Keywords: Yushu edible fungi

Brief introduction of varieties

I. Overview

Elm, also known as white elm, is naturally distributed in three northeastern provinces of China. Yu 'er is delicious and effective, and enjoys the reputation of "king of forest food". Locals eat its wild fruiting body and use it to treat bacillary dysentery. In recent years, the analysis shows that the fruiting body of elm contains the effective component of furazolidone. The strain 1988 was successfully domesticated by the Institute of Soil and Fertilizer of China Academy of Agricultural Sciences, and a series of cultivation techniques were formed.

Second, biological characteristics.

1. form

The fruiting body is gelatinous, soft, medium-sized, sessile and flaky, light yellow, yellow, light orange to pink, with a dirty white to khaki fluff layer on the back, and the mushroom meat is light orange, crystal clear and translucent. Most of the lugs are 3 ~ 15cm, and the thickness is 1 ~ 3cm. After drying, it shrinks strongly and hardens, and the color becomes dark brown.

2. Environmental conditions for growth and development

1 nutrition. Although elm naturally grows on the dead and semi-dead trunks, stumps and stumps of elm and elm, it is not a parasitic fungus, but a saprophytic fungus with weak parasitic effect. Although it occurs naturally on dead trees, there is no enzyme system to decompose lignin. But mainly decomposes cellulose and hemicellulose. Therefore, in practical cultivation, although sawdust can be used as the main raw material, its yield is not as high as that of cellulose-rich raw materials such as cottonseed hull and waste cotton. Therefore, cottonseed hulls and waste cotton are often used as the main raw materials for cultivation.

② temperature. The optimum temperature for mycelium growth is about 25℃, and 35℃ is its lethal temperature. The fruiting body primordium was formed at 5 ~ 26℃, and the optimum temperature for fruiting body differentiation was 10 ~ 22℃. The primordia below 10℃ and above 26℃ could not differentiate.

③ Humidity. The suitable substrate water content for mycelium growth is 60% ~ 65%. When the water content of the material is lower than 55%, mycelium can grow, but the primordium of fruiting body is not easy to differentiate in the future. The formation and development of fruiting bodies need 85% ~ 90% atmospheric relative humidity.

④ Lighting and ventilation. Mycelia grows faster and stronger in the dark than in the light, and visible light has a strong inhibitory effect on mycelium growth. Light can promote the formation and development of fruiting bodies. Auricularia auricula is extremely sensitive to light, and the weak light of 20 ~ 60 lux every few minutes is enough to induce the formation of fruiting body primordium. Sufficient light can also make the earlobe thicker and darker. Ventilation is more important at the heading stage than at the fruiting stage, especially in the middle and late stage of fruiting body development. When there is insufficient ventilation, the roots of the ears are prone to mildew.

⑤ pH value (pH value). PH 5.5 and 7.0 have no significant effect on the mycelium growth of Pleurotus eryngii, and pH 5.5 ~ 6.0 is the most suitable.

Three. Key points of cultivation techniques

1. Planting season and place

In the north, it is easy to plant in spring and autumn. The heading period of spring sowing is from the end of March to the beginning of June, and the heading period of autumn sowing is from 10 to 12. According to this, the sowing date is calculated forward, and the bag planting date is extended by 40-50 days. Ulmus pumila can be cultivated in idle houses, small arch sheds, various types of arch sheds, various types of greenhouses and sunny beds. This place needs enough light.

2. Common formulas and cultivation techniques

Commonly used formulas are:

Formula 1: 99% cottonseed hull or waste cotton, gypsum, 0.2% calcium superphosphate,

Formula II contains 85% corncob powder, 14% wheat bran, 1.3% gypsum, 0.5% lime and 0.2% calcium superphosphate.

Formula 3: sawdust 78%, wheat bran 20%, 1% sugar, 1% gypsum.

Elm is planted in clinker bags and cannot be cultivated with raw materials and fermented materials. The technological process is as follows: batching (polypropylene bag with width 15cm and length of 40cm) → 0. 14mpa sterilization 1.5h or 0. 12mpa sterilization for 2h → cold inoculation → culture at 22 ~ 26℃ until mycelium is full → light stimulation for 7 ~/kloc. About 10 day → reduce the humidity to promote the ear differentiation (reduce the humidity to 85% ~ 90% of the relative humidity of the atmosphere) and keep the temperature suitable for the growth of fruiting bodies and good ventilation, and harvest after 10 ~ 15 days. You can usually harvest three crops. The seedling stage of the whole ear is 60 ~ 70 days, the whole production cycle is about 120 days, and the yield is 100% ~ 250%, which mainly depends on the kinds of culture materials used. The output of waste cotton is the highest, followed by cottonseed hull, corncob powder and sawdust.

3. Key cultivation techniques

The key to successful cultivation and ideal yield and quality of elm lies in:

① Strict sterilization. The sterilization time of elm culture material is longer than that of most edible fungi. For most edible fungi, 0. 14 MPa sterilization takes 1 hour, 0. 12 MPa sterilization takes 1.5 hours, while elm takes 2 hours. Disinfection is the key to its successful cultivation.

② Main cultivation materials. Using waste cotton and cottonseed hull as main raw materials, higher yield can be obtained than other raw materials. The relative biological efficiency of waste cotton as the main material can reach 200% ~ 250%, the relative biological efficiency of cottonseed hull as the main material can reach 120% ~ 200%, while sawdust and corncob are only 60% ~ 90%, which is the key to high yield.

③ Management of harvesting and regeneration spike. The management technology of ear picking and regeneration is an important link to obtain high yield. The correct way to harvest is to cut off the mature ear pieces with a disinfection blade, leaving the ear base. If the ear base is pulled up and harvested, the next ear will not be born, and one crop only accounts for about 60% of the total output. After harvesting, the wound at the cutting mouth should be dried, protected, supplemented and sprayed, that is, the water should be stopped after harvesting and the surface of the ear base should be ventilated and dried. After 2-3 days, the bag mouth should be loosened to keep moisture, which is beneficial to the germination of regenerated ears. After the next ear germinates, water should be injected into the bag to replenish water. After water injection, open the bag mouth and spray water into the air to improve the relative humidity of the atmosphere. The second crop ear accounts for about 30% of the total output, and the third crop ear accounts for 10% ~ 20% of the total output. Improper management of regenerated ears can easily lead to mold infiltration at the base of ears and reduce the yield.

After the elm is harvested, it should be dried in time until it is dry. The dried elms have hard ears and click each other. It should be noted that elm is not suitable for fresh food but for drying, and the porphyrin contained in it will cause some allergic reactions. Common allergic reactions to fresh food are gastrointestinal discomfort and indigestion. However, it is very safe to eat dried elm after soaking.