How to grow the shaggy ink cap mushroom? A detailed guide to cultivation techniques using spent mushroom substrate

The shaggy ink cap mushroom (Coprinus comatus) is a rare edible fungus that serves as both food and medicine, rich in nutrients and with a unique flavor, and it is now widely cultivated across the country. In order to reuse the spent substrate (contaminated substrate) from edible mushroom production that is mainly based on cottonseed hulls, and to achieve better development of shaggy ink cap mushroom production in our county, we drew on the local conditions and, after several years of cultivation trials, developed a set of production techniques for cultivating the shaggy ink cap mushroom using spent edible mushroom substrate, achieving good economic and social benefits. The relevant techniques are reported as follows:

Raw material preparation: Take the spent substrate from edible mushrooms that have already fruited, such as oyster mushroom (enoki mushroom, straw mushroom), remove the bags and crush the bagged substrate, then sun-dry it for later use.

Seasonal arrangement: The season for cultivating the shaggy ink cap mushroom should avoid the hot, dry dog days of summer, and cultivation in spring and autumn is preferable. For spring cultivation, the fruiting period should be arranged for March to May; spring cultivation must follow one principle: the mycelium can only safely overwinter the summer after the bag is fully colonized. The autumn fruiting period is generally arranged for September to November. According to the temperature at fruiting time, a backward calculation method is generally used to determine the time for making the spawn bags; the colonization time is generally about 40 days.

Variety selection: The shaggy ink cap mushroom can be divided into clustered-fruiting types and solitary-fruiting types. Solitary-fruiting types have larger individual mushrooms, with a single mushroom weighing 30-150 g, but the yield is slightly lower; clustered-fruiting mushrooms have smaller individuals, with a single mushroom weighing 10-20 g, and the total yield is higher than that of solitary-fruiting types. At present, we mainly promote the clustered-fruiting type.

Cultivation method and site: There are many ways to cultivate the shaggy ink cap mushroom, but cooked-substrate bag cultivation with removal of the bags and soil casing gives good quality, high and stable yield, and no risk. Vegetable greenhouses are used for cultivation, covered with 1 layer of plastic film, then 2 layers of shade film or 1 layer of straw matting.

Substrate formulation: The spent substrate and contaminated substrate from cultivating edible mushrooms such as enoki mushroom and oyster mushroom are ideal substrates for cultivating the shaggy ink cap mushroom. Using these as the main ingredients and mixing in appropriate supplements for cultivation can not only increase yield but also reduce costs. The following formulas can be used for reference, with the specific choice depending on actual conditions.

1. Cottonseed hull 25%, oyster mushroom spent substrate 60%, wheat bran 10%, cornmeal 3%, sugar 0.1%, gypsum 1%, lime 2%; 2. Cottonseed hull 20%, straw mushroom spent substrate 57%, wheat bran 10%, rice bran 10%, gypsum 1%, lime 2%; 3. Cottonseed hull 20%, enoki mushroom spent substrate 56%, wheat bran 5%, rice bran 15%, lime 3%, gypsum 1%.

Spawn bag preparation: Choose any one of the formulas, weigh the materials, mix them evenly, make lime into limewater to mix the substrate, keep the moisture content at 60-70%, and then fill the bags. Bag filling can be done by hand or by machine. The bag specification is generally 17 x 33-38 x 0.04 cm, the filled substrate height is about 15 cm, and the wet weight is about 800 g. The bag mouth can be fitted with a ring and cotton plug, or the bag mouth can be folded and tied with string. The filling should be appropriately firm: if too loose, the mycelium tends to age and the moisture content is insufficient, affecting fruiting and yield; if too tight, there is insufficient oxygen in the bag and colonization is slow. After bag filling, sterilization should be carried out the same day. For atmospheric pressure sterilization, after the temperature reaches 100°C, maintain it for 8-10 hours, then let it sit for 4 hours before removing from the pot. The sterilized substrate bags should be placed in a disinfected room to cool. After cooling, inoculate in an inoculation box or inoculation room, following sterile operating procedures.

Colonization management: After inoculation, the bags should be handled gently and placed indoors for colonization. The temperature of the culture room is best controlled at about 25°C, with humidity below 80%. The number of layers in the stack of bags depends on the air temperature; when the air temperature is high, the number of layers should be low, and vice versa. Regardless of the height, be sure to note that the internal temperature of the bags is 2-5°C higher than the external temperature. For this reason, during the colonization stage, observe frequently to prevent overheating of the substrate, and at the same time strengthen ventilation and air exchange. If the bags are tied at the mouth, when the mycelium has grown over more than 1/3 of the substrate, loosen the bag mouth appropriately to increase oxygen and promote mycelial growth. Generally, the mycelium can fully colonize the bag in about 40 days; at this time, the temperature can be lowered to below 20°C for stacking, so as to rejuvenate the mycelium, store nutrients, and prepare for bag removal and fruiting.

