Key Points for High-Yield Indoor Shiitake Mushroom Fruiting in Northern China

Traditional shiitake mushroom production involves moving the mushroom bags to outdoor mushroom sheds after color change or cultivating them with soil casing in beds for fruiting. The author placed shiitake mushroom bags indoors for fruiting management, saving time, money and labor, simple and easy to implement, achieving high yields. The method is described as follows:

1. Making the mushroom logs

① Mixing materials and bagging: The substrate formula is 60% coarse hardwood sawdust, 18% fine sawdust, 20% wheat bran, 1% white sugar, 1% gypsum. In northern China, production begins from February to the end of April. Mix the materials evenly, bag them at about 60% moisture content, with moderate tightness - when pressed with a finger, the bag should feel elastic and not sink in.

② Sterilization and inoculation: Place the bags into a steamer and raise the material temperature to 100°C, maintaining it for 12-15 hours. After sterilization, let them sit for 12 hours. When the material temperature drops to 70°C, remove from the steamer, transport the bags to the inoculation room and cool to 30°C, then inoculate on a clear morning or evening while the temperature is favorable, avoiding high temperatures. Strictly follow aseptic procedures to increase the rate of usable bags.

③ Mycelium running and color change: Place the inoculated bags in the room where fruiting will occur, stacked in a "#" pattern. When the mycelium has grown to 1/3, puncture holes for aeration; when fully colonized, puncture once more; the third puncture should be about 1 month after the second. Hang dark curtains indoors or shade nets outside the windows to block light. Ventilate regularly to dissipate heat and prevent high-temperature damage to the mycelium. Turn the stacks frequently, and sprinkle water to cool down when necessary, keeping the room temperature between 5-28°C, never exceeding 28°C. When the bag surface changes from white to pinkish to brown, with 2/3 of the surface showing nodular protrusions, the color change is successful.

2. Fruiting management

By the end of August to early September, after the Start of Autumn, when the room temperature is 10-25°C, fruiting management can begin. Rearrange the bags, shake them a few times to stimulate fruiting. After the Start of Autumn, the temperature difference between day and night increases; open the curtains to provide light stimulation. During the day, close the windows tightly and spray water in the room, keeping the temperature at 18-22°C and relative air humidity at 80%-85%; at night, open the windows, keeping the temperature at 10-15°C, artificially widening the day-night temperature difference and air humidity difference. In this way, mushroom buds appear after 3-4 days; at this point, cut the film to let the mushrooms out. Spray water daily, keeping indoor relative air humidity at about 85%, which allows 2-3 flushes of mushrooms. After November, when the temperature drops below 10°C, spray water to maintain moisture so the bags can overwinter. The following year when the temperature rises above 10°C, from March to April, inject water into the bags, add nutrients such as urea and mushroom nutrient supplements, and produce another 1-2 flushes. In this way, both mycelium running and color change, as well as fruiting, are done indoors, avoiding the need to transfer the bags, build mushroom sheds or beds, and the associated materials and labor - saving money, time and labor, simple and easy to implement, easy to promote, and highly profitable.