Short-log sterilized-substrate cultivation techniques for reishi (Ganoderma lucidum)

Short-log sterilized-substrate cultivation is a new reishi cultivation technique that has developed rapidly in recent years. On average, each cubic meter of wood yields more than 20 kg of dried reishi, with high yields reaching more than 30 kg, an increase of 20% over conventional cultivation methods. The reishi is firm and thick in texture with a glossy surface, and its acid content is higher than that of bag-cultivated reishi. More than 90% of the product meets export requirements.

1. Cultivation season: Reishi is a medium-to-high temperature type fungus, and its yield is related to the tree species of the logs, the cultivation time and the cultivation technique. Inoculation time can be arranged from late October to December, or from early February to early March. Logs buried in the same year can all produce 2-3 batches of fruiting bodies. For logs inoculated before early to mid-December, the logs can be arranged and buried in March of the following year, and the yield in that year accounts for more than 70% of the total yield; for those inoculated in early February and arranged and buried in April, the yield in that year accounts for 55% of the total yield.

2. Raw materials: (1) All broadleaf tree species are suitable for cultivating reishi, but hard-textured broadleaf trees give higher yields and better quality, such as Castanopsis cuspidata, Castanopsis, oak, etc. If softer-textured wood is used for cultivation, the yield drops noticeably in the second year. Choose trees with a diameter at breast height of 8-20 cm; felling time should be arranged 3-5 weeks before inoculation, and about 1 week before inoculation the logs should be cut into sections and the branches trimmed. A moisture content of 38-45% is suitable. (2) The culture substrate uses mixed wood sawdust as the main raw material, with appropriate amounts of wheat bran, gypsum powder and other auxiliary materials added. The plastic bags use low-pressure polyethylene tubing with a thickness of 0.45-0.6 silk-meters (0.045-0.06 mm); the bag opening diameter comes in different specifications such as 14, 15 and 20 cm, and the bag length is 45-55 cm.

3. Production process flow: raw material preparation (felling of logs, cutting into sections) → bagging → tying the opening → sterilization → inoculation → mycelial culture → placing on beds and covering with soil → fruiting body management → reishi harvesting.

(1) Bagging: Cut the logs into 30 cm long sections, place them in bags, put sawdust culture substrate at the bottom and on the surface of the log sections, tie the opening, and use normal-pressure sterilization at 100°C for 12-14 hours.

(2) Inoculation: Move the sterilized bagged log sections into an inoculation room (or inoculation box) to cool, and inoculate strictly under aseptic conditions. Generally, 90-130 bottles of spawn are used per cubic meter of log sections. A larger inoculation amount can speed up mycelial colonization and reduce the contamination rate.

(3) Mycelial culture: Disinfect the culture room before placing the log-section bags inside. Stack the inoculated log-section bags in a "#" pattern, and culture them in the dark at an indoor temperature of 20-25°C. After 1 week, ventilate the culture room once a day at noon, and gradually increase the ventilation as the mycelial growth time extends. After about 60-70 days or more, the mycelium matures, and at this point soil-burial culture is carried out.

(4) Placing on beds and burying in soil: Choose a site that is sheltered from the wind and faces the sun, with good ventilation and convenient drainage, and build a shade shed. Before the inoculated logs enter the shade shed, clear weeds and pests, and after exposing the site to the sun for several days, make beds. The beds are 100-120 cm wide and 20 cm deep, with walkways left between them. Sprinkle insecticide and ant-killing pesticide on the bed surface, and choose a sunny day with an air temperature of 16-22°C to remove the bags and bury the logs.

(5) Fruiting body management: After the inoculated logs are buried in soil, keep the bed surface always moist, and control the shed temperature at 26-30°C. After 15-20 days, the primordia emerge from the soil. Keep the relative humidity at 85-90%. When the ventilation, temperature, humidity and light conditions are all suitable, the caps differentiate. Therefore, the key to fruiting body management is regulating the three factors of moisture, ventilation, and temperature and light.

(6) Harvesting: When the yellow-white growth ring at the edge of the cap disappears, the cap color deepens, the cap gradually thickens, and a large number of reddish-brown spores are released, it can be harvested. Stop spraying water before harvesting.