Cultivation of King Oyster Mushroom: How to Grow King Oyster Mushrooms? What Does King Oyster Mushroom Look Like
King oyster mushroom, also known as Pleurotus eryngii, is a rare new edible mushroom variety successfully developed and cultivated in recent years that combines food, medicinal and dietary therapy uses. The king oyster mushroom is a low-temperature strain, requiring about 50-60 days from spawning to fruiting. In the Yangtze River basin, cultivation bags can be prepared from October to November, with fruiting from November to January of the following year. Other regions can adjust the timing earlier or later accordingly. Let us take a look at the cultivation techniques for king oyster mushrooms!
Cultivation Raw Materials
There are many substrate materials suitable for king oyster mushroom growth, such as mixed wood chips, cottonseed hulls, waste cotton, sugarcane bagasse, wheat straw, bean straw, etc., all of which can serve as the main ingredient. To prevent puncturing the cultivation bags and to facilitate mixing and bagging (bottling), wood chips must be sifted, and straw materials must be crushed.
Supplementary materials may include wheat bran, rice bran, cornmeal, cottonseed cake powder, calcium carbonate, white sugar, gypsum powder, etc.
Cultivation Methods
King oyster mushroom cultivation can be done in bottles, boxes, or bags depending on the container used. Among these, bag cultivation is the most convenient and practical.
The bag cultivation procedure is: spawn production (including mother culture, stock culture, and cultivation spawn) → preparation of cultivation bags (including material preparation, mixing, bagging and sterilization) → fruiting management → harvesting and processing.
Cultivation Season
For cultivation under natural conditions, based on the suitable growth temperature for king oyster mushrooms, autumn-winter and winter-spring cultivation are generally preferred. However, in regions with higher winter temperatures, it is better to schedule fruiting from December to February, because temperatures that are too high or too low make it difficult to form primordia and are unfavorable for fruiting body growth and development. King oyster mushroom differs from other oyster mushrooms: if the first flush does not form normally, it will affect the occurrence of the second flush, which will inevitably affect total yield.
Therefore, whether in the south or north, the cultivation period should be properly scheduled according to the suitable temperature for fruiting. Generally, it is advisable to prepare cultivation bags 50 days in advance when the local temperature drops below 18 degrees.
Spawn Production
1. Mother Culture
The commonly used media are PDA or PSA. MGYA medium can also be used (per 1000ml: peptone 1g, maltose 20g, yeast 2g, agar 20g), PDYA medium (per 1000ml: peptone or soybean peptone 1g, potato 300g, agar 20g, glucose 20g, yeast 2g), malt extract medium (per 1000ml: malt extract 20g, agar 15g, peptone 5g). Prepare test tube slants and inoculate for culture by conventional methods. Generally, it takes 8-10 days for mycelium to fully colonize the tubes. The latter three media can also accelerate mycelial growth rate.
2. Stock Culture and Cultivation Spawn
The medium formula is the same. Sawdust-bran medium can be used, with the formula: sawdust 73%, wheat bran 25%, sugar 1%, calcium carbonate 1%. Grains such as wheat, barley, corn, and sorghum can also be used as medium. Mix, process, bottle (bag), sterilize, inoculate, and culture by conventional methods. With the first medium, it generally takes 30-35 days for mycelium to fully colonize the bottles (bags). With the latter grain media, mycelium colonizes bags (bottles) faster, about 20 days.
Cultivation Site
King oyster mushroom cultivation sites mainly use shelf-type cultivation in mushroom houses. Bags are placed upright in a single layer. Shelf spacing is 50cm, with the lowest shelf 30cm from the ground. Generally, shelves are 4-5 tiers. The usable area of the mushroom house is %26Iuml of the mushroom house area. 60%%26Iuml. Number of shelf tiers, e.g., mushroom house 40m2%26Iuml. 60%%26Iuml. 4-tier shelves = 96m2. Each 1m2 can hold 100 bags. This mushroom house can cultivate 9600 bags.
The mushroom house should have ventilation windows that can be opened and closed, with some scattered light while avoiding direct sunlight. The mushroom site should be near a water source, with convenient transportation, facing south, in a clean environment with no pollution sources.
Cultivation Substrate Formulas
For cultivation substrate formulas, materials can be selected and mixed according to local conditions. Several formulas are listed below for selection.
1. Mixed wood chips 36%, cottonseed hulls 38%, wheat bran 24%, white sugar 1%, calcium carbonate 1%.
2. Mixed wood chips 23%, cottonseed hulls 23%, wheat bran 19%, cornmeal 5%, bean straw powder 28%, calcium carbonate 1%, white sugar 1%.
3. Mixed wood chips 23%, cottonseed hulls 38%, bean straw powder 15%, wheat bran 17%, cornmeal 5%, calcium carbonate 1%, white sugar 1%.
4. Mixed wood chips 37%, cottonseed hulls 38%, bean straw powder 15%, wheat bran 17%, cornmeal 5%, calcium carbonate 1%, white sugar 1%, lime powder 0.05%.
