Detailed Explanation of Key Techniques for Cultivating Lingzhi with Three Harvests a Year

Lingzhi is a medicinal fungus. With the development of modern medicine, its medicinal value is continuously being discovered, and thus artificial cultivation has attracted widespread attention. Its high-yield cultivation techniques are neither as complex as some people think nor as simple as some people think. As long as appropriate technical measures are taken, achieving high yields is still hopeful. From years of practice, to achieve three harvests a year, the following points generally need to be mastered:

1. Reasonably arrange the production season

Lingzhi is a high-temperature, constant-temperature fruiting fungus. During its growth and development process, it requires relatively high temperatures, with 26°C-28°C being optimal. The optimum temperature for mycelial growth is 28°C; below 27°C growth is noticeably inhibited, and above 30°C the mycelium may age and autolyze. The optimum temperature for fruiting body growth is 24°C-28°C; below 18°C it cannot grow normally. The primordium formation and fruiting body growth stages of lingzhi do not require temperature fluctuation stimulation; excessive temperature differences can produce deformed lingzhi. Using this as a reference, in Anhui Province only the temperatures from May to October can meet the needs of lingzhi growth and development. From the perspective of three harvests a year, the final harvest period should be in early September. Calculating backward from this, mother spawn should be propagated in early March, stock spawn in early April, cultivation inoculation in early May, and the three harvests can be taken in early July, early August, and early September.

2. Select good varieties according to local conditions

There are many types of lingzhi. Based on morphology and color, they can be divided into six types: red lingzhi, black lingzhi, green lingzhi, white lingzhi, yellow lingzhi, and purple lingzhi. The commonly cultivated variety is red lingzhi. Among red lingzhi, good varieties include: Xinzhou, Huizhou, Korean, Taishan No. 1, Dabie Mountain lingzhi, etc. Xinzhou lingzhi has strong stress resistance, large and thick caps, good commercial quality, and high yield, and is an excellent variety for export to earn foreign exchange. Korean lingzhi spawns quickly, fruits early, has large and uniform caps, and relatively high yield. Taishan lingzhi grows rapidly and is suitable for substrate cultivation, but its yield is somewhat lower. Dabie Mountain lingzhi has large caps and deep color, and is more suitable for log cultivation. Therefore, each locality should determine the variety according to local production conditions (for example, whether substrate cultivation or log cultivation is used) and production purpose (for example, whether for export or domestic sale). If substrate cultivation is adopted to achieve three harvests a year, Korean lingzhi can be selected.

3. Correctly select substrate formulas

Lingzhi is a wood-rotting fungus. Suitable tree species include oak, wild jujube, Chinese tallow, elm, poplar, etc. Substrate cultivation should mainly use sawdust from suitable tree species, appropriately combined with some cottonseed hulls, corncobs, etc. Commonly used formulas can be selected as follows:

1. Mixed wood sawdust 83%, corn flour (or wheat bran) 15%, gypsum powder 1%, sucrose 1%.

2. Cottonseed hulls 39%, mixed wood sawdust 39%, corn flour (or wheat bran) 15%, gypsum powder 1%, sucrose 1%.

3. Corncobs 78%, bran 15%, gypsum 2%, sucrose 1%, superphosphate 1%, urea 0.5%, lime 2.5%.

The older the sawdust, the better, but it must not be moldy. Bran can also be replaced with rice bran, and gypsum can be replaced with calcium carbonate. The material-to-water ratio is generally 1:1.4-1.6.

4. Bagging, sterilization, and mycelial culture

For cultivation bags, low-pressure polyethylene or polypropylene tube material 17 cm wide and 0.4 mm thick can be selected, cut into 33 cm long bags, with one end tied tightly with a rubber band (cut from a bicycle inner tube), and one of the above formulas mixed evenly and loaded into the bag. Where conditions permit, a bagging machine can also be used. During bagging, strive to achieve uniform tightness, and after filling, tie the other end. After filling the appropriate number of bags, place them in an atmospheric pressure sterilization pot for sterilization. The sterilization time is 10-12 h. It is best to fire during the day and let them sit overnight before removing from the pot. After removing from the pot, when the bag temperature drops to about 30°C, inoculation can be carried out.

After inoculation, the bags can be placed in a culture room for mycelial culture. During the mycelial culture process, when the temperature exceeds 28°C and the humidity exceeds 65%, ventilation should be provided to dissipate heat and lower the temperature. During mycelial growth, attention should be paid to shading and aeration. After about 40 d, the mycelium can fill the bags.

5. Strengthen management and harvest at the right time

Bags full of mycelium can be transferred into the cultivation room. The bags can be stacked; the stacking height should be 8-10 layers so they do not fall over. After fruiting bodies appear at the bag opening, remove the rubber band to let them fruit. During this period, suitable temperature, humidity, light, and controlled ventilation must be maintained. The indoor temperature should be kept at 26°C-28°C, the relative air humidity at 85%-95%, and scattered light is suitable for illumination. Lingzhi is very sensitive to carbon dioxide, and poor ventilation can produce deformities. When the edge of the cap no longer grows and brownish-red spores are produced, it can be harvested. When harvesting, it is best to cut with a knife, so that new fruiting bodies can quickly grow again on the original basis. After the second flush matures, harvest again and let it grow again, and grow again and harvest again. After harvesting two flushes, the bags can also be removed and buried in soil to compensate for insufficient water in the bags. As long as the temperature is suitable, three harvests can be obtained. Under normal circumstances, 100 kg of dry material can yield 8-10 kg of lingzhi over three harvests. The harvested lingzhi should be dried promptly.