A Detailed Guide to Black Fungus Planting Methods and Cultivation Techniques
I. Overview Black fungus is also called wood ear, smooth wood ear, or cloud ear. Taxonomically it belongs to the class Basidiomycetes, order Tremellales, family Auriculariaceae, genus Auricularia. There are about a dozen or more species in this genus, such as black fungus, hairy wood ear, wrinkled wood ear, felt-cap wood ear, horny wood ear, shield-shaped wood ear, and so on. Among these wood ears, only the smooth wood ear has a plump, tender texture and a delicious flavor...
I. Overview
Black fungus is also called wood ear, smooth wood ear, or cloud ear. Taxonomically it belongs to the class Basidiomycetes, order Tremellales, family Auriculariaceae, genus Auricularia. There are about a dozen or more species in this genus, such as black fungus, hairy wood ear, wrinkled wood ear, felt-cap wood ear, horny wood ear, shield-shaped wood ear, and so on. Among these wood ears, only the smooth wood ear has a plump, tender texture and a delicious flavor, and is known as a mountain delicacy.
Black fungus has a long history in our country and was recognized and used by the working people early on. It was recorded as far back as more than 2,100 years ago in the Rites of Zhou. In the Essential Techniques for the Welfare of the People by Jia Sixie of the later Wei dynasty, the method of processing wood ear into pickled wood ear is recorded. In the Tang Materia Medica Annotated by Su Gong and others of the Tang dynasty, the tree species and methods used to produce wood ear at that time are also recorded. Li Shizhen, a physician of the Ming dynasty, recorded in the Compendium of Materia Medica: "Wood ear grows on decayed wood... [Flavor and nature] sweet and neutral... [Indications] benefits qi and prevents hunger, lightens the body and strengthens the will... Duan Hu treats hemorrhoids... abnormal uterine bleeding, and bloody dysentery with blood in the stool." This shows that in ancient China, besides listing wood ear as a delicacy, there was also considerable research on the medicinal use of black fungus.
According to modern scientific laboratory analysis, every 100 grams of fresh black fungus contains 11 grams of water, 10.6 grams of protein, 0.2 grams of fat, 65 grams of carbohydrates, 7 grams of cellulose, and 5.8 grams of ash (the ash includes 375 mg of calcium, 201 mg of phosphorus, and 180 mg of iron); in addition, it also contains various vitamins, including 0.031 mg of provitamin A (carotene), 0.7 mg of vitamin B (of which B1 is 0.15 mg and B2 is 0.55 mg), 217 mg of vitamin C, provitamin D (ergosterol), and glycogen, etc. Therefore, black fungus is relatively rich in nutrients and delicious in taste.
Medicinal effects of black fungus: suitable for nourishing and strengthening, clearing the lungs and benefiting qi; enriching the blood and invigorating blood circulation, and for postpartum weakness and numbness and cramps of the hands and feet, etc. At the same time, because black fungus is a gelatinous fungus, its fruiting body contains abundant gelatinous substances, which have a good cleansing and lubricating effect on the human digestive system. It can remove accumulated spoiled food and hard-to-digest fibrous food from the stomach and intestines. At the same time, after the active substances in black fungus are absorbed by the human body, they can clear and moisten the lungs, so it is also one of the health foods for textile workers and mine workers. Recently, according to research findings from the University of Minnesota Medical School in the United States, regularly eating black fungus can reduce ordinary blood clots in the human body and has a role in preventing and treating cardiovascular diseases.
Whether in output or quality, our country's black fungus ranks first in the world. It is a flagship export commodity of our country, sold far away at home and abroad, and enjoys a very high reputation in the countries of Southeast Asia. In recent years, it has entered the European and American markets, with relatively high foreign exchange value.
II. Biological Characteristics of Black Fungus
Black fungus is a gelatinous fungus belonging to the fungal kingdom, and it is composed of two parts: mycelium and fruiting body. The mycelium is colorless and transparent, made up of many tubular hyphae with cross walls and branches. It grows inside decayed wood or other substrates and is the vegetative organ of black fungus. The fruiting body grows laterally on the surface of wood or culture material. It is its reproductive organ and also the part people eat. When the fruiting body is first formed, it looks like a small ring. As it continues to grow and develop, it spreads into a wave-like individual, concave and smooth on the underside, with veining, convex on the back, and with the margin slightly rolled upward. Its overall shape is quite like a human ear, hence the name.
When the mycelium develops to a certain stage, it twists together to form the fruiting body. When fresh, the fruiting body is gelatinous, semi-transparent, dark brown, and elastic. After drying, it shrinks into a horny texture, with the underside smooth and lacquer-black, hard and sparse, and the back dull-colored with short downy hairs. After absorbing water, it can still return to its original state. During the mature stage, the fruiting body produces basidiospores (seeds). The basidiospores are colorless and transparent, sausage-shaped or kidney-shaped, smooth, and are on the underside of the ear piece. After maturing and drying, they spread everywhere through airflow to reproduce their offspring.
Black fungus is a saprophytic fungus. It has no chlorophyll and cannot make its own food. It must rely on organic matter in other organisms as its nutrients. At the same time, it lives saprophytically and must grow and develop on dead organisms. Its mycelium has a strong ability to decompose cellulose and hemicellulose in organisms, and can ultimately break organisms down into fragments.
