Detailed Guide to Oyster Mushroom Cultivation in Greenhouses: Strain Selection and Treatment Are Key

AbstractSite selection: Choose mountain land or forest clearings that are sheltered from the wind, face the sun, and are close to a water source. Site treatment: After deep plowing the soil, carry out sterilization treatment, then maintain ventilation and air permeability. Raw materials: Choose soybean stalks, corn stalks, rice straw, etc., and use them for mixing after treatment. Formula and sowing method: Make a reasonable culture medium formula according to the nutritional needs of oyster mushrooms, then spread the spawn on the mushroom bed. Strain selection and treatment: Choose suitable strains according to the sowing season. Strains need to be sown promptly and should not be stored.

I. Site Selection

1. Oyster mushrooms generally grow in flat areas with good drainage that are sheltered from the wind and face the sun. Mountain land and forest clearings close to a water source are growing environments that oyster mushrooms like very much.

2. Oyster mushrooms like sunlight but are afraid of being scorched, so it is best to plant them in a place that can block the sun and provide shade.

3. When growing oyster mushrooms indoors, in greenhouses, or in open fields, the terrain should not be too dry. When building a mushroom-growing site, try not to choose places with strong wind flow and poor moisture retention, especially hillside areas with serious soil erosion. On the contrary, low-lying areas with too much water are also not conducive to the growth of oyster mushrooms.

4. The direction of greenhouses or warm sheds should be east-west, and they should be built according to the requirements of a bed frame width of 1.2 m, a shelf distance of 45 cm-55 cm, and an aisle width of 65 cm-70 cm.

II. Site Treatment

After determining the site, clean it. If conditions permit, the soil can be deeply plowed. If bed frames are used to grow oyster mushrooms, the frames should be completed first, then the planting site should be sealed two days before sowing for sterilization treatment. Use 10 ml/m3 formaldehyde mixed with 7 g potassium permanganate or 15 g-20 g/m3 sulfur for fumigation for one to two days. During this period, an appropriate amount of water should be sprayed to achieve the effect. Before adding materials, first open the sealed space for ventilation to discharge toxic gases.

III. Raw Material Selection and Treatment

1. Raw material selection

(1) The sources of raw materials for oyster mushrooms include rice straw, sawdust, distillers' grains, corn stalks, tree leaves, waste paper, corn cobs, soybean stalks, cottonseed hulls, waste cotton, crop straw, and by-products of industry and sideline production, among others. There is a very wide variety to choose from.

(2) When choosing raw materials, try not to use moldy or spoiled ones. Even materials stored from the previous year need to be fully exposed to the sun for two to three days before use. Only by choosing fresh raw materials can high-quality oyster mushrooms be grown.

(3) In Northeast China, oyster mushrooms grown with corn cobs as the raw material not only have the best yield and quality, but also have low cost, followed by sawdust and soybean stalks.

(4) Most oyster mushrooms grown in Shandong, Henan, and other places use cottonseed hulls as the raw material, and the average yield is higher than that of the entire Northeast region. Therefore, adapting measures to local conditions can bring greater economic benefits into play.

2. Raw material treatment

Raw materials need to be processed first before mixing. For example, corn cobs need to be crushed into granules, kept at about the size of peas. In addition, soybean stalks, corn stalks, rice straw, etc. should be directly cut with a sickle into small sections of 6 cm-8 cm. Sawdust, distillers' grains, etc. can be mixed directly.

(1) Soybean stalks and corn stalks

Soak fully in 1.5% lime water for 15-20 minutes, scoop them out with a container and pile them together, and keep them sealed for 12-24 hours. Water an appropriate amount during the waiting period. Once the soybean stalks and corn stalks have absorbed water thoroughly, they can be used for mixing.

(2) Rice straw

Soak fully in 2% lime water for 12-24 hours, scoop out with a container, then rinse clean with clear water, keeping the pH between 7.5-8 and the moisture content at 60%-65%. When the water control standard is that no water drips when held with both hands, it can be used for mixing.

IV. Formula Selection and Sowing Method

1. Formula selection

A suitable culture medium formula must be reasonably proportioned according to the nutritional needs of oyster mushrooms, which not only saves raw materials but also makes use of the nutrients in the culture medium.

(1) Mix selection

According to the actual situation, choose any one of the following formulas for mixing.

