B ag-cultivated shiitake mushroom off-season soil-covering cultivation technique

B ag-cultivated shiitake mushroom cultivation has always adopted the spring-planting, autumn-and-winter-mushroom model, with the fruiting period mainly concentrated from October to March of the following year, while April to September is a blank period for mushroom production. The total amount of fresh mushrooms cannot meet the growing consumer demand at home and abroad. In recent years, Zhukou Town, Qingyuan County, has explored a set of new techniques for off-season soil-covering cultivation of bag-cultivated shiitake mushrooms, achieving very good economic benefits and being very suitable for mushroom farmers' large-scale production. The technique is introduced below for reference by colleagues only:

1 Advantages

The advantages of off-season soil-covering cultivation of shiitake mushrooms can be summarized in the following 5 aspects:

1.1 Year-round nature

Compatible with the conventional cultivation (winter mushrooms) in Zhukou Town, it can achieve year-round production;

1.2 Labor-saving and material-saving

The mushroom shed does not need to be built with ground racks; after soil covering, the entire cultivation and production period can save the processes of water injection and soaking;

1.3 Short production cycle, quick returns, high benefits.

1.4 Excellent mushroom quality

The shiitake mushrooms produced have a round and neat cap shape and thick flesh, {R suitable for fresh mushroom production;

1.5 Change the environmental conditions of the mushroom shed, reduce the overwintering base of pests and diseases, and reduce rotten logs;

2 Cultivation techniques

2.1 Variety selection and seasonal arrangement

The shiitake mushroom varieties used for off-season soil-covering cultivation have special requirements, namely high fruiting temperature, strong stress resistance, high yield, and excellent mushroom quality. In Qingyuan County, currently applicable varieties provided by the county research center include Wuxiang No. 1, L26, 931, cr04, Tingxuan 18, etc. The cultivation season is generally arranged in winter and spring (from the 12th lunar month to the following 1st lunar month) for making spawn logs, with soil covering from April to June and fruiting from May to October.

2.2 Bagging and spawn running

2.2.1 Culture medium formula and substrate selection The substrate generally uses a conventional formula: sawdust 78%, wheat bran 20%, gypsum and brown sugar 1% each, pH natural. Each bag is filled with 1.7 kg of wet material (15-54 tube bags). The substrate is required to be fresh and free of mildew, and all ingredients must be added in sufficient amounts according to the formula requirements.

2.2.2 Sterilization and inoculation Bagging should be firm, and sterilization should be thorough. Maintain 100°C for no less than 12 hours. Adopt "open" inoculation technology.

2.2.3 Spawn running The spawn running stage is basically the same as conventional methods. Pricking holes for aeration should be timely. About 7 days after the mycelium has covered the entire bag, enlarge the holes for major aeration, pricking 50 holes per bag. At the same time, spread out the mushroom logs and appropriately increase light to promote color change of the logs. Generally, after 80-110 days of spawn running, soil covering can be carried out (for early inoculation, the spawn running time is slightly longer due to lower temperatures).

2.3 Selection of fruiting site and construction of the mushroom shed

The fruiting site should be selected in fields with flat terrain, sufficient water source, good water quality, relatively low water temperature, convenient drainage and irrigation, sanitary surrounding environment, short solar radiation duration, large day-night temperature difference, and no termites. The mushroom shed is 2.5 m high, covered on the support frame with fir branches or reeds, Miscanthus floridulus, etc., and the surroundings of the shed are enclosed tightly with rice straw and Miscanthus floridulus to create a mushroom shed environment with little light, coolness, and good ventilation.

2.4 Bed preparation and bed surface treatment

Prepare the beds according to the length of the mushroom logs and the actual conditions of the shed, making maximum use of the shed. The bed width is generally 1.2-1.3 m, allowing 3 mushroom logs to be placed in parallel. The bed ditch is 0.5 m wide and 30-40 cm deep. The bed surface should be leveled or slightly turtle-backed, and drainage ditches should be dug around it to facilitate drainage. After preparing the bed, first spread a layer of quicklime on the bed surface, then spread a thin layer of fine sand on the lime, and spray the bed surface and around the shed once with 80% dichlorvos 600-fold solution for insect control (this work is generally carried out 7-10 days before placing the mushroom logs). Cover the bed surface with an arched frame (or use an arched plastic greenhouse), disinfect with formalin or aerosol disinfectant, seal for 7 days, and then the mushroom logs can be placed.