Under suitable conditions, the basidiospores of black fungus germinate into mycelium, or form conidia, and the conidia germinate to produce mycelium again. As the mycelium grows continuously, it gradually produces branches, and cross walls form in the branches, developing into tubular downy hyphae with only one nucleus in each cross wall segment, namely monokaryotic hyphae. This kind of mycelium, produced by the germination of a single spore, is distinguished by positive and negative sexes, and this mycelium is called primary mycelium or first-stage mycelium. Then, after the apical cells of two monokaryotic hyphae of different sexes come into contact and fuse with each other, a binucleate cell is formed, and the binucleate cell develops into dikaryotic mycelium through clamp connections. At this time, the mycelium grows and develops continuously, and produces a large number of branches that spread deep into the organism, absorbing large amounts of nutrients and water and preparing for further development into a fruiting body. Once conditions are ripe, it produces fruiting body primordia on the surface of the organism.
III. External Conditions Required for the Growth and Development of Black Fungus
In the process of growth and development, the external conditions required by black fungus are mainly nutrients, temperature, water, light, air, and pH. Among these, the factors with greater influence are water and light.
1. Nutrients: The nutritional requirements for black fungus growth are mainly carbohydrates and nitrogen-containing substances, and a small amount of inorganic salts is also needed. During growth and development, the mycelium of black fungus continuously secretes various enzymes, and therefore has a very strong ability to decompose wood or culture material. Wherever the mycelium spreads, it decomposes, obtaining the needed nutrients through decomposition and supplying the needs of the fruiting body. When we choose wood to cultivate wood ear, especially when choosing Qinggang oak from sunny slopes to cultivate wood ear, we do not need to consider the nutrient issue, because the nutrients in the trees are generally relatively sufficient and can fully meet the needs of wood ear growth. If sawdust or other substitute materials are used for cultivation, a small amount of gypsum, sucrose, and potassium dihydrogen phosphate, etc., should be added to meet the nutritional needs of black fungus growth and development. Nutrients are added once and supplemented a second time, referred to as "add first, supplement later."
2. Temperature: Black fungus is a medium-temperature type fungus. Its mycelium can grow and develop between 15°C and 36°C, but 22°C to 32°C is the most suitable. Below 14°C and above 38°C it is inhibited, but black fungus mycelium in wood has considerable resistance to short-term high and low temperatures.
The fruiting body of black fungus can form and grow between 15°C and 32°C, but wood ear grown between 22°C and 28°C has large pieces, thick flesh, and good quality. Wood ear grown above 28°C has slightly thinner flesh, pale yellow color, and poor quality. Although wood ear grown between 15°C and 22°C has thick flesh, black color, and good quality, its growth period is slow, affecting yield. Cultivating mycelium requires higher temperatures, while fruiting body growth requires slightly lower temperatures, referred to as "high first, low later."
3. Water: Water is one of the important factors in the growth and development of black fungus. Both the mycelium and fruiting body of black fungus need large amounts of water during growth and development, but the amounts required differ. Under the same suitable temperature, mycelium develops and colonizes relatively quickly under low-humidity conditions, while fruiting bodies develop rapidly under high-humidity conditions. Therefore, when inoculating, the moisture content of the ear logs is required to be 60%-70%, and the moisture content of substitute-material culture medium is 65%, which is beneficial for mycelial development and colonization. Although fruiting body growth and development require relatively high moisture, dry and wet conditions must be combined, and spraying should be done appropriately according to temperature. When the temperature is suitable, the relative humidity of the air at the cultivation site can reach 85%-95%, so that fruiting body growth and development are relatively rapid. When the temperature is lower, too much water should not be given, otherwise it will cause ear rot. The mycelium cultivation stage should be dry; fruiting body growth should be moist. That is, "dry first, wet later."
4. Light: Black fungus lives saprophytically, and light originally has little to do with the mycelium. Both mycelium and fruiting bodies can grow in dim, dark environments. However, light promotes the formation of black fungus fruiting body primordia, and ear buds can only unfold into vigorous ear pieces under a certain amount of direct sunlight. According to experience, when the ear yard has a certain amount of direct light, the wood ear produced is both thick and large and dark black, while in ear yards with alternating light and shade but no direct light, the wood ear produced has thin flesh, pale color, lacks elasticity, and appears less robust.
Although black fungus has a relatively strong tolerance for direct light, appropriate humidity must be provided, otherwise the ear pieces will shrink, dry out, stop producing, and affect yield. Therefore, in production management, it is best to create "dappled sunlight" for the ear yard to promote the rapid development and growth of fruiting bodies. In dark conditions, mycelium can form fruiting body primordia but they do not open. Only when there is a certain amount of scattered light do they open and form fruiting bodies. That is, "dark first, bright later."
5. Oxygen: Black fungus is an aerobic fungus. During the formation, growth, and development of the mycelium and fruiting body, it continuously carries out oxygen intake and carbon dioxide release. Therefore, the air circulation of the ear yard (indoor space) should always be maintained to ensure the oxygen needs of black fungus growth and development. Prevent stuffy environments and avoid ear rot and the spread of contaminating microorganisms. Mycelial growth requires little oxygen, while fruiting body growth requires large amounts of oxygen, that is, "weak first, strong later."
