Detailed Explanation of Off-Season Cultivation Techniques and Management Key Points for Shiitake Mushrooms

Shiitake mushroom (scientific name: Lentinus edodes), also known as winter mushroom, fragrant mushroom, northern mushroom, thick mushroom, thin mushroom, flower mushroom, and xianggu, is an edible fungus. The part generally eaten is the shiitake fruiting body. Fresh shiitake mushrooms, when dehydrated, become dried shiitake mushrooms, which are convenient for transport and preservation and are an important north-south trade good. Both dried and fresh shiitake mushrooms are widely used in Chinese cuisine. During cooking, dried shiitake mushrooms must first be soaked in water to rehydrate. In the vegetarian dish "three fresh delicacies," shiitake mushroom often appears as one of the "fresh" ingredients. In vegetarian meals, shiitake mushroom is also one of the important raw materials.

Morphological Characteristics of Shiitake Mushroom

The shiitake fruiting body grows singly, in clusters, or in groups, and the fruiting body is medium to slightly large. The cap diameter is 5-12cm, sometimes reaching 20cm; when young it is hemispherical, later becoming flat to slightly flat, with the surface being rhomboid-colored, light brown, dark brown to deep cinnamon, often with dark scales in the center, while the margin often has dirty-white hairy or floccose scales. The flesh is white, slightly thick or thick, fine and dense, with a fragrant aroma. When young, the margin is inrolled and has white or yellowish-white down, which disappears as it grows. Beneath the cap there is a partial veil, which later breaks to form an incomplete annulus. When old and mature, the cap margin rolls back and cracks. The gills are white, dense, adnexed, and of unequal length. The stipe is often off-center, white, curved, 3-8cm long and 0.5-1.5(2)cm thick, with fibrillose scales below the annulus, fibrous, and solid inside. The annulus disappears easily and is white. The spore print is white. Spores are smooth, colorless, elliptical to ovoid, 4.5-7×3-4μm, and reproduce by spores. The dikaryotic hyphae have clamp connections.

Key Points for Off-Season Cultivation Management of Shiitake Mushroom

Off-season cultivation of shiitake mushroom refers to the use of natural or artificial caves, air-raid shelters, and similar facilities for summer cultivation. However, most places do not have such facilities. Therefore, using ordinary greenhouses and cooling equipment for off-season cultivation will become the mainstream of production. Its technical key points are: 1. Cultivation facilities: In an ordinary edible mushroom greenhouse, after spring production is completed, remove the original mushroom bags, clean the interior of the greenhouse, check and repair the greenhouse film, spray an appropriate amount of chemicals for sterilization, then build fruiting racks at a layer height of about 25 cm, with each rack having about 5 to 7 layers, and connect and fix the top of the racks with thin bamboo poles or similar materials. After confirming everything is correct, fill the greenhouse with clear water. After the water seeps down, spread lime powder inside the greenhouse, and then the mushroom bags can be moved onto the racks. 2. Cooling equipment: At present, a patented product of a certain research institute, the "multi-functional water-temperature air regulator," has already been finalized for production. This equipment can be used for cooling production in summer and also for warming cultivation in winter, serving two purposes with one machine, with obvious energy savings and excellent results. In 2004, a demonstration application was carried out at our unit's edible mushroom base. During the spawn-running process in July to August, it could reduce the incubation temperature to 20-25 degrees C, and the use effect was very good. When warming is needed during low-temperature seasons, with only a small amount of coal, firewood, and other fuels, the air outlet temperature of this equipment can reach as high as 70 degrees C. Now, in addition to edible mushroom production, it has also been applied to vegetable greenhouse production. 3. Bag color conversion: Carry out spawn production and mushroom bag production according to conventional production procedures. After all spawn running is completed, stack the white mushroom bags in a "#" shape to a high level, and cover them with plastic film, straw mats, etc., so that while raising the temperature, by adjusting the covering of straw mats and plastic film and uncovering them at night, first it causes the white mycelium on the surface of the mushroom bags to lie down, and second it increases the temperature difference of the mushroom bags, prompting them to convert color as quickly as possible. 4. Temperature regulation and primordia induction: After color conversion is completed, the mushroom bags, after water supplementation treatment, can be moved into the greenhouse, all spaced about 5 cm apart and arranged in a single layer. Cooling treatment is carried out through the "multi-functional water-temperature air regulator." After 1-2 days, high-temperature stimulation is then applied. Combined with stimuli such as water use and light in the greenhouse, small mushroom primordia appear in about one week. After that, maintain conventional water use and minimize humidity differences as much as possible to ensure that primordia emerge continuously. The basic management indicators at this stage are: temperature maintained between 20-30 degrees C, with a temperature difference of about 10-15 degrees C; air humidity between 75%-95%. Since the cap of shiitake mushroom is relatively thick and it adapts to relatively large humidity differences, there is no need to worry that too large a humidity difference will cause death; by adjusting the covering on the top of the greenhouse, keep the light intensity inside the greenhouse at 300-1200 lux; moderate ventilation keeps the air inside the greenhouse relatively fresh. 5. Fruiting management: Because the plastic film of shiitake mushroom bags is relatively thick, the primordia cannot break through the bag on their own, so the plastic film must be cut manually. The method is: where primordia occur, use a small blade to cut open the plastic film, being careful not to damage the primordia. If management is careful, the plastic film can be cut in a circular opening around the primordium, which can avoid deformed mushrooms to the greatest extent. From the time the young primordia extend out, the fruiting management stage begins. At this stage, maintain: temperature at 20-28 degrees C, humidity between 75%-95%, light at about 500-1000 lux, and appropriate ventilation; when the cap diameter reaches more than 2 cm, a three-dimensional edible mushroom nutritional essence can be sprayed directly on the fruiting bodies. When the edge of the shiitake cap is still downward-rolled (copper-gong edge) but shows a tendency to expand, it should be harvested promptly. Note that, to a certain extent, the greenhouse temperature and "foliar fertilization" at this stage will determine the quality of the shiitake mushrooms. 6. Management of the next flush: The flushes of shiitake mushroom are relatively distinct. After one flush is harvested, the mushroom bags lose water rather seriously, so water supplementation and mycelium conditioning are needed before managing and harvesting the next flush. The commonly used method of water supplementation is: use existing ditches, canals, pits, or dig an earthen pit, line it with plastic film, arrange the mushroom bags inside, and when about 20 cm from the upper edge, lay a plastic film to form a concave shape. Fill the concave shape with water; after a certain pressure is formed, pour water into the pit containing the mushroom bags. After it is full, maintain for 24 hours, then drain the water, place the mushroom bags back on the fruiting racks, and refer to the above management. Generally, about 5 flushes can be harvested, with biological efficiency at about 80%.