Cultivation technology of black fungus

Today I will introduce to you the cultivation technology of ground-grown black fungus:

1. Bacteria selection

There are many high-quality and high-yield varieties of ground-grown black fungus in China, mainly including Hei 29, Yanming No. 1, Hei 916, Yannong No. 11, Changbaishan No. 7, etc. The average yield of dry fungus per bag can reach 50 grams. Black fungus varieties can be divided into chrysanthemum type and multi-piece type according to their shape. Ground-grown black fungus generally chooses multi-piece type. According to the different accumulated temperatures required for the post-ripening process, it can be divided into early, medium and late maturing varieties. Early-maturing varieties generally cut when the mycelium is about to fill the bag or just fill the bag, and the ears can be produced. At this time, the yield is also the highest. If the cut is not timely, the yield will be affected; late-maturing varieties still need a post-ripening process after the mycelium fills the bag, and the accumulated temperature required is above 500℃ (average daily temperature × number of days). If the cut is made before the accumulated temperature required for the post-ripening process is reached, the cut mouth will not grow fungus, and it is easy to be contaminated and grow miscellaneous bacteria; the varieties between early and late maturing are called medium-maturing varieties.

At present, spring fungus is generally planted in Yanbian area, because the ear pieces of spring fungus are thick, the color is dark black, and the quality is good. However, spring fungus is produced in winter, so there are certain requirements for the culture room; first, good heat preservation, and second, warming conditions. The economic benefits of ground-grown black fungus depend on technology first, but more importantly, on scale. If there is a culture room that can cultivate 10,000 bags of fungus at a time, 10,000 bags will be made. The small number of production will increase the production cost relatively. If late, medium and early varieties are selected, 30,000 bags can be produced. That is, 10,000 bags of late varieties will be produced before mid-December, and 10,000 bags of medium varieties will be produced before early February. The late and medium-mature bags full of mycelium can be put in woven bags and piled indoors for storage. The best temperature is 0°-10℃. If there is no place to put them, they can be placed outdoors and covered. Finally, 10,000 bags of early varieties will be produced. Although the production time of these three varieties is different, they can all be cut in April and can produce ears at the same time, which has three times the economic benefits of 10,000 bags.

2. Preparation of culture medium

All broad-leaved tree chips can be used as culture medium. When mixing ingredients, attention should be paid to the appropriate ratio of raw materials, material-water ratio and pH value. These factors affect the physical and chemical properties of the culture medium and are directly related to the growth and development of wood ear mycelium. Formula 1: 78% sawdust, 18.5% rice bran, 2% soybean powder, 1% gypsum powder, and 0.5% quicklime. Formula 2: 86.5% sawdust, 10% wheat bran, 2% bean cake powder, 0.5% quicklime, and 1% gypsum powder. Formula 3: 78% sawdust, 20% wheat bran, 1% gypsum, and 1% white sugar. The water content of each formula is about 60%. Generally, when the culture medium is kneaded and mixed by hand, there are water marks between the fingers, and it is better not to drip more than one drop of water.

3. Mixing and bagging

It is best to use a mixer to mix the culture medium. If you mix it manually, at least ensure the "three threes" system, that is, mix the auxiliary materials three times first, mix the main materials and auxiliary materials three times, and mix them three times after adding water. Alternatively, mix the auxiliary materials first, then add a layer of main materials and a layer of auxiliary materials, and then mix them in the forward and reverse directions 2-3 times each. After adding water to the culture medium, mix it well and pile it for 2 hours to allow it to be soaked with water. Do not mix it with dry materials to avoid affecting the sterilization effect.

Bagging can be done with a bagging machine, which can complete the loading and punching at one time, saving manpower and ensuring the quality of bagging. The bags must be 17×33cm polyethylene bags, because polyethylene bags are not easy to break at low temperatures, are soft and easy to shrink, the bag wall is close to the mushroom sticks, and has good moisture retention when opening the ears. It is not easy to cause water accumulation in the mushroom bag when spraying water, which reduces the late pollution during the ear period. The filling should be moderately tight. Loose materials will cause weak mycelium and easy aging, and easy contamination when ears come out. Too tight materials will cause poor ventilation and slow fungus growth. Generally, each bag contains 1.1-1.2 kg of filling. After filling, put on the collar and press the lid. The lid and the material surface should maintain a space height of 3-5 cm.

4. Sterilization and inoculation

The filled cultivation bags should be placed in a 55×44×30 cm iron basket and then moved into the pot. The sterilization method is mostly normal pressure sterilization. Normal pressure sterilization time should be calculated from the time the temperature in the pot reaches 100°C, and last for more than 6 hours, and then simmer the pot for 2 hours. If the temperature drops below 100°C during sterilization, the sterilization time should be extended by at least 2 hours to achieve thorough sterilization.