Making Cultivation Bags
The making of king oyster mushroom cultivation bags is similar to that of enoki mushroom cultivation bags. Bag specifications are generally 17%26Iuml.33-38%26Iuml.0.05cm. Polypropylene bags can be used for early autumn cultivation, and high-density low-pressure polyethylene bags are suitable for low-temperature winter periods.
Weigh the substrate materials according to the formula proportions, mix thoroughly, and adjust moisture content to about 68%. The bag material height is about 15cm, wet weight about 800g. Poke a hole in the center for inoculation and ventilation, then put on a ring and cotton plug, or fold the bag opening and tie with string. Sterilize with steam at 1.5kg/m2 pressure for 2 hours, or at normal pressure with steam at 100 degrees for 16 hours.
After the material temperature drops to room temperature, inoculate under aseptic procedures in an inoculation box (room). It is best to use wheat grain spawn or cottonseed hull spawn. 1 bag of spawn inoculates 40 bags. Let 1/3 of the spawn fall into the hole, and spread 2/3 of the spawn on the material surface. After inoculation, place upright on shelves in the spawn running room, culture in darkness, and maintain temperature at about 25 degrees.
If the bags are tied at the opening, when mycelium growth reaches more than 1/2 of the material, moderately loosen the bag opening to increase oxygen and promote mycelial growth.
Fruiting Management
After mycelium fully colonizes the bags, they can be moved to the fruiting room and placed upright on shelves for fruiting. Note that bags should not be placed too crowded, otherwise yield will be affected.
1. Master the Timing of Opening Bags
If mycelium is uneven, the economic traits of the mushrooms are poor. Opening bags when primordia form or small mushroom buds appear results in normal primordium differentiation and small mushroom development, uniform fruiting, and good economic traits. If bags are opened when fruiting bodies have already grown large, deformed mushrooms will appear inside the bags, and in severe cases the grown mushrooms will shrivel and rot. Therefore, the timing for opening bags in bag-cultivated king oyster mushrooms should be when mycelium knots to form primordia and small mushroom buds have appeared. Untie the bag opening and roll the bag film outward and downward to about 2cm above the material surface.
2. Control the Mushroom House Temperature Well
The mushroom house temperature directly affects primordium formation and fruiting body growth and development. When temperature is below 8 degrees, primordia are difficult to form, and even elongated mushrooms will stop growing, shrivel, turn yellow, and eventually die. When temperature remains above 18 degrees, differentiated fruiting bodies suddenly grow rapidly, quality declines, small mushroom buds begin to shrivel, and primordium differentiation stops. When temperature reaches above 21 degrees, primordia rarely appear, and already formed young mushrooms will also shrivel and die. Therefore, during the fruiting period, the mushroom house temperature should be controlled at 13-15 degrees. This way, fruiting is fast, mushroom buds are numerous, fruiting is uniform, and harvest can be done in about 15 days.
3. Control the Mushroom House Humidity Well
The air humidity in the mushroom house should be maintained at 85%-95%. If humidity is too low, fruiting bodies will shrivel, and primordia will dry and crack without differentiating. To increase air humidity, it is best to spray water upward with a sprayer. Never spray water directly onto the mushrooms, otherwise the fruiting bodies will turn yellow and quality will be affected, and in severe cases cause rot.
4. Regulate the Mushroom House Air Well
If ventilation is poor during the fruiting period, excessive CO2 concentration will cause deformed mushrooms, and if combined with high temperature and high humidity weather, it will also cause fruiting body rot. Therefore, during the fruiting period, good ventilation and air exchange conditions must be maintained in the mushroom house. Especially when plastic film is used for covering, the film should be removed 1-2 times daily for ventilation and air exchange. When mushroom buds appear in large numbers, promptly remove the plastic film, straighten the bag opening film to retain moisture, and increase ventilation.
Harvesting and Processing
1. Harvesting
Generally, harvest can be done about 15 days after bud emergence. The suitable harvest time is when the mushroom caps are about to flatten and spores have not yet been discharged. Harvest standards should be determined according to market needs: export mushrooms require cap diameter 4-6CM and stem length 6-8CM; domestic market has less strict requirements for mushroom body. After harvesting the first flush, culture for about 2 more weeks and the second flush can be harvested. The second flush mushrooms are smaller in shape, with shorter stems and lower yield. Under normal conditions, the first flush yield per bag is 120-150G. Total biological efficiency is 60%-70%.
2. Fresh Sales
Fresh mushrooms can be sold directly on the market, or packaged in plastic boxes with cling film for supermarkets. The shelf life of king oyster mushrooms is slightly longer than general mushrooms. Stored open in a 4-degree refrigerator for 10 days, they will not spoil; at 10 degrees they can be stored for 5-6 days; at 15-20 degrees they can also be kept for 2-3 days without spoiling.
3. Processing
King oyster mushrooms can be processed into dried products or made into canned goods.