Detailed Explanation of Key Technical Points for Outdoor Mushroom Bed Cultivation and Management of Oyster Mushrooms
Oyster mushroom (scientific name: Pleurotus ostreatus; also known as hiratake, rough-skinned oyster mushroom, oyster mushroom, black peony mushroom, and called Xiuzhen mushroom in Taiwan, China) is a species in the family Pleurotaceae, order Agaricales, under the Basidiomycota, and is a fairly common gray edible mushroom. Traditional Chinese medicine holds that oyster mushroom is warm in nature and sweet in taste. It has the effects of dispelling wind and scattering cold, and soothing the sinews and invigorating the collaterals. It is used to treat conditions such as waist and leg pain, numbness of the hands and feet, and blocked meridians. The protein-polysaccharide bodies in oyster mushroom have a strong inhibitory effect on cancer cells and can enhance the body's immune function.
Oyster mushroom is a tetrapolar heterothallic edible fungus. The life history of oyster mushroom is similar to that of many higher basidiomycetes, producing basidiospores from mature fruiting bodies. The basidiospores are ejected from the gills of the mature fruiting body, and upon encountering a suitable environment they grow germ tubes, initially multinucleate, and soon form septa, with each cell relatively flat, orderly and dense, without the “yellow tip” phenomenon; after several days of full growth, old mycelial skin readily appears, and the mycelial skin is relatively tight and hard.
Wide-temperature species such as Pleurotus cornucopiae: aerial hyphae fewer than the previous three types, growing flat, without “yellow tips”. After fully covering the slant, mycelial skin readily forms; the mycelial skin is soft, elastic, and very difficult to cut apart.
Mycelium. The mycelia of all artificially cultivated species are white, pure white and dense on agar medium, with varying amounts of aerial hyphae. Pleurotus ostreatus and Pleurotus sapidus: aerial hyphae dense, and in the later stage of culture yellow secretions often appear on the aerial hyphae, thus producing the “yellow tip” phenomenon. No mycelial skin is formed.
Fruiting body. The common morphological features of the fruiting bodies of all species in the genus Pleurotus are: decurrent gills and lateral stipe. The main bases for taxonomically distinguishing different species are host, cap color, season of occurrence, structure within the hymenium, and spores, etc. Pleurotus ostreatus and Pleurotus sapidus: cap diameter 5-21 cm, grayish white, light gray, tile gray, bluish gray, gray to dark gray, with a relatively rounded cap margin. Stipe relatively short, 1-3 cm long, 1-2 cm thick, often with fuzz at the base. Both the cap and stipe are relatively soft. Spore print white, some varieties slightly tinged with lotus pink. Fruiting bodies often grow in clusters, even overlapping.
Cultivation and management techniques for outdoor mushroom beds of oyster mushroom
1. Mushroom bed selection
Choose open ground or cultivated land that is sheltered from wind and facing the sun, close to a water source, well-drained, and with few hazards from poultry and livestock, or dig mushroom beds in the clearings between trees in an orchard. The mushroom bed should be oriented north-south, about 10 cm deep, 1 m wide, and any length. Leave a cement ridge about 10 cm wide or a small ditch in the center of the bed. After digging the mushroom bed, disinfect it with 1% lime water or lime powder. Two, preparation of culture material
Oyster mushroom culture materials are abundant in resources; cottonseed hulls, wheat straw, rice straw, sawdust, sugarcane bagasse, corn cobs, and rapeseed hulls can all be used for cultivation, but cottonseed hulls give the highest yield and good economic returns. For the preparation of cottonseed hull culture material, generally use 96% dry, fresh, mold-free cottonseed hulls, first sun-dry for 1-2 days, pile on a cement yard, add 2% gypsum, 2% superphosphate, and then add 0.02% carbendazim or thiophanate pesticide to prevent contamination by foreign fungi during cultivation. On this basis, a small amount of urea may also be added, but not too much, otherwise the mycelium grows well while fruiting body development is poor, and the yield is instead not high. After mixing the culture material evenly, add water while mixing, so that the cottonseed hulls absorb enough water and nutrient solution. Generally, add 60-75 kg of water per 50 kg of cottonseed hulls; squeeze the culture material tightly by hand, with water dripping from between the fingers as the standard, at which point the water content is about 68%. Since many foreign fungi prefer a slightly acidic environment, in production the culture material is often prepared to be neutral or slightly alkaline to inhibit the growth of foreign fungi. Three, sowing and cultivation
After the material is mixed, it can be spread into the mushroom bed. Generally spread 10-15 kg of material per square meter, about 10-15 cm thick. Spread it well and level it, then inoculate with oyster mushroom spawn; the inoculation amount is 4-6 bottles per square meter; when sowing, spread one layer of material, then one layer of spawn, and generally 2-3 layers is suitable. After sowing, gently pat the spawn and culture material firm with a wooden board into a turtle-back shape. Cover the material surface with old newspapers and plastic film to keep warm and moist, and finally cover the film surface with a straw curtain. Four, bed surface management
After the bed surface is covered with plastic film and straw curtain, the oyster mushroom mycelium will grow rapidly within the material. Generally after 20-30 days the mycelium will have covered the entire culture material. When the mycelium has reached the bottom of the bed, it indicates that the mycelium on the material surface has matured. When the mycelium begins to form piles of small yellow beads like millet grains on the material surface, it indicates that the fruiting bodies have begun to form. At this time remove the newspapers; when more than 60% of the bed surface has small mushroom buds, the plastic film can be raised, using bamboo strips arched on both sides of the bed and covered with plastic film on top. Since oyster mushroom is an aerobic fungus and requires scattered light during the fruiting body development stage, after raising the film, uncover it for ventilation 1-2 times daily. When the mushroom caps grow to the size of a 5-fen coin, irrigate the bed ditch or spray water on the bed surface several times in small amounts, so that the air humidity within the bed is maintained at 80-90%, and the mushroom buds will grow rapidly and soon become clusters of oyster mushrooms. During the fruiting body growth stage, if small blue-green or yellow-black spots appear on the bed surface, these are foreign fungi. Immediately increase the frequency of ventilation and extend the ventilation time, then cover with quicklime or irrigate the affected spots with 0.2% carbendazim solution. Five, harvesting
When the oyster mushroom fruiting body color turns grayish white or dark gray and the cap is glossy, it can be harvested. Oyster mushroom should be harvested in time; if not harvested in time, it will shed spores, that is, eject a large number of spores to reproduce, and the fruiting body will quickly age, thereby losing its edible value. When harvesting, use a sharp knife to cut off the entire cluster of fruiting bodies, or twist the fruiting body to harvest, to prevent the oyster mushroom from breaking apart or the material surface from being pulled loose. After harvesting the oyster mushroom, the mushroom bed should have the film uncovered for ventilation, and watering should be stopped for 1-2 days, then cover with film to keep warm and moist, and proceed to the management of the next flush of mushrooms.