Inoculation should be strictly sterile, and the inoculation technique should be mastered. The inoculation box (room) should be disinfected with formaldehyde 2 days before inoculation. The surface of the strain bottle should be washed with 2% potassium permanganate solution, and the inoculation tools should also be disinfected before being placed in the inoculation box (room) with the strain. For suspected strains, you can first remove the cotton plug and smell it. If it has a fresh fragrance, it is a qualified strain. If it has a wine, sour, or smelly smell, it is a bad strain and should be eliminated. When inoculating, dig out the old bacteria blocks at the mouth of the bottle, and do not break the strains too much. If the strains are too broken, they will germinate slowly and are easily infected by mold. Generally, one bottle of secondary bacteria can be inoculated with 40-50 bags of tertiary bacteria (cultivation bags).

5. Cultivation

Choose a dry, sanitary, well-ventilated, light-proof and heat-insulating room as the culture room. Install the culture rack in the culture room, and the height is determined by the height of the room. Generally, it is more appropriate to build 8 layers in a room with a height of 3.1 meters, and 9 layers in a room with a height of 3.4 meters. Generally, it is more than 0.45 meters above the ground, and a layer is built every 30 centimeters, and the top layer is 0.5 meters from the ceiling. When the temperature is low, the lowest layer is slightly higher than the ground, and enough ventilation space is left on it to facilitate ventilation. The width of the culture rack is based on the principle of convenience for the bag to be put on and off the rack. Generally, 0.8 meters is more suitable for single-sided racks (against the wall), and 1.5-1.6 meters is more suitable for double-sided racks. There should be a certain interval between the wooden boards of the bed to facilitate ventilation. The wooden boards are required to be dry and free of burrs to prevent puncturing plastic bags. The culture racks should be tightly connected to prevent losses caused by falling racks.

Before placing the bags, the room is disinfected with formaldehyde. When placing the bags, turn the bags upside down first to make the bacteria in the holes fall down, and then place the bags upright to ensure that most of the bacteria cover the surface of the material, and a small part of the bacteria falls into the holes. After inoculation, the temperature of the culture room should be 25-28℃ for the first 7 days, which is conducive to the resurrection and colonization of the bacteria and reduces the contamination rate; after 7 days, the material temperature is generally higher than the room temperature. To prevent the bacteria from burning, the culture room should be cooled to about 20-25℃ to promote the mycelium to grow faster and eat the material. After the mycelium fills the bag, the temperature of the culture room should be reduced to about 20℃ to continue the culture, so that the mycelium accumulates more nutrients and turns from vegetative growth to reproductive growth. After 10 days of cultivation, ventilation should be started for more than half an hour in the morning and evening, and keeping the room dark is conducive to the growth of mycelium. If miscellaneous bacteria are found during the cultivation period, pick them out and re-bag them for sterilization, which basically does not affect the yield. In addition, the culture room should be humidified and disinfected with Lysol every day. Fumigation with formaldehyde once every 5 days. The relative humidity of the air should be controlled between 45-60%, and the room should be kept "ventilated and dry, preferably dry but not wet". The pile should be turned over or the racks should be turned over once a week to avoid burning the fungi.

6. Centralized ear bud management

The ear field should be built near water sources, with good water quality, clean and sanitary, no pollution sources, good ventilation and fresh air. For old ear fields, the discarded fungus bags and residues should be removed first, and then the fields should be raked, leveled, and made into beds. The beds should be watered thoroughly to keep them moist, and 5% lime water and 800-1000 times DDV should be sprayed for disinfection, sterilization and insecticide. A layer of plastic film or plastic woven bag pieces, sunshade nets, fine yarn nets, etc. should be laid on the bed surface to prevent rainwater from splashing mud and sand on the ear pieces, reducing the value of the goods.

The best time to cut ears in spring is around early May, and the cutting should be completed before early July. The best time to cut ears in autumn is from early to late July, and the cutting should be completed in early October. If the ears are not cut out completely, they can be cut again in the spring of next year.

Different ear beds should be made for different terrains. For plots with poor drainage, ear beds should be made 5-30cm above the ground; for plots with good drainage, ear beds should be made 5-25cm lower than the ground. The ear bed should be 150-200cm wide, with no limit on length, but it will be difficult to manage if it is too long. After the ear bed is made, it should be watered heavily so that the bed surface can absorb enough water, and then 100 grams of quicklime per square meter should be sprinkled for disinfection.