6. pH: Black fungus is suitable for living in a slightly acidic environment, with pH 5.5-6.5 being best. In wood ear cultivation with ear logs, this factor is generally rarely considered, because after stacking and sun-drying for fermentation, the ear logs themselves have already formed a slightly acidic environment. However, in strain isolation, strain culture, and substitute-material cultivation, this is a problem that cannot be ignored, and the pH of the culture medium (material) must be adjusted to a suitable level. In substitute-material cultivation, first adjust it to the alkaline side of the suitable range, and through natural fermentation it will reach the most suitable level. In short, the requirement is "alkaline first, acidic later."
IV. Production of Black Fungus Spawn
In the cultivation of edible mushroom spawn, we call the mycelium isolated from black fungus itself and from ear logs the "mother culture"; when the mother culture is expanded onto sawdust culture medium for cultivation, the resulting mycelium is called "stock culture"; and when the stock culture is propagated and cultivated into cultivation spawn, it is used for production.
Production spawn (cultivation spawn) culture medium, used for inoculating wood ear.
Formula A: 70 jin of branches (Qinggang oak branches), 18 jin of sawdust, 10 jin of bran, 1 jin of sucrose, 1 jin of gypsum, appropriate amount of water.
Formula B: 10 jin of cotton husk, 70 jin of wood shavings, 18 jin of bran, 1 jin of sucrose, 1 jin of gypsum, appropriate amount of water.
Preparation method: Except that for the branch spawn the branches are first soaked in 70% sugar water for 12 hours and then removed, and the wood shavings and bran are poured together and mixed evenly, and then the remaining 30% sucrose and gypsum are dissolved in water and sprinkled on top, while adding water and stirring at the same time, the remaining production method is the same as for producing mother culture.
V. Black Fungus Cultivation
1. Ear log cultivation:
(1) Tree selection: There are many tree species suitable for the growth and development of black fungus. However, suitable species should be chosen according to local conditions, using tree species that are abundant locally and easy for wood ear to grow on. Except for tree species containing pine resin, essential oils, alcohols, ethers, etc., and economic forest trees, all other tree species can be used to cultivate wood ear. At present, commonly used tree species include cork oak, sawtooth oak, Mongolian oak, warty birch, Castanopsis carlesii, Chinese wingnut, sweetgum, elm, black locust, willow, catalpa, plane tree, Chinese pistache, and so on. But cork oak and sawtooth oak are the best.
(2) Cutting trees: The historical custom is to cut trees during the "nine cold periods." Generally speaking, cutting can be done from when the leaves turn yellow and wither until before new leaves sprout, because this period is exactly the "dormant" period of trees. The nutrients in the trunk are in a state of accumulation and do not flow, there is less water, and nutrients are most abundant and concentrated. This is called cutting "sap-retaining trees." At the same time, trees cut during this period have bark and xylem tightly combined, and after cutting the bark does not easily fall off, which is beneficial to the growth and development of black fungus.
For the age of trees to be cut, those growing on sunny slopes should be 7-8 years old, and those growing on shady slopes or in poorer soil should be 8-10 years old. The trunk thickness is best around 10 cm, and the length is 1 m. One rack has 50 logs.
For the cutting method, the stumps should be left low, 10-15 cm above the ground; the axe should be applied from both sides of the trunk, and the stumps should be left in a "crow's beak" shape. This is beneficial for the regeneration of old stumps, and will neither accumulate water and rot the buds nor cause multiple buds to compete, affecting stump regeneration. When cutting, thinning the stump is advocated, and sweeping the stump is not advocated, because this is beneficial both for protecting young trees and for soil and water conservation.
(3) Branch removal: After the tree is cut down, do not remove the branches immediately. Keeping the branches and leaves can accelerate the evaporation of water from the tree and prompt the trunk to dry quickly, causing its cell tissues to die. At the same time, it helps the nutrients in the treetop concentrate in the trunk. Wait ten days to half a month before removing the branches. When removing them, use a sharp chopping knife and cut upward from below, close to the trunk, trimming them flat, trimming them into "copper coin scars" or "cow eye" shapes. Do not cut too deep and injure the cortex. After trimming, the scars are best smeared with limewater to prevent the invasion of contaminating microorganisms and water accumulation, and also to facilitate stacking and arranging in the yard.
(4) Cutting the trunk: In order to facilitate stacking, arranging, racking, management, and harvesting of ear logs, and at the same time to make it easy for ear logs to absorb moisture by lying close to the ground when laid down, overly long trunks should be cut into short logs 3 chi long. When cutting, use a hand saw or chain saw to cut them evenly, and smear with limewater to prevent contamination by microorganisms.
(5) Stacking and sun-drying: Stacking and sun-drying means selecting a high, dry, ventilated, sunny place for the cut wood logs, stacking them into piles about 1 m high in a "well" shape or "fish-back" shape, and letting them quickly lose water and die. During the stacking and sun-drying process, turn them inside out and upside down about every 10 days to promote even drying of the ear logs. The duration of stacking and sun-drying should be flexibly controlled according to tree species, thickness of ear logs, and climatic conditions. Generally, 1 month to 1.5 months of stacking and sun-drying will cause the ear logs to lose 30%-40% of their moisture compared with before stacking, and then inoculation can be carried out.
(6) Ear yard selection: The place where ear racks are arranged is called the ear yard. The quality of the ear yard environment is directly related to the growth and development of black fungus and its final yield.
