Detailed Explanation of the Key Points of Linden Log Lingzhi (Reishi) Cultivation Technology

Linden log lingzhi cultivation technology is one of the lingzhi cultivation techniques. At present, artificial lingzhi cultivation includes linden log cultivation and substitute material cultivation. So what exactly is linden log lingzhi cultivation technology? Let's take a look!

1. Seed selection

Select suitable lingzhi varieties as the cultivated varieties, such as South Korea Lingzhi No. 1, No. 2, Taishan Lingzhi No. 1, etc.;

Select suitable tree species and cut them into sections as the cultivation substrate, such as tree species of Fagaceae, Hamamelidaceae, etc.

2. Cultivation process

1. Time arrangement

Generally arranged from early December to late January of the following year. During this period, the temperature is low and there is little rain, so the inoculation survival rate is high.

2. Drilling holes and bagging

Cut fresh logs into short linden logs 30 cm long, use a scraper to smooth the needle-like residue around the cut surface to avoid puncturing the bag film, then use an electric drill or bench drill to make 3 holes with a diameter of 1.8 cm and a depth of 3 cm, smooth the holes and put them into low-pressure polyethylene bags with a folded width of 20-30 cm and a thickness of 0.005 cm, with the holes facing the bag wall, 2-4 sections per bag, moderately tight, gather the bag opening and tie it tightly with rope. Linden logs with too large a diameter are split into two halves, then drilled and bagged. When the linden logs are too dry, use soaking in water or adding water inside the bag to increase the water content.

3. Sterilization

After stacking, introduce steam through a steam furnace for sterilization. When stacking the fungus bags, leave gaps every two or three layers, or use one horizontal layer and one vertical layer, that is, stack them in a “well” shape.

After the temperature reaches 100 degrees, keep it uninterrupted for 10 hours. If water needs to be added midway, it is best to prepare boiling water. Throughout the process, use a high fire at the beginning to make the temperature rise quickly to 100 degrees, and use a fierce fire in the last 1-2 hours to finish thoroughly. After sterilization is completed, let it sit for 3-5 hours, and only gradually open the furnace door after the temperature inside the furnace drops below 70 degrees, take out the bags and place them in a cooling room for fumigation and cooling with disinfectant. When moving and stacking the fungus bags, use suitable plastic baskets, handle them gently, and remember not to damage the bag film. If high-pressure sterilization is used, use polypropylene bags for bagging, keep the pressure at 0.137 MPa for 1.5-2 hours, and let it drop naturally.

4. Inoculation

Place the cooled material bags into an inoculation box or inoculation room, inside an inoculation hood, and disinfect and sterilize again with a fungicide fumigant or an oxygen atom environmental sterilizer. Then operate with two people: one person uses a 45-watt electric soldering iron to burn through the bag film at the position of the linden log hole, and the other person uses long tweezers to pick up block-shaped spawn and fill it into the hole, then hands it back to the hole-burning person to seal and stick with special adhesive tape. If the cultivated spawn is expanded and cultured in plastic bags, during inoculation you can wear sterile finger cots and directly break off fungus blocks from the cut at the bottom of the bag and fill them into the holes. This is fast, flat, and effective. The fungus blocks must be fresh, with a spawn age within 25 days.

5. Spawn-running management

The spawn-running room should be strictly disinfected in advance. After pest control, place the fungus bags on shelf layers, or stack them vertically and horizontally in layers on the ground with backing boards or foam plastic boards, and control the temperature at about 25 degrees so that the hyphae can quickly colonize and spread. The growth speed of hyphae in linden logs is fastest in the axial direction, second in the transverse direction, and slowest in the tangential direction, and the approximate growth speed ratio of the three is 4:1:0.5.

Therefore, after inoculation, culture at a suitable temperature to promote the hyphae to quickly grow from the axial direction and transverse direction over the entire linden log surface and extend into the phloem, cambium, vascular bundles, etc. Keep the air in the room fresh, open windows at noon every day for ventilation and air exchange, control the relative air humidity below 70%, and finely spray 3% Lysol once a week to prevent the breeding of miscellaneous fungi.

As the amount of growing hyphae increases, the oxygen in the fungus bag decreases and water droplets on the bag wall increase. When the hyphae form a fungus covering on the cross-section, combine with indoor spray disinfection, slightly open the bag opening, remove moisture, increase oxygen, keep the linden log surface in a slightly dry state, and promote the hyphae to extend into the xylem and spread in the tangential direction, accumulating more nutrients. This moisture-discharging, oxygen-increasing, and growth-promoting management is carried out once every 10 days.

If water accumulates at the bottom of the bag, use a sterilized syringe to draw out the accumulated water, and seal the needle hole with transparent tape.