Remove the cover of the bag, tighten the bag mouth by hand, and make a V-shaped mouth. The angle of the mouth is 50-60°, the oblique length of the angle is 1.8-2cm, and the depth is 0.5-0.8cm. Each bag should have 4-5 layers, and the lowest layer should be more than 5cm above the ground. Each layer should have 4 mouths; chrysanthemum varieties can also be scored in stripes, with 5 strips along the bag and 2 strips at the top. In addition, some people in Heilongjiang Province use the method of nail piercing to score, which is also effective. The ear pieces are all single pieces and of good quality. Place the spray belt with the small hole facing down in the middle of the bed, and place the bags upside down on both sides, with a spacing of 10-12cm between the bags, and then cover them with straw curtains. It is also possible to centrally germinate, with a spacing of 1cm between the bags, and place them upright, and then place the bags upside down in the beds.

④ Management of ear buds The ear bud period generally takes 10-15 days. During this period, the relative humidity of the bed surface should be maintained at 85%-90%. If the humidity is not enough, connect the water spray belt to the water source for a few minutes to reach the required humidity. If the bed surface temperature is higher than 27°C during the day, use ventilation to keep the bed surface temperature between 22-24°C. Appropriate scattered light can induce ear base formation. The straw curtain should be opened for half an hour in the morning and evening, and ventilation requirements can be met at the same time.

7. Management during the fruiting body growth period

Adjust the humidity After the ear buds emerge, the straw curtain can be removed, and water can be sprayed every morning and evening, preferably with micro-spraying. In the early stage, due to the poor resistance of the ear buds, frequent spraying, clear spraying, and fine spraying should be used to keep the relative humidity of the air at 85%-90% to keep the ear pieces moist and not curled. When the ear buds grow to a flat or disc shape, the amount of water sprayed should be appropriately increased to make the relative humidity of the air reach 90%-95% to prevent the ear pieces from transpiration and water loss and promote rapid growth. Attention should be paid to alternating dry and wet management, especially when the ear stems and ear pieces grow slowly, water should be stopped for 3-5 days to allow the mycelium to recuperate and accumulate nutrients, and then water should be sprayed to make the ear pieces grow robustly. Before the ear pieces mature, it is advisable to reduce the amount of water sprayed to keep the relative humidity of the air at 75%-85%; under such humidity conditions, the ear pieces can not only control the ejection of spores, but also be clean and water-free, not easy to rot, and have thick and elastic flesh, and good product quality.

Control the temperature. The temperature during the ear opening period should be 20-22℃, which is conducive to the growth of the ear pieces in an orderly, strong, good ear shape, deep color, and high commodity value. If the temperature is higher than 25℃, it is difficult to open the ear pieces. In hot weather, the fruiting body will breathe vigorously, cell division will accelerate, dry matter accumulation will be small, the ear pieces will be thin, and the yield will be low. Therefore, in hot weather, you can cover the straw curtain and spray water to cool down to ensure the good growth of the ear pieces. There is no need to spray water when the temperature is below 15℃ or it rains.

Adjusting the light The growth of the fruiting body requires certain light conditions. Under sufficient light conditions, the ear pieces are thick, dark, tender and strong; otherwise, they grow slowly, are light in color, have soft bones and low commodity value. Therefore, the covering should be removed regularly to ensure sufficient light.

Fresh air is conducive to the good growth of the ear pieces. If the ventilation is poor or the bags are placed too densely, the ear pieces will not be easy to open, and they will easily form deformed ears such as "chicken claw ears" or "round ears", which will lose their commercial value, and they will be easily infected by bacteria and rotten ears, reducing the yield. All obstacles inside and outside the ear field should be removed, and the covering should be removed regularly to ventilate and exchange air so that the ear pieces can grow well.

8. Harvesting and processing

The weakening of the elasticity of the ear pieces is a sign of maturity. When the ear pieces are mature, their physiological activity decreases. If they encounter high temperature and high humidity, they are very likely to be infected by bacteria and cause rotten "runny ears". Therefore, they should be harvested in time, especially in high temperature and high humidity seasons. The ear pieces that are 80% to 90% mature should also be harvested. When harvesting, the ear roots left on the fungus bag must be cleaned up to avoid infection with bacteria and "runny ears". For the picked fungus, remove the excess ear roots and put them on the sand net to dry in time. There is no need to turn them over many times before they are completely dry to avoid the appearance of "fist ears".