Formula 1: You may choose 90% corn cobs, 0.2% monopotassium phosphate, 0.3% magnesium sulfate, 1% superphosphate, 1.5% gypsum, 5% cornmeal, 2% lime, and 60% moisture content as the mix.

Formula 2: You may choose 39% rice straw (soaked), 1% superphosphate, 20% rice bran, 2% lime, 1% gypsum, 39% sawdust, and 65% moisture content as the mix.

Formula 3: You may choose 45% soybean stalks, 1% gypsum, 2% lime, 45% sawdust, 0.3% urea, 0.2% magnesium sulfate, 5% cornmeal, 1.5% superphosphate, and 60-65% moisture content as the mix.

Formula 4: You may choose 90% soybean stalks, 1.5% superphosphate, 1% gypsum, 6% cornmeal, and 65% moisture content as the mix.

Formula 5: You may choose 90% rice straw (soaked), 0.2% magnesium sulfate, 1.5% lime, 2% superphosphate, 0.3% urea, 6% cornmeal, and 65% moisture content as the mix.

(2) Treatment method for corn cobs (that is, Formula 1): Process according to the formula above. First, stir lime, cornmeal, gypsum, etc. together evenly, then add them to corn cobs crushed with a grinder, and stir again. Superphosphate, magnesium sulfate, monopotassium phosphate, etc. should be diluted and dissolved by adding water in multiple portions, then mixed into the culture material. In the initial stage, the pH value should be regulated to 10-14. After sealing for 1-2.5 hours, it should later drop to 8.5-9. The moisture should preferably be regulated at 60%-65%.

2. Sowing method

(1) First spread a 2 cm layer of river sand, and spray an appropriate amount of 2% potassium permanganate once.

(2) Then make a mushroom bed 60 cm-80 cm wide, and scatter one-fifth of the spawn, with slightly more in the middle.

(3) Next spread a 5 cm thick layer of culture material. According to the ratio of two layers of material and three layers of spawn or three layers of material and four layers of spawn, spread 5 cm-20 cm as appropriate. Properly press the culture material so that its middle is high and its left and right sides are low, then spread a layer of plastic sheeting, press the surroundings firmly with sandy soil, and finally cover it well with shading material.

No matter which cultivation method is adopted, more spawn needs to be scattered around to prevent contamination by foreign bacteria. In addition, the moisture and pH ratio of the spawn must be strictly controlled, as this affects the final yield of oyster mushrooms. 

V. Strain Selection and Treatment

1. Strain selection

(1) Types of strains

In early spring, choose medium-temperature and medium-high-temperature strains such as Nongxin No. 1, Xinping 1012, Jiuhua 191, and Huiping, etc. In summer, choose Phoenix mushroom, elm yellow mushroom, HP1, etc. In autumn and winter, choose Aohei, A2, Meiwei 5.39, German No. 2, Hypsizygus marmoreus, etc.

(2) Strain quality

If the mycelium is white in color, dense and robust, connected from top to bottom, with downy fuzz growing on the upper surface, not dry or shrunken, without accumulated water, with a small amount of primordia of fruiting bodies, and if it is dug out of the bottle without falling apart, it can be judged to be an excellent strain.

If the mycelium is thin and yellowish, sparse and weak, dry and shrunken, with accumulated water and a large number of fruiting body primordia, such a strain is generally already aged and cannot be used. If yellow, green, gray, or other miscellaneous colored colonies even appear in the bottle, it can be judged that the strain has been seriously contaminated and also cannot be used.

2. Strain storage

Poor-quality strains or planting contaminated strains on a large scale will cause foreign bacteria to spread, sharply reduce yield, and cause heavy losses. Therefore, strains should be sown promptly. If they must be stored, in order to avoid contamination and deterioration of the strains caused by sunlight exposure or moisture on cloudy and rainy days, they can be placed in a cool storage room and kept properly.

3. Treatment method

Prepare 0.2% potassium permanganate as well as tools such as basins, plastic sheeting, and tweezers, and begin digging out the spawn. Select suitable spawn and place it on a table board. Clean the outer bottle wall and seal with 0.2% Lysol solution. After opening the seal, discard the surface mycelial skin and do not use it. Dig the rest into spawn blocks the size of peas. If the spawn is in plastic bags, wash it with 0.2% Lysol and break it apart. After digging out the spawn, cover it with a layer of newspaper, and then it can be sown. In addition, minimize personnel entry and exit at the site, and do not expose it to wind or sun, and do not let it touch water, in order to prevent infection by foreign bacteria.