Generally speaking, it is best to choose a wind-sheltered mountain hollow facing south with its back to the north. This place has long daily sunlight hours and small day-night temperature differences; morning and evening are often covered by cloud and mist, humidity is high, and air circulates, making it most suitable for the growth and development of black fungus. When selecting the site, it should also be close to a water source, which is beneficial for artificial watering. A slope of 15-30 degrees is suitable. Absolutely avoid places with rocky surfaces, chalk soil, or iron-alumina soil.
After the site is selected, it should first be cleared: thin out overly dense trees in the area, and cut away shrubs, thorny vines, and weeds that rot easily, leaving only a small number of broadleaf trees with small crowns or not-too-dense branches and relatively tall height, to provide appropriate shade for the ear racks in summer. Before cultivation, apply insecticide to the ground and disinfect once with bleaching powder, quicklime, etc.; in winter it is best to burn the site with firewood and grass. The sheep's beard grass, turf, moss, etc. growing on the site should not be removed, in order to prevent soil erosion and maintain the moisture of the ear yard.
(7) Inoculation: Inoculation means introducing artificially cultivated mycelial spawn into the sun-dried ear logs so that it develops and colonizes inside the ear logs and grows fruiting bodies. This is the most critical step in artificial cultivation of black fungus and is a major technical innovation in production. It takes effect quickly and gives high yields.
When inoculating, first disinfect the ear yard and ear logs (using disinfectant drugs or fire is enough; disinfect the tools used with alcohol or boiling water; workers can wash their hands with soapy water). Choose a shady place to do it, do not let direct sunlight shine on the spawn, and absolutely do not do it on rainy days.
The inoculation time is generally from February to early May, and in autumn it can be done between White Dew and Cold Dew. When inoculating, choose different tools according to different spawn types, such as branch spawn and triangular wood spawn; a chopping axe can be used to cut openings, and sawdust together with branches or triangular wood is stuffed into the cut openings, then lightly hammered tight with the back of the axe, with the principle of not falling out; for sawdust spawn and granular spawn, a 10 mm hand drill, hole puncher, or hollow punch can be used to make holes, and the spawn is inserted into the holes, covered with bark, and lightly hammered tight.
For inoculation density, the general row spacing is 2 cun, and plant spacing is 2.5-3 cun, arranged in a "" shape or alternately in a plum-blossom shape. The two ends of the ear logs should be denser so that the mycelium quickly occupies the position and prevents the invasion of contaminating microorganisms. The depth of inoculation should pass through the bark and enter the xylem by 3-4 fen.
(8) Stacking for colonization: Stacking is to maintain suitable temperature and humidity so that the mycelium quickly germinates, colonizes, grows, and develops inside the ear logs. This is an important step in whether inoculation succeeds. The method is: first choose a stacking location, clear the weeds, sprinkle a little insecticide or bleaching powder, rake it into the soil, then lay the inoculated ear logs flat and push them up, stacking them in a "well" shape or "fish-back" shape. The pile height is 3 chi, then cover tightly with plastic film, press down the surroundings with soil, and spread a ring of insecticide around to prevent ants from climbing the pile and eating the mycelium. The temperature inside the pile should be maintained between 22°C and 32°C, and the humidity between 60% and 70%. If the temperature is too high, lift the surrounding film to ventilate once and bring the temperature down. Turn the pile about every 10 days, that is, turn the ear logs thoroughly from top to bottom and inside to outside. Keep the temperature and humidity of the ear logs in the pile evenly maintained. The first turning does not need watering; after that, water once with each turning. If it can receive rainwater, so much the better. Colonization can be completed in about 1 month.
(9) Breaking up the pile and arranging in the yard: After the ear logs have been stacked for colonization, the mycelium has already grown out of the ear logs, so the pile can be broken up and arranged in the yard. The purpose of arranging in the yard is to let the ear logs absorb moisture by lying close to the ground, receive the sunshine, rain and dew and fresh air of the natural world, change their living environment, let them quickly adapt to the natural world, and prompt the mycelium to spread rapidly further inside the ear logs, shifting from the growth stage to the development stage. The method of arranging in the yard is to lay the ear logs flat on the ground, with the whole body close to the ground and not elevated, with a spacing of 2 fingers between each log. The site is best with some slope, so as to avoid water accumulating on the site after rain and flooding the ear logs. Turn the logs about every 10 days, that is, turn the side originally close to the ground upward to face the sky, and turn the side originally facing the sky downward to the ground, so that the ear logs absorb moisture evenly and avoid infection by moisture-loving contaminating microorganisms. In about 1 month, ear buds will sprout in large numbers, and then they can be racked.
(10) Racking management: When ear buds cover the ear logs, it shows that the growth and development of the mycelium has entered the fruiting stage. At this time, external conditions of "alternating dry and wet" are needed. After racking, its needs can be met, and contaminating microorganisms and pests that do not adapt to such conditions can be reduced. The racking method is to use a long pole as a crossbeam, support both ends with forked tree branches, then lean the ear logs obliquely against the crossbeam to form a "" shape, with a spacing of 2 cun between each log. Yield is calculated per rack of 50 logs.
The management work after racking is very important. As the saying goes, "three parts planting, seven parts management," and "whether there is a harvest depends on planting, how much is harvested depends on management." This shows the importance of management work.
