally and produce mushrooms in other places.
2. Raw Material Issues
At present, the main raw material for cultivating oyster mushrooms is cottonseed hulls. The latest data shows that due to the continuous advancement of science and technology, the continuous updating of cotton oil plant equipment, the utilization rate of products is getting higher and higher, and the nutritional content of cottonseed husks is getting less and less. Moreover, cottonseed husks are divided into many grades, such as large shell short lint, medium shell medium lint, small shell long lint, etc. Except for professional big farmers, most cultivators do not know the secret and think that as long as it is cottonseed husk, it will be fine. Cottonseed husks with large shells and short lint have low water content and low nutritional content. The second-wave mushrooms are difficult to grow due to lack of water in the material; while cottonseed husks with small shells and long lint have high water content and rich nutrition, and the yield of oyster mushrooms is higher. The yield difference between the two is about 20%.
3. Strain Quality Issues
In the production of oyster mushrooms, the quality of strains is the key to directly affecting yields and benefits. The quality of strains is difficult to identify intuitively. Two tubes or two bottles of strains full of culture medium have no difference in appearance, but their technical content and experimental input are completely different. Except for professional big farmers, most cultivators buy third-level strains. Edible mushroom mycelium has the characteristics of unlimited growth. The more times the cells divide, the higher the degree of aging and the more mutations there will be; the more times the expansion and transfer, the greater the production volume, the higher the degree of aging and the more mutations there will be. Some people, for the sake of profit, buy back the mother strain from scientific research institutions, expand and transfer arbitrarily, and use it all year round. This is also one of the reasons for the decline in the yield of oyster mushrooms.