How to use spent Armillaria-infected wood in Polyporus umbellatus cultivation

Polyporus umbellatus is also known as Di Ling, Polyporus umbellatus Maitake (Japan), wild boar food, pig dung Ling, etc. It is one of the commonly used traditional Chinese medicinal materials, mainly obtained by digging up wild specimens for medicinal use. As natural resources gradually decrease, the contradiction between supply and demand is becoming increasingly acute. In particular, modern medicine has proved that the Polyporus umbellatus polysaccharides B—(1-4) and B—(1-6) contained in the sclerotium of Polyporus umbellatus are a nonspecific cellular immunostimulant, which can significantly strengthen the function of phagocytes in the reticuloendothelial system, inhibit the growth of tumor cells, and reach an inhibition rate of up to 99.5% against tumors in mice, making it one of the medicinal fungi with relatively good anticancer effects and attracting widespread attention from medical and pharmaceutical departments at home and abroad. To solve the severe shortage of medicinal sources and the situation of supply falling short of demand, in addition to paying attention to protecting existing resources, vigorously carrying out resource surveys, and expanding the harvesting area, research work on artificial cultivation and mycelial fermentation of Polyporus umbellatus is also very important.

(1) Preparation of spawn

① Spore propagation: Between July and August, air-dry Polyporus umbellatus flowers (fruiting bodies) and rub them into powder to make spawn. The harvested Polyporus umbellatus flowers must never be exposed to sunlight, and must be protected from rain, mildew, and smoke. It is best to plant them immediately after collection, placing 3 grams of spawn powder in each hole, then covering with humus soil.

② Vegetative propagation: Select fresh Ling with an uneven surface and many nodules as seed Ling; this kind of Ling has vigorous growth power and produces many buds quickly. To save materials, bud eyes can also be used for seed cultivation and propagation. The green or white budding sites of the sclerotium are where Armillaria has invaded, and fluorescence can be seen at night. To prevent the seed buds from drying out, they should be wrapped in wet cloth. After the ground is prepared, place a soil ball containing seed buds into each hole and bury it deeply with humus soil, then firm it.

(2) Cultivation methods

① Cultivation: Choose slightly acidic, moist sandy soil with good aeration and permeability, with a slope facing southwest or northwest, pits 50 cm deep, and 70 cm long and wide. Plant 5 fungal logs per pit, with logs about 60 cm long and about 10 cm in diameter. They should be cultivated in advance and have Armillaria rhizomorphs. During cultivation, place the broken small pieces of Polyporus umbellatus sclerotium one by one on the parts of the fungal logs where there are more rhizomorphs, and press lightly so that the cut surface of the Ling pieces closely combines with the Armillaria rhizomorphs and fungal wood, so that Polyporus umbellatus and Armillaria can establish a nutritional relationship. Place 5-8 Ling seeds on each fungal log. The bottom of the pit should be loose; arrange the fungal logs evenly, with a distance of 6-10 cm between logs. After the Ling seeds are placed, fill with humus soil, press lightly, leave no gaps, and keep the firmness moderate. Cover with 10-15 cm of soil, then cover the surface with some dead branches and fallen leaves, slightly higher than the ground.

② Cultivation time: Generally in spring and summer from late April to early June; in autumn from late August to late October.

③ Cultivating fungal wood and fungal beds: There are many tree species used for cultivating Polyporus umbellatus, and any that can grow Armillaria can be used. Commonly used ones include ring-cupped oak, cork oak, small oak acorns, white birch, Korean pine, etc. Branches about 10 cm in diameter are sawed into short sections 60 cm long and dried for 10-15 days so that 20%-30% of the moisture is lost. Cut fish-scale notches every 3-5 cm; cut four rows on thick logs and three rows on thin logs. Use pit cultivation, using rotten tree roots and branches with Armillaria, old fungal logs and fungal branches used for growing Gastrodia elata as spawn. The pit is 50 cm deep and 70 cm long and wide. In the lower layer place 3 new logs and 2 old logs; in the upper layer place 5 new logs, then cover with 10-15 cm of soil. One fungal bed can cultivate two pits of Polyporus umbellatus. During cultivation, dig open the fungal bed, take out the upper 5 fungal woods and plant one pit nearby, and plant one pit in place with the lower 5 fungal woods.

④ Post-planting management: Polyporus umbellatus cultivation does not require fertilizing or hoeing weeds; keep it in a wild state. After planting, cover with some dead branches and fallen leaves and keep the soil moist regularly. Prevent trampling by people and livestock and damage by rats. Do not frequently dig and inspect, so as not to damage the nutritional relationship among it, Armillaria, and the fungal wood.

⑤ Harvesting time: It can be done in spring in April and May, and in autumn in September and October, planting while digging. For digging wild ones, it is best at the end of summer and beginning of autumn when the fruiting bodies are open. Polyporus umbellatus is a perennial fungus; the sclerotium remains unrotted for many years, and it can also be harvested after 2 years. If its growth conditions are met, with good fungal wood, a temperature maintained at 18-20°C, a soil moisture content of about 10%, and slightly acidic conditions, a relatively high yield can be obtained in 2 years, increasing 19.8 times.

⑥ Harvesting and processing: After digging up, remove all sediment and Armillaria rhizomorphs from the sclerotium, and air-dry, sun-dry, or oven-dry it. 1.8-2 kg of fresh Polyporus umbellatus yields 1 kg of commercial product.