Management work mainly includes removing weeds, contaminating microorganisms, and pests, and regulating temperature, humidity, air, and light. At noon in summer, try to avoid strong direct light shining on the ear racks. In winter, the ear logs that have just begun to fruit should be laid down so they can absorb moisture by lying close to the ground and keep warm, prompting early budding and early fruiting the following year.
(11) Harvesting and sun-drying: After the wood ear grows, it should be harvested frequently and selected carefully to ensure a bumper harvest. For spring ear and autumn ear, pick the large ones and leave the small ones, letting the small ears grow before picking them. For summer ear, pick large and small together, because summer has high temperatures, many pests, and rapid bacterial reproduction, which will cause mature ears to be eaten by insects and rot. The best time to pick ears is when the ears curl at the edges after rain clears, or in the morning while the dew is not yet dry and the ears are moist and soft. When brought back, they should be spread thinly on a drying mat and dried once under strong sun. During drying, do not turn them too much, to avoid causing curled ears. If there is continuous cloudy rain with no sun, first adopt the method of rushing to harvest and rush to pick, spread the wet ears brought back flat on dry thatch or dry wood ear, letting the dry thatch or dry wood ear absorb part of the moisture, and after the weather clears, move them out and dry them together. If you cannot rush-harvest all of them, you can cover the ear racks with plastic film so that the already-grown wood ear will not continue to be rained on and absorb water, causing log-flow loss.
2. Substitute-material cultivation: The continuous innovation of black fungus cultivation techniques has greatly increased both single yield and total output, but it still cannot meet the needs of foreign trade exports and the people's growing demand. With the promotion and development of artificial cultivation techniques, experimental research on the new technique of substitute-material wood ear cultivation was further promoted. At present, plastic bag cultivation is mainly used, and the method is as follows:
(1) Production process: about 40 days of cultivation spawn (plastic bag) after inoculation for about 2 months -> cultivation bag (plastic bag) opening holes -> ear buds form in 7-10 days -> mature and harvested in 15-20 days -> second ear buds form in 10 days -> mature and harvested in 15-20 days -> third ear buds form in 10 days -> harvested in 15-20 days.
(2) Select excellent spawn
The spawn for cultivating black fungus is obtained through domestication and screening from the spawn for log cultivation of black fungus. Therefore, not all spawn suitable for log cultivation can be used as spawn for substitute-material cultivation. The suitable spawn age for cultivation spawn is 30-45 days. Such cultivation spawn has strong vitality, can reduce contamination by contaminating microorganisms during the cultivation process, and can also enhance resistance to molds during cultivation. Generally, choose those with fast mycelial growth, thick and strong growth, rapid colonization after inoculation, short production cycle, high yield, large pieces, thick flesh, and deep color as spawn.
(3) Cultivation season: In Shaanxi and several nearby provinces, using natural temperature, cultivation can be done twice a year. In spring, start making stock culture in early January, make cultivation spawn in early February, make cultivation bags in mid-March, and produce ears in April, May, and June. In autumn, make cultivation bags in mid-August, and produce ears in September, October, and November.
3. Cultivation methods:
(1) Formula
Many by-products of agricultural and forestry products can be used to cultivate black fungus. Several culture medium formulas are introduced below:
① Sawdust culture medium formula: sawdust (broadleaf tree) 78%, bran (or rice bran) 20%, gypsum powder 1%, white sugar 1%, water about 65%.
② Cottonseed hull culture medium formula: cottonseed hull 90%, bran (or rice bran) 8%, gypsum powder 1%, white sugar 1%, water about 65%.
③ Corn cob culture medium formula: corn cob (crushed into granules the size of soybean) 70%-80%, sawdust (broadleaf tree) 10%-20%, bran (or rice bran) 8%, gypsum powder 1%, white sugar 1%, water about 65%.
④ Rice straw culture medium formula: rice straw (fresh rice straw crushed or cut into small sections) 75%, bran (or rice bran) 15%, sawdust (broadleaf tree) 8%, gypsum powder 1%, white sugar 1%, water about 65%.
If conditions permit, adding 2 percent soybean powder to the above culture media is even better.
(2) Mixing material and bagging: Weigh the above culture materials in proportion, mix evenly, dissolve the sugar in water and pour it into the culture material, add water and turn and mix, so that the moisture content of the culture material reaches about 65%. Or add water until, when the culture material is held in the hand, water lines seep out but do not drip. Then pile the material up, let it sit for 30-60 minutes so the material fully absorbs the sugar water, and bag it immediately. There are three bagging methods, each with advantages and disadvantages, and you can choose according to circumstances.
The first method: choose plastic bags about 5 micrometers thick, about 17 cm x 33 cm in size, with a square bottom. If flat-bottomed bags are purchased (the same as food bags), before bagging, first tuck the two bottom corners inward until the two corners touch. In this way, after filling with culture material, the bag is stable and can be placed directly on the cultivation rack. When bagging, put the already-mixed material into the bag, and while filling, vigorously shake it on a smooth place so that the culture material is compact and uniformly tight from top to bottom. At this time the height of the culture material is about 3/5 of the bag height. Wipe off the residual culture material in the upper part of the bag with a dry gauze, add a plastic neck ring (inner diameter 34 cm, height 3 cm), turn the plastic bag opening downward, tie it tightly with a rubber band so that its shape is like a glass bottle mouth, and plug in a cotton plug.