9. Disease and Pest Control of Black Fungus

(1) Fungal contamination and prevention of black fungus Fungal contamination is the most common phenomenon in ground-grown black fungus, which has caused certain economic losses to growers. The causes of contamination are:

First, the sterilization is not thorough. This is caused by the use of normal pressure sterilization, or abnormal bagging, stacking, and temperature rise. Prevention and control measures: Mushroom farmers should be proficient in sterilization technology to eliminate infections caused by human factors.

Second, the strain is bad. The strain is of poor quality, the cultured mycelium is weak, thin, and has poor resistance to stress, which increases the chance of infection by foreign bacteria. After the bag is opened, foreign bacteria quickly grow on the surface of the material, resulting in a significant drop in yield. Preventive measures: Choose pure strains with white, strong, and vigorous mycelium (when the culture medium is full of mycelium and exposed to light, plum-shaped colloid primordium will form).

Third, opening the bag too early. When the mycelium fills the bag, it should be cultured for another week. Do not rush to open the bag to take out the ears. Otherwise, because the ear base has not formed due to the long opening time, the miscellaneous bacteria will take the opportunity to invade, and cotton wool will appear at the opening. After 1-3 days, it will become mold spots and quickly spread to the whole bag, causing a reduction in production. This stage is mainly infected by Trichoderma and Penicillium. Preventive measures: After the mycelium fills the bag, continue to culture in a light environment for 10-15 days. After the colloid ear base is induced, the bag can be opened to take out the ears.

Fourth, high temperature, high humidity and improper water management. High temperature and high humidity are the main factors of pollution. Under high temperature, the growth of black fungus mycelium is hindered, the mycelium turns yellow, spits yellow water, dissolves automatically, and causes the fruiting body to rot or ear flow. Therefore, you should try to avoid opening the bag to take out the ear in the high temperature season. If you encounter short-term high temperature, you should strengthen ventilation. In management, you should master the "dry-dry-wet-wet" water management method to prevent the occurrence of ear flow. In addition, improper management is also a major factor leading to mold. Some growers continue to sprinkle water on the bag to increase humidity. As a result, the mouth of the ear bud often accumulates water, causing mold to grow. The ear buds that have grown are in a saturated state for a long time, causing the ear pieces to rot. Preventive measures: After opening the bag and placing it until the ear buds grow up, moisturizing is the main method. Only spray water on the ground, and do not pour water on the bag. When the ear buds seal the opening, you can spray less and more frequently to keep the ear pieces moist. After the ear pieces are opened, you can spray water on the ear pieces to keep them moist. If mold has appeared at the opening, use a knife to dig out the mold and then cover it with lime powder to control the spread of the mold.

(2) Prevention of fungus oozing When cultivating black fungus, preventing fungus oozing is one of the key measures to increase production and income. Especially in summer, the fungus oozing phenomenon is particularly prominent due to high temperature and high humidity. If it is not prevented and controlled in time, it will cause a large-scale reduction in production and a decline in the quality of black fungus. The preventive measures are: First, timely harvesting. Untimely harvesting is one of the causes of fungus oozing. After the fungus pieces mature, their physiological activity decreases. If they are exposed to high temperature and high humidity, they are very likely to be infected by bacteria and cause rotten fungus oozing. Second, remove the fungus roots. The fungus roots left on the bags during harvesting must be cleaned up. The fungus roots left after harvesting will not germinate and grow. Instead, they will be infected by bacteria and cause fungus oozing when exposed to high temperature and high humidity. Therefore, do not leave fungus roots on the bags. Third, spray water reasonably. When the temperature is high, spray water in the morning and evening, not at noon when the temperature is high. In addition, the air humidity of the fungus production site should be maintained. Spray less on the bags to prevent too much water from accumulating on the fungus pieces, which will cause fungus oozing. Fourth, control the temperature and humidity. High temperature, high humidity and poor ventilation will breed bacteria and multiply rapidly, which is also the main cause of runny ear. Therefore, the temperature should be controlled below 25℃ and the humidity should be controlled at around 85%.

(3) Pest control of black fungus In the cultivation of black fungus, gall midges, flea flies, fruit flies, moths, mites, springtails, nematodes, etc. mainly harm the mycelium and fruiting bodies. For example, the larvae of the yellow-legged fungus midge eat the ear pieces, causing the ear pieces to rot, and sometimes also eat the mycelium. The control of various pests is mainly prevention-oriented. When there are pests in the cultivation site, it is advisable to use high-efficiency, low-toxic, and non-residue insecticides for control. Pyrethroids, trichlorfon, etc. can be used, and the dosage should be strictly controlled. It is also possible to use the characteristics of some pests that they are phototactic and decay-tactic to lure and kill them, which can achieve better results.