Detailed Explanation of Key Points of Mushroom Spawn Cultivation Techniques

Mushrooms are a very popular type of fungus on the market, and spawn is the key to mushroom yield. Superior spawn can be applied to a variety of cultivation scenarios. Below, taking the oyster mushroom (Pleurotus ostreatus) as an example, let us look at mushroom spawn cultivation techniques.

1. Nutrition: During the growth and development process, the main nutrient required is a carbon source, such as lignin, cellulose, hemicellulose, starch, sugars, etc. These substances mainly come from materials such as cottonseed hulls, sawdust, rice straw, corncobs and other crop straw.

2. Temperature: The temperatures required for vegetative growth and reproductive growth of mushrooms are different. The temperature range for mycelial growth is 5-23 degrees, with the most suitable temperature being 24-28 degrees. The most suitable temperature for fruiting body formation is 13-20 degrees; below 10 degrees growth is slow, and above 25 degrees fruiting is difficult. Within the fruiting temperature range, the higher the temperature, the faster the mushrooms grow, but the caps are thin, the quality is poor, and the color is light; at lower temperatures, the mushrooms grow slowly, but the caps are thick, the quality is good, and the color is dark.

3. Humidity: The water content of mushrooms reaches over 90%, with water being the main component. Water is the necessary metabolic environment for mushrooms to decompose and absorb various nutrients from the substrate of the culture material. Only substances that can dissolve in water can enter the mycelial cells and be absorbed and utilized. During the mycelial growth and development stage, the water content in the culture material is 60-65%, and the relative humidity of the cultivation site is below 70%. During the fruiting body growth period, the water content in the culture material is 65-70%, and the relative air humidity is 85-95%; below 80% the fruiting bodies grow slowly, and the cap edges dry and crack and curl upward. If it is above 95%, the caps are prone to discoloration and rotting. If the water content in the medium is below 55%, mycelial growth is slow or stops, and fruiting bodies cannot form; if the water content in the medium is above 70%, the mycelium often stops growing due to insufficient oxygen, causing the culture material to sour and become contaminated.

4. Air: The growth and development of mushrooms requires fresh air. Mycelium has a strong tolerance for carbon dioxide; when the carbon dioxide concentration in the medium reaches 10-15%, it can still grow vigorously, but when it exceeds 20%, the mycelium is inhibited. However, the formation and growth period of fruiting bodies is very sensitive to carbon dioxide concentration. When the carbon dioxide concentration in the mushroom shed reaches 0.3%, the stipes elongate and the caps develop poorly; when the carbon dioxide concentration reaches 1%, it is very difficult to form mushroom primordia.

5. Light: During the mycelial growth stage, oyster mushrooms do not need light, and under completely dark and constant temperature conditions, the mycelium grows best and fastest. This is mainly because the blue-violet light in the light spectrum has an inhibitory effect on oyster mushroom mycelium. During the fruiting stage, the environment needs a certain amount of scattered light, to the extent that a newspaper can be read normally in the fruiting site. The role of light is to induce fruiting and promote cap development. Research shows that: completely dark conditions cannot form mushroom primordia; insufficient light easily produces deformed mushrooms with long stipes and small caps; only under suitable light can mushroom primordia form and grow normally. However, strong light will hinder the normal growth of oyster mushrooms. When cultivating oyster mushrooms in caves or basements, the stipes sometimes fork a second time and the caps cannot spread normally, which is also caused by insufficient light. The color of the caps is also closely related to light: when light is strong the caps are dark, and when light is weak the caps are light; however, in winter cultivation, strong light exposure can be used.

6. pH: Mushrooms adapt to a relatively wide range of PH values in the medium, and can grow between PH4-PH9, but PH5.5-7 is suitable. During the steaming or fermentation process of the cultivation material and during mycelial growth, organic acids are produced, which lower the PH value of the medium. Therefore, when mixing the ingredients, magnesium sulfate, calcium carbonate, etc. are added as buffering agents to reduce the rate of PH change and achieve the effect of stabilizing the acidity and alkalinity.

Mushrooms are relatively delicate, and a single careless mistake may affect mushroom growth, and may even cause spawn contamination and result in a total loss of harvest. If the technique does not meet the standard, it is not recommended to cultivate mushroom spawn.