The second method: choose a cylindrical polypropylene plastic bag with a diameter of 13 cm, cut it to a length of 35 cm, tie one end tightly with cotton thread, then melt the film with candle flame or alcohol lamp flame to seal the bag opening. Fill the culture material into the bag from the open end, while filling, vibrate on the material pile, or press firmly with fingers, until filled to 5 cm from the bag opening, then twist the remaining plastic bag together, tie it tightly with cotton thread, and melt the film under candle flame or alcohol lamp flame to seal it. On a smooth tabletop, press the bag flat with the hand. Then use a 2 cm diameter hole puncher to punch a hole 2 cm in diameter and 1.5 cm deep every 10 cm on one side of the bag. Use scissors to cut the prepared medicinal adhesive tape into 3-4 cm square pieces and stick them over the holes. To make operation easier during inoculation, roll one corner of the adhesive tape into a double layer.
The third method: choose a cylindrical polypropylene plastic bag with a diameter of 13 cm, tie one end with string, fill the culture material into the bag from the other end, press the material firmly with the hand, until the material is filled to 5 cm from the bag opening, then gather the remaining plastic bag, tie it with string, and inoculate from both ends later.
It should be noted that no matter which bagging method is used, the material must be mixed, bagged, and sterilized on the same day.
4. Sterilization and inoculation: Place the filled cultivation bags in an autoclave for sterilization, maintaining 1.5-2 hours under a pressure of 15 kg/cm2, and when the pressure gauge drops to zero, take the bags out while hot and immediately place them in an inoculation box or inoculation room. If using a normal-pressure sterilization stove for sterilization, maintain 6-8 hours, wait until the bag temperature drops to 30°C, or fumigate with potassium permanganate and formaldehyde for 30-40 minutes to disinfect the space of the inoculation box or inoculation room. During inoculation, note that continuous inoculation should not last too long, to avoid the temperature inside the box becoming too high (exceeding 40°C); the inoculation amount should be larger, which can shorten the time for the mycelium to cover the surface and reduce the chance of contamination by contaminating microorganisms. As mentioned earlier, black fungus has relatively weak resistance to molds, especially Trichoderma, so sterilization must be thorough, and inoculation must be carried out aseptically to improve the finished product rate.
5. Mycelium cultivation: In the entire process of mycelium cultivation, conditions must be created that allow vigorous mycelial growth while also controlling the irregular stick formation of black fungus fruiting bodies. Among all conditions, temperature is the most important factor. The optimum temperature for the cultivation room is 22°C-25°C. Because the temperature of the culture material inside the bag is often 2°C-3°C higher than room temperature, the cultivation room temperature should not exceed 25°C. Especially in the later stage of cultivation (that is, when the mycelium has grown to more than about 1/2 of the culture material height), if the temperature exceeds 25°C, yellow water will appear in the bag. The water color changes from light to dark, and from thin to sticky. The production of this sticky liquid easily promotes mold infection. The relative humidity of the cultivation room should be 50%-70%. If the humidity is too low, much moisture in the culture material is lost, the culture material dries out, and mycelial growth is harmed. If the relative humidity exceeds 70%, contaminating microorganisms will grow on the cotton plug. Light can induce mycelium to twist together and form primordia. In order to control the mycelium cultivation stage so that fruiting body primordia do not form, the cultivation room should remain dark or have extremely weak light intensity. Sprinkle some quicklime around the cultivation room to make it an alkaline environment and reduce the chance of mold reproduction. When cultivation bags are placed on cultivation racks or piled on the ground to cultivate mycelium, they should not be turned too much. Because the volume of the plastic bag is not fixed, where the hand pinches, the volume changes and air is squeezed out of the bag. When the hand is removed, its volume returns to normal, and a small amount of air enters. In this way, contaminating microorganism spores may enter. In addition, where the hand contacts the bag wall, the pressure between the plastic bag and the culture material is increased. When encountering relatively sharp culture material (sawdust, cottonseed hull), it will pierce small holes invisible to the naked eye, and contaminating microorganism spores will also enter through this, increasing the infection rate. Therefore, during the cultivation process, move them as little as possible. When checking for contaminating microorganisms, be sure to handle them gently. If contaminating microorganisms are found, take them out promptly and place them separately in a cooler place for continued observation. If the degree of contamination is relatively light, inject formaldehyde solution into the contaminated area and stick a small piece of adhesive tape over the needle hole, which can control the further spread of contaminating microorganisms.
6. Opening holes: When the black fungus mycelium has fully grown in the bag, the fungus bags can be moved from the cultivation room to the growing room, the cotton plug and plastic neck ring removed, and the bag opening tied tightly with string; or the adhesive tape can be peeled off. Prepare two basins of 5% limewater. First place the bags in one basin and soak and wash them clean, then take them out. Use a blade to cut small openings on the surroundings of the bag at a spacing of 5-6 cm between two holes, with a length of 1-1.5 cm and a depth reaching 0.3 cm into the material. You can also first open holes on one side of the fungus bag. Soak the already-opened fungus bag in another basin of limewater so that the hole openings are in an alkaline environment, which can effectively prevent the harm of contaminating microorganisms.