2.5 Soil preparation and treatment

The soil used for covering requires loose texture, no insect eggs, no clumping, and good moisture retention. Semi-sandy mountain topsoil is suitable, and burnt soil is optimal. Generally, about 8 loads of soil are used per thousand logs. Soil treatment should be done before covering, and this is a very key technical step. The specific method: 7-10 days before preparing to cover with soil, collect enough covering soil according to the number of mushroom logs, mix in lime at 1%-2% of the soil volume, pile it up, spray with dichlorvos, cover well with plastic film, then disinfect with formalin or aerosol disinfectant, seal for 7 days to carry out insect removal and sterilization.

2.6 Color change management of the spawn logs

When the mycelium has fully covered the bags for about half a month, they can be successively moved on sunny days into a pre-prepared shade shed for spawn running and "log conditioning." After 10 days of "log conditioning," choose weather with a stable temperature of 20-25°C, use a sharp blade to cut and remove the bags, place them flat on the bed surface one bag closely against another, and cover the bed surface with plastic film so that the spawn logs can naturally change color under suitable temperature conditions. Handle them gently during operation to avoid damaging the mycelium or causing premature fruiting. During the color change period of the spawn logs, all shiitake mushrooms growing on the underside of the logs should be picked clean to prevent rotting after soil covering.

2.7 Soil covering

After the spawn logs have naturally changed color, fill the gaps between the logs with the pre-prepared mountain topsoil or burnt soil. About 1/4 of the total area of the spawn logs on top need not be covered with soil. Note: if there are mushroom buds on the spawn logs, the buds should face upward and be exposed above the bed surface, or be removed cleanly before soil covering; moldy and rotten logs should be dealt with promptly.

2.8 Fruiting management

Throughout the fruiting management period, the management technical measures all revolve around cooling, ventilation, and moisture retention, especially cooling during high-temperature periods. After soil covering, cover with film for 2-3 days to stimulate complete color change of the spawn logs. When the temperature is high, the film can be lifted once at noon for ventilation. After that, do not cover with film continuously, but to prevent rain, fix the plastic film on the bed surface while lifting its surroundings. After about 5-20 days, a large number of mushroom buds can be seen forming. After budding, ventilation should be strengthened, and the soil should be kept moist. Generally, water can be sprayed once every other day. To prevent soil from sticking to the mushroom bodies, mist spraying is best. The water used should be sanitary and clean, and spraying sewage or muddy water is strictly prohibited to prevent mud, sand, impurities, etc. from contaminating the shiitake mushrooms and affecting quality. A small amount of water is generally kept in the bed ditch, but when the temperature is above 28°C, the method of irrigating during the day and draining at night can be used to cool down and increase the temperature difference. After the first flush of mushrooms is harvested, stop spraying water for 4 days and cover with film for spawn running. After 1 week, increase the amount of water spraying, carry out temperature difference stimulation and alternate wet-dry management, and combine with regulating external conditions such as light and ventilation to promote the reoccurrence of mushroom buds. Generally, 4-6 flushes of mushrooms can be harvested during the entire cultivation period.

2.9 Harvesting

Harvesting should be carried out in different @#@136@#@ ways. For fresh-keeping mushrooms, harvest when the veil has not broken; for dehydrated and dried mushrooms, harvest when the mushroom bodies are 80% mature. Because the temperature is high, in order to ensure mushroom quality, harvesting should be done 3 times a day in the morning, noon, and evening. Note: if the harvested fresh mushrooms have a small amount of soil on the stipes, the soiled stipes should be trimmed off on the spot with a knife or cut off to avoid contaminating other mushroom bodies and reducing shiitake mushroom quality.