6. Building sheds and burying logs

A. Land preparation and shed building: Choose an open plot with good ventilation, convenient drainage and irrigation, and fertile, slightly acidic land as the lingzhi field. After deep plowing and sun exposure, make beds in an east-west direction, with a bed width of 1.5 m, a height of 20 cm, a walkway between beds of 30 cm, and open drainage and irrigation ditches 20 cm around, and spread insecticide to prevent pest damage. Build 1 plastic shed for every 3 beds, with a shed height of 2 m, and build a flat shed 20 cm from the shed top, covered with a shade net with 80% shading. It can also be adapted to local conditions according to altitude, terrain, production scale, geographical conditions, etc., by building medium sheds, small arched sheds, and under-forest planting.

B. Placement of fungus material: When the hyphae in the fungus bag have grown all over the linden log, reddish-brown fungus covering appears on the cross-section, the surface of the fungus material has a elastic feel, and a small amount of fungus material shows primordium protrusions, choose a sunny day to take the fungus material out of the bag, open shallow ditches on the bed, place the fungus material horizontally into the ditches with the inoculation holes facing up, 4 sections per row, row spacing 8-10 cm, cover with soil 2 cm above the fungus material, press slightly flat, water so that the soil water content reaches about 60%, and keep it moist, but avoid water accumulation.

7. Fruiting body management

A. Early stage: After the fungus material is buried in soil, the temperature is relatively low, so focus on heat preservation. During the day, thin out the covering on the shed top to receive light and increase ground temperature. Keep the temperature in the shed above 22 degrees. After about half a month, the primordia emerge from the soil surface. Pay attention to ventilation and air exchange, ventilate once every 2-3 days at noon on sunny days, and control the relative air humidity at about 85%.

B. Middle stage: The temperature rises and the temperature difference is relatively large. During the day, pay attention to cooling, thicken the covering on the shed top, and control the temperature at about 28 degrees. At this time, the fruiting bodies grow relatively quickly, so increase ventilation. The shed film around can be rolled upward to about 6-10 cm from the bed surface to prevent carbon dioxide accumulation and produce deformities. Control the relative humidity at 90%-95%, and often spray into the air to maintain moisture. At night, lower the film to reduce the temperature difference between day and night. After each flush of lingzhi is harvested, water heavily for 2 days to promote the recovery of hyphae growth and the recurrence of primordia.

C. Late stage: The temperature gradually decreases, and the air also tends to be dry. Focus on heat preservation. During the day, thin out the covering to increase the temperature in the shed, and increase the frequency of spraying. During ventilation, ventilate from the southeast direction to prevent attacks from the northwest direction. Through careful management, strive for more lingzhi and good lingzhi.

8. Timely harvesting

When the lingzhi cap is fully expanded, the light white or pale yellow at the edge has basically disappeared, the cap begins to become leathery and appears brown, and begins to release spores, after collecting spores in bags for 7 days (the spore collection method is introduced below), it should be harvested in time. If not harvested at this time, it will affect the formation of the second flush of lingzhi fruiting bodies. When harvesting, use a sharp small knife to cut at 0.5-1 cm of the stipe. Never pull it out together with the fungus skin, so as to avoid the spread of insect pests and diseases, and at the same time the second flush of lingzhi fruiting bodies will also be difficult to form. After harvesting, the culture material, after several days of rest, should be sprayed once with soybean milk water, and after several days the second flush of lingzhi fruiting bodies will grow. Clean the harvested lingzhi, place them on plastic sheeting or bamboo curtains to dry in the sun, or use a dryer to dry them.

9. Other management

Temperature: Lingzhi belongs to high-temperature fungi. The mycelium growth range is 15-35 degrees, suitable at 25-30 degrees. The mycelium can endure low temperatures below 0 degrees and high temperatures of 38 degrees. The temperature for primordium formation and growth and development of fruiting bodies is 10-32 degrees, and the most suitable temperature is 25-28 degrees;

Moisture: Different growth and development stages have different water requirements. During the mycelium growth stage, the water content in the culture medium is required to be 65%, and the relative air humidity is 65%-70%. During the fruiting body growth and development stage, the relative air humidity should be controlled at 85%-95%;

Light: Lingzhi is very sensitive to light during growth and development. Light has an inhibitory effect on mycelium growth. Practice has proved that when the light is 0, the average daily growth speed is 9.8 mm. When the light intensity is 50 LX, it is 9.7 mm, and when the light intensity is 3000 LX, it is only 4.7 mm. Therefore, strong light has a significant inhibitory effect on mycelium growth;

pH: Lingzhi likes to grow in a slightly acidic environment, requiring a pH range of 3-7.5, with pH 4-6 being the most suitable.