7. Management during the ear-producing period: The fungus bags after opening holes can be placed flat on the fungus bed racks in the growing room, or hung on seedling bed racks or tree branches under the forest, or placed on the ground covered with wet sand, and then conditions for the formation of black fungus fruiting body primordia should be created. First, increase the relative humidity of the cultivation environment to 90%-95%, and keep the room temperature as much as possible at 20°C-25°C. Good ventilation and relatively strong scattered light are also indispensable conditions for the formation of black fungus primordia. At the openings, the mycelium can receive relatively sufficient light, air, and humidity, effectively promoting the formation of fruiting bodies there. Therefore, when cultivating black fungus by opening holes, the fruiting bodies all form at the openings or at cracks in the plastic bag. This is the so-called "directional ear production."
Under suitable conditions of temperature, humidity, ventilation, and light, generally 7-12 days after opening the holes, many small black dots can be seen with the naked eye at the openings; they gradually grow larger and join into one ear bud (young fruiting body). At this time more water is needed, a temperature of 15°C-25°C, relatively strong scattered light, and good ventilation. If continuous rainy weather occurs, the cultivation bags that have already formed ear buds can be hung in the open air, where temperature, humidity, light, and air can all be fully satisfied, and the ear buds develop faster. At this time, if green mold and orange-red Neurospora contamination are found at the ear base or on young ear pieces, the fungus bags can be carefully rinsed under a faucet to wash away the contaminating microorganisms, but do not wash away the fruiting bodies. Under suitable environmental conditions, about 10-15 days after the ear buds form, the ear pieces flatten and the fruiting bodies mature, and they can be harvested.
8. Harvesting and processing:
The standard for black fungus maturity is when the ear pieces are fully unfolded, begin to curl at the edges, the ear base becomes thin, and the color changes from black to brown. Then they can be picked. Frequent and careful picking is required, picking the large and leaving the small, so as not to cause ear flow. Mature ears left unpicked on the fungus bag are prone to pest and disease damage or ear flow. When harvesting, use a small knife to cut flat against the bag wall. The harvested wood ear should be sun-dried or oven-dried promptly. The drying temperature should not exceed 50°C. If the temperature is too high, the wood ear will stick together into lumps and affect quality. After the wood ear is dry, package and store it promptly to prevent mildew or insect damage. After harvesting, stop direct spraying for four or five days to let the mycelium accumulate nutrients. After about 10 days, the second batch of ear buds forms. Repeat the above management, and two more harvests can be obtained.
(VI) Prevention of diseases, insect pests, and contamination by contaminating microorganisms: At present, in the cultivation of black fungus, one of the most prominent problems is that there are many contaminating microorganisms on ear logs, many wood ear pests, and much contamination in spawn production and substitute-material cultivation, often causing undue losses to production. First, we must identify the causes and take preventive measures. Reducing losses can definitely be achieved.
The main causes of many contaminating microorganisms on ear logs are inadequate disinfection of the ear yard, ear logs, and tools used, poor ventilation in the ear yard, and long periods of stuffy air. Wood ear pests are mainly due to incomplete elimination of insect eggs in winter and untimely control in spring and summer. The contamination problem in spawn production and substitute-material cultivation is mainly due to contaminated isolated specimens, incomplete sterilization of culture media, poor disinfection of the boxes and tools used in the spawn introduction room, or incomplete sealing of the spawn introduction room and boxes allowing contaminating microorganisms to be brought in midway, the use of contaminated stock culture and mother culture, poor disinfection of operators' hands, work clothes, and hats, and so on. All of these can cause contamination and bring losses to production. Therefore, all staff are required, first of all, to attach importance to it ideologically, to check every link in sterilization and disinfection, to strictly implement all operating procedures, and never to be negligent in the slightest.
Some common disease and pest and contaminating microorganism names and preliminary control methods are introduced below for reference.
1. Contaminating microorganisms harmful to ear logs:
Black canker (Annulohypoxylon): black-brown granules, most likely to occur in high-temperature, humid, shaded places, often joining into one patch. The carbonaceous substance it secretes itself is hard, causing the cambium under the bark to turn black, preventing water absorption, and the inside becomes iron-hearted. Not only does it fail to produce wood ear, but even other contaminating microorganisms do not grow. It is the most harmful to ear logs.
Thelephora fungus: there are several kinds. One is called golden-edged moth fungus, which grows attached to the ear log, with edges turned up like eaves. The sterile surface attached to the wood is gray-red, and the surface is black, some looking like dried black fungus. Another is called cowhide hoop, of which there are black and white types, the black one chestnut-shell colored and the white one bamboo-shoot-slice colored, all growing tightly attached to the ear log, with edges not raised, resembling a sticking plaster, sometimes covering the whole ear log, causing powdery decay of the wood, and simply not producing wood ear. It is especially likely to occur in damp shade or continuous rainy days. There is also a wrinkled leather fungus, small chrysanthemum-shaped, resupinate, white, thin as paper, with a radial hymenium, wrinkles, or ridges. This kind is less harmful.
