Strictly control the spawn production process when cultivating oyster mushrooms
Green mold, also known as Trichoderma viride, is one of the most serious pathogens harming oyster mushrooms. It causes damage at different production stages of oyster mushrooms. Once the disease occurs, it leads to reduced yields in mild cases and total crop failure in severe cases, becoming an important obstacle restricting the development of oyster mushroom production. Through several years of exploration and experimentation, the integrated control measures are summarized and introduced as follows...
Mother culture -> stock cultureWhen purchasing test-tube mother culture, pay attention to identifying its quality and carefully check the growth of mycelium in the test tube to avoid buying aged mother culture. Generally speaking, healthy mother culture shows white, thick mycelium with neat tips. If the mycelium is dry and scattered or the medium shrinks, and there is yellow liquid at the bottom of the bottle, it indicates that the mycelium has aged. Do not purchase it.
From mother culture to stock culture is the first expansion cultivation process of the spawn. Specific methods:
Material preparation: test-tube mother culture, beer bottles (prepare according to the amount of 1 test-tube mother culture inoculating 12 beer bottles); corn kernels or wheat kernels (prepare according to the amount of 1 beer bottle holding 250-300 grams of corn kernels or wheat kernels), etc.
Operation process: first treat the culture material. If wheat kernels are selected, soak them in water for 24 hours (change the water 3 times during this period to prevent acidification); if corn kernels are selected, because their seed coat is thicker and not easy to soak through, they need to be cooked before use. Note that when cooking corn kernels, control the heat properly. The corn kernels should neither "split open" nor be cooked on the outside while still raw inside.
When the amount of culture material loaded into the beer bottle reaches 4/5 of the bottle, seal the mouth with a cotton plug and wrap the outside with kraft paper to prevent the cotton plug from being soaked by steam during high-temperature sterilization. Then place the bottles on a steamer for high-temperature sterilization for about 12 hours.
After sterilization is completed, wait until the bottle temperature drops to 30°C, then transfer them to a sterile inoculation box for inoculation, that is, use an inoculation needle to pick up a small amount of mycelium from the mother culture test tube and quickly put it into the beer bottle, seal the mouth with a cotton plug, and wrap the outside with kraft paper. Then place the inoculated beer bottles indoors at about 25°C for preservation to promote mycelial growth. Generally, stock culture can be obtained after 20-25 days.
Reminder: Good stock culture mycelium is dense, white, uniformly growing, thick, cottony, and shows wall-climbing phenomenon. After the stock culture fills the bottle, it must immediately be expanded and propagated into cultivation spawn; otherwise, once the nutrients are exhausted, the mycelium will age and even die.
Stock culture -> first-grade cultivation spawn
The expansion and propagation of stock culture produces cultivation spawn. However, because the amount of stock culture is relatively small, if it is directly transferred into spawn bags for mushroom production, not only will the spawn-running period be prolonged due to the small amount of spawn and weak spawn vigor, but fruiting will also be uneven because the growth speeds at the two ends of the spawn bag are inconsistent. Therefore, it is recommended that mushroom growers adopt the spawn production model of small bags first and then large bags, that is, first inoculate the stock culture into small spawn bags for small-bag spawn production, and then transfer it into large spawn bags for formal cultivation. In this way, sufficient spawn-running speed and uniformity can be ensured, the spawn vigor is strong, and the probability of contamination by foreign bacteria is small.
Material preparation: first-grade cottonseed hulls (add water to moisten until water appears between the fingers when squeezed but does not drip; add an appropriate amount of lime to adjust the pH, stir evenly); small spawn bags (polyethylene plastic bags with specifications of 18 cm x 40 cm x 0.03 cm or 22 cm x 45 cm x 0.04 cm; prepare according to the amount of 1 beer bottle divided into 10 small spawn bags), etc.
Operation process: first put the previously prepared culture material cottonseed hulls into small spawn bags, tie both ends tightly, then place them on a steamer for high-temperature sterilization, maintaining the process for 20 hours when the temperature reaches 100°C. After sterilization is completed, place them in a ventilated and cool place to cool down. When the temperature is below 30°C, inoculation can be carried out. To facilitate inoculation, use an inoculation spoon to pour all the stock culture in the beer bottle into a small basin, or first wrap the beer bottle with adhesive tape several times, then break the bottle, remove the broken glass, and put the stock culture into a small basin for later use. During inoculation, use an inoculation spoon to put the stock culture into both ends of the small spawn bag. Finally, place the inoculated small spawn bags in a place with relatively constant temperature for cultivation. Generally, the mycelium can fill the whole bag in about 20 days.
Reminder: When placing the inoculated small spawn bags, note that because residual heat remains in the spawn bags and the mycelium also generates a large amount of heat during growth, they should not be stacked too high. Generally, stacking 3-4 layers in a "#" shape is sufficient to facilitate ventilation and heat dissipation and avoid "spawn burning." In addition, during the cultivation process of first-grade cultivation spawn, the bags should be turned frequently to prevent heat accumulation. At the same time, check the mycelial growth and whether there is contamination. Generally, turning the bags 3 times during the entire cultivation process is sufficient. After the mycelium is full, it must immediately be transferred to large spawn bags; otherwise, it is easy to cause mycelial aging and reduce its production efficiency.
First-grade cultivation spawn -> second-grade cultivation spawn
At present, oyster mushroom cultivation is mostly based on raw material cultivation. The culture material is mainly cottonseed hulls, with appropriate amounts of corncob, bran, lime or gypsum, sugar or cornmeal, trace elements, inorganic salts, etc. added to make the nutrition comprehensive and balanced. Because it is raw material cultivation, the culture material must be treated with chemical sterilization before use. Method: when adding water and mixing the culture material, mix in kemeiling (sodium dichloroisocyanurate), with 0.5 kg of kemeiling mixed into 500 kg of culture material, then cover it with plastic film and let it sit for about 12 hours. Finally, divide the culture material into large spawn bags. Note that in this step, it is advisable to use the method of "four layers of spawn and three layers of material" for bagging and sowing to speed up spawn running and improve fruiting results. According to this method, one small bag of cultivation spawn can be divided into 2-3 large spawn bags.