Bag removal and soil casing: The fruiting of the shaggy ink cap mushroom differs from other edible mushrooms. Only through soil casing can fully colonized shaggy ink cap mushroom bags achieve high quality and high yield. Soil not only provides water and nutrients and plays a role in heat preservation and temperature regulation, but also stimulates fruiting through a large number of beneficial microorganisms. The quality of the soil directly affects the yield of the shaggy ink cap mushroom. It is best to choose soil with a certain amount of humus and good air permeability as the casing material, such as paddy field soil and vegetable field soil. The soil should first be sprayed with 2% formaldehyde solution and sealed for more than 12 hours, then the film should be removed and the soil spread out to sun-dry for 6-8 hours, and 2% quicklime water should be used to adjust the pH and soil moisture. When casing, make beds in the greenhouse, 80-100 cm wide and 15-20 cm deep, with unlimited length, and shape the bed surface like a turtle shell. Place the de-bagged spawn bags upright in the bed. To prevent contamination by foreign fungi and the occurrence of deformed mushrooms, spray the bed and surrounding soil with 5% limewater. When arranging the bags, leave a 3-5 cm gap between bags, then first fill the gaps with disinfected soil, water thoroughly, and then cover with a 3-5 cm thick soil layer on top.

Fruiting management: After casing, cover with plastic film and maintain humidity at 85-90%. To achieve such humidity, frequently spray spatial mist water over the bed when there are no small mushroom buds, increase the humidity in the greenhouse, and keep the casing soil moist but not sticky to the hand when squeezed. Lift the film once a day for air exchange. Generally, in 10-15 days the mycelium can penetrate the casing soil layer, and the surface becomes covered with "white fuzz." When the mycelium has covered the surface soil, remove the film. After 2-3 days, spray fruiting-inducing water to stimulate and promote mycelial knotting and differentiation of fruit body primordia. During the period of spraying fruiting-inducing water, ventilate heavily at the same time to reduce moisture on the soil surface and inhibit excessive vegetative growth of the mycelium; primordia begin to appear in about 1 week. Once small mushroom buds emerge, do not directly pour or spray water onto the bed surface, otherwise the small buds are very likely to rot and die. During the fruit body growth stage, there should be a certain amount of scattered light, and the greenhouse temperature is best controlled at 15-25°C. When the air temperature exceeds 25°C, promptly cover with thicker covering materials and irrigate the furrows to lower the temperature. The aerobic shaggy ink cap mushroom fruit bodies require a relatively large amount of oxygen during growth, so during cultivation management, lift the film frequently in the morning and evening, at the right time and in the right amount, for ventilation and air exchange, and maintain air circulation during the fruiting period. When ventilating, avoid strong wind blowing directly onto the bed, so as not to affect the color and quality of the mushrooms. The ventilation volume can be flexibly controlled according to the amount of fruiting.

Pest and disease control: The shaggy ink cap mushroom grows in a high-humidity environment, so there are many pests and diseases. The main pests include mites, mushroom flies, mushroom gnats, cutworms, and nematodes. Once pests are found during the fruiting stage, spray with beta-cypermethrin or mushroom pest cleanser once a day for 2-3 consecutive days. The main diseases include chicken-claw fungus, green mold, ink cap fungus, and weeds. The most serious is chicken-claw fungus. This contaminant generally occurs in the middle and late stages of the fruiting period. Chicken-claw fungus consumes nutrients in the substrate and also contaminates the soil surface, affecting the normal growth of the shaggy ink cap mushroom. After chicken-claw fungus occurs, yield is severely reduced, and in the later stage there may even be no harvest at all. Once chicken-claw fungus occurs on the bed surface, promptly remove it together with the substrate below it, put it in a plastic bag, take it out of the greenhouse, and bury it deeply. Sprinkle quicklime powder around the area where "chicken-claw fungus" occurred. For chemical control, spray with 700-800 times dilution of 50% carbendazim. For the control of ink cap fungus, sun-dry the substrate when mixing materials, mix with 0.2% carbendazim, and spray with 5% limewater, which can kill ink cap spores. After ink cap fungus occurs, pull it out immediately to prevent spread, or spray it with 5% limewater to inhibit its growth. In addition, changing to a new variety or a new cultivation and fruiting site can also effectively prevent or reduce the occurrence of diseases, especially the above two contaminants.

Harvesting and post-harvest management: The shaggy ink cap mushroom generally takes 5-10 days from small bud to maturity. When the temperature is high, it matures quickly; when the temperature is low, it matures slowly. When the fruit body reaches eight-tenths maturity, that is, when the ring on the edge of the cap has just begun to loosen and no recurved hairy scales have appeared on the cap, harvest promptly. At this time the mushrooms are of good quality, high yield, and good marketability, and the whole cluster should be picked at once. After harvesting, promptly clean the mushroom bed and add soil. After stopping watering to rest the mycelium for 3-4 days, water again, so that the mycelium has time to accumulate nutrients, improve the quality of the shaggy ink cap mushroom, and achieve concentrated flushes. Generally, 5-6 flushes can be harvested, and the biological efficiency can reach more than 100%.