Polypores: one is called red fungus, bright jujube-red, sessile, half-moon-shaped, growing laterally on the ear log. It secretes dark brown pigment and can cause granular decay of the wood. Once this fungus grows, wood ear no longer forms. Another is called white fungus, white to pale cream colored, shaped like the red fungus but larger, sometimes overlapping in cloud-like layers, consuming large amounts of nutrients from the ear log, causing early decay of the ear log, and affecting wood ear yield. At the same time, this fungus is most prone to insects, and the small insects it produces also bore into and eat the ear log. There are also other larger boletes, white silk hair fungus, chicken feather fungus, yellow fungus (yellow nymphalid fungus), turkey tail, white-edged Penicillium, etc. These fungi are less harmful to ear logs, but are most likely to occur in stuffy environments.
For their control measures, first choose the ear yard in a ventilated, sunny place and do a good job of cleaning and sanitation in the ear yard; burn all decayed branches, weeds, and ear logs with contaminating microorganisms in and near the yard; spray the ear yard with insecticides and fungicides between Awakening of Insects and Pure Brightness; strictly disinfect the surface when inoculating ear logs, implement rational close planting, shorten the production cycle, and abolish the resting period in the mountains.
2. Common pests harmful to wood ear:
Red thread worm: body relatively thin like a thread, red, about 1 cm long, mostly boring into the ear piece from the ear base to feed, and not easily found on the surface. The bored ear piece becomes hollow inside, and irregular small holes appear on the surface. The bored ear pieces rot and flow easily and are unfit to eat. The harm is relatively great.
Fish worm: body shaped like a small fish, colored like a small shrimp; body about 1-2 cm long. It is the larva of a beetle, living inside the ear piece, gnawing outward from the inside of the ear piece, and also eating the ear base. The bored ear base no longer grows wood ear. This insect not only eats in the ear yard, but if brought into the warehouse it will continue to gnaw, with a relatively large appetite, and its feces are dark brown velvet-like strips.
Shell worms: there are many kinds of shell worms, but those more harmful to wood ear include black shiny shell worm, flower shell worm, sesame shell worm, etc. These insects crawl on the ear pieces and gnaw from the outside, like silkworms eating mulberry leaves, affecting the growth and development of wood ear. In severe cases they eat the whole ear piece clean, causing reduced yield.
Other pests include rice weevil, confused flour beetle, pine bark beetle, bagworm, springtail, slug, horse long worm, etc., and also fungus-eating insects in the ear base. In addition, termites, longhorn beetles, six-spotted jewel beetles, chestnut-colored jewel beetles, etc., which bore into and eat ear logs, also indirectly harm the yield and quality of wood ear.
The above pests generally begin to occur around the Spring Equinox and do little harm to spring ear. They occur in large numbers in the summer ear season and gradually decrease after the Beginning of Autumn. For control measures, besides doing a good job of eliminating insect eggs, for red thread worm and fish worm, use 1 jin of 50% wettable trichlorfon, add 1000-1500 jin of water, and soak the ear logs for 2 minutes; or use 1 jin of malathion, add 1500 jin of water and spray; for various shell worms, use 1 jin of derris powder and 0.5 jin of neutral soap, add 200 jin of water and spray; or use 1 jin of pyrethrum emulsifiable concentrate, add 800 jin of water and spray. For edible mites, use 1:1000 dilution of 20% wettable tetradifon (T-D-N) and spray; or soak ear logs for 5 minutes in a 1:800 aqueous solution of 20% wettable tetradifon. For jewel beetles, longhorn beetles, and longhorn beetle larvae, it is best to catch them manually in the morning and evening.
3. Contaminating microorganisms harmful to spawn production and substitute-material cultivation:
Penicillium: blue-green colonies, short downy, with uneven colony edges, conidiophores like brooms, with conidia also produced at the tips. It prefers low temperatures, mostly occurring around 25°C and in moist, poorly ventilated places.
Mucor and Rhizopus: these two fungi are similar in shape, with relatively long hairs. Mucor mycelium is white, and Rhizopus mycelium is gray-white and needle-shaped. Both produce black granular sporangia. If touched with the hand, the hand can be stained black-gray. Both fungi grow and spread relatively quickly in humid and poorly ventilated environments.
Aspergillus: there are two kinds, yellow Aspergillus and black Aspergillus. Their mycelium is relatively thick and short, and the spores all grow radially. Yellow Aspergillus is black-yellow, and black Aspergillus is yellow-black-gray. They spread quickly when the temperature in the culture medium is low.
Neurospora: mycelium is cottony, producing chains of spores, and the colony is bright orange-yellow. It spreads quickly when the temperature and humidity in the culture medium are high.
Trichoderma: mycelium spreads and grows, colony edges uneven, initially white; mycelium cottony or thread-ball-shaped. After maturing, clustered conidia form on the conidiophores at the branch tips. After spore production, the colony turns copper-green. It prefers dark, moist, poorly ventilated environments, and especially grows and spreads fastest under high temperature and high humidity.
Yeasts and bacteria: they are single-celled microorganisms; small in size and numerous in kind. After the culture medium is infected by these organisms, the surface becomes sticky paste-like or liquid-like, making the culture medium sticky and smelly, causing the mycelium to die.
To prevent infection by various molds, first attach importance to it ideologically, do a good job of environmental sanitation, and in spawn production and substitute-material cultivation, strictly implement operating procedures, check every link in sterilization, keep all tools, the spawn introduction room, boxes, and cultivation room clean and sterilized regularly, and have operators disinfect their persons before operation and then proceed. Never be negligent in the slightest.