A Brief Introduction to Nameko
Nameko (Pholiota nameko) is also called Huagu, Guanmaosan and Huazimo in China. It produces cluster mushroom with small cap and large quantity. The cap is puce with early shape of hemisphere, when grows up its center sink and look flat. The cap has a smooth surface with mucilage and without squama, and a diameter of 5 cm-8.6 cm. The gill grow vertically and densely, white or yellow in early time, and turn to rust or ochre color when mature, at the same time the context change from weak yellow to brown. Its stipe is column with length of 5 cm-7 cm. Its yellow annulus occurs at the upside of the stipe.
I. Preparation of the substrate
Nameko can be cultivated with bed-log or substitute. The general broadleaf bed-logs all can be used in the cultivation of this mushroom, among them the beech; chestnut and maple are suitable for bed-log preparation in the artificial cultivation. The substitute produce consistent and clean mushroom, the special fragrance is not so dense as that of bed-log cultivation, the mucilage is also less, but taste daintily, and the production period is shorter, and cost is lower and the benefit is higher.
(I) Formula of substrate in substitute cultivation
1. Sawdust medium:
sawdust 90%, wheat bran (or rice bran) 8%, corn powder 2%, ratio of materials and water 1:1.4.
2. Cottonseed nut medium:
cottonseed nut 78%, wheat bran 20%, sugar 1%, gypsum 1%, ratio of materials and water 1:1.4.
(II) Treatment of substrate in substitute cultivation
1. Bottle cultivation:
The evase spawn bottle or can bottle is preferred. Fill the prepared substrate to where 1cm apart from the bottle mouth and planish it, remain an inoculation hole at the center, cover the bottle mouth with plastic film or kraft, and tighten with an elastic band. Autoclave the bottles, be careful when raising and dropping the pressure to avoid the covering broken.
2. Plastic bag cultivation:
Fill the prepared substrate into the bag, tighten with an elastic band, and put the bags flat wise in the autoclave for sterilization (4 hr=6 hr).
II Cultivation management
(I) Inoculation and spawn running
After sterilization, the substrate bags (bottles) are cooled to under 30°C, and remove into the inoculation hood. The seed volume is about 3%-5% of the dry weight of substrate. If the bottle is used, open the bottle in the inoculation hood directly, and recover it after inoculation. When using the bags, open the bag and make holes on the substrate surface with a wood stick, 4-6 holes for 1 Kg substrate and 8-10 holes for 2-3 Kg substrate. Then transfer the spawn into the holes, 2 pieces of spawn of horse bean size for one hole, and scatter a layer of spawn on the substrate surface. Put the plastic ring on the bag, turn the inside bag out of the ring, and fill sterile cotton plug. After inoculation the bags (bottles) are moved into the incubation room for spawn running.
2. Spawn running:
This mushroom needs a long time for spawn running. If inoculated in late winter or early spring, the spawn will finish running in August, lasting about 6 months. If inoculation in September, it needs 70-80 days for spawn running. The main work in spawn running is the management of temperature and moisture. The mycelia grow well under 4-32°C, the optimum temperature is 25-26°C. It stops growing at 32°C and dies under over 40°C in a long period. The mycelia have a better tolerance to low temperature, but growing at below -5°C in a long period will affect the reproduction of the mycelia. Keep the room temperature of about 25°C during spawn running, in order to promote the rapid development of mycelia, inhibit the contamination of weed mould, and bring forwards the fruiting date. Leave it grows slowly if there is no condition for raising temperature. The incubation room should be kept clean, without over wet to avoid weed mould occurs. The substrate moisture can not be under 70%-75%. If there is too much temperature difference in the room, the mycelia bags should be removed once every 15 days, and check the situation of spawn running. Under the suitable temperature, the spawn pieces will grow into the substrate about 10 days later; about one month later, white mycelia will cover the substrate surface; 2 months later, the substrate will be full of mycelia and form a whole mycelia clump. But it still cannot produce fruit body and need further culture. Here the ventilation should be controlled to avoid too high temperature. The mycelia continue growing, absorbing and accumulating nutrition. Finally, the coat of rust color forms on the surface of mycelia clump, and the spawn running finish.
(II) Fruiting management
1. Breaking bag and cutting coat:
Get rid of the plastic bag when the mycelia mature, open the bottle mouth if using bottle. When the coat is too thick to be helpful for fruit body coming out, cut the coat with a bamboo knife or an iron nail vertically and horizontally in breath of 2 cm and deep of 1 cm. Cutting too deeply will result in the mycelia clump fracturing easily. Put the mycelia clump on the bed flatly or upright, sprinkle water and adjust the room temperature of about 15°C to promote the fruit body forming.
2. Temperature management:
The fruit body can grow under 5°C-20°C. The temperature of above 20°C will result in smaller fruit body with thin stipe and small cap, early opening, even no fruit body. Under low temperature of 5°C-10°C the fruit body still grow strongly but in lower quantity. The optimum temperature for fruit body occurring is different based on the strains, in general 10°C-18°C. In late autumn after October, there is a big nature temperature difference, which should be utilized sufficiently, at the same time enhance the management to improve the production. The air temperature is lower at night, and the room temperature should be kept no less than 10?; the air temperature is higher at noon, and the ventilation should be noticed to kept the room temperature no higher than 20°C.
3. Humidity management:
The moisture is one of the important factors for high production of Nameko. Shortage of moisture will affect seriously the production and inhibit the fruit body differentiation, resulting in the shrunk fruit body, no mucilage exudation, growth stop even death. To ensure the need of moisture for mushroom development, sprinkle water properly to raise the mycelia clump moisture (70%) and air humidity (90%). Sprinkle water at least twice every day, and the water temperature can’t be quite different with the air temperature. Sprinkle water slightly and frequently, avoid the water accumulate on the mycelia surface and cause rot.
4. Ventilation management:
In fruiting phase the mycelia enhance the respiration, and the oxygen requirement increase obviously, so it is necessary to keep the indoor air fresh. When ventilating, the change of temperature and humidity should be noticed. If it is too hot and too wet indoor, ventilation should be reinforced. Incorrect ventilation is one of the reasons of deformed mushroom.
The key point for the lasting time of fruiting phase and the production lies on the management level. With proper management, 3-4 flushes mushroom can be harvested and the biological efficiency can reach 60%-70%. The harvesting time is different based on the purpose. Non-opening mushroom is tender with good quality and flat cap. When the spores scatter, the mushroom is old and matured with lighter fruit body and worse quality. When harvesting, pick up the stipe with fingers and pull out slightly, and store at a cool place. Generally the mushroom can be stored at the cool place for 4 days, or more than one week at about 5°C.