Autumn Management Techniques for Shiitake Mushroom Cultivation in Bags
Shiitake mushrooms have a relatively long fruiting period, generally starting in autumn and continuing until late spring of the following year, about 10 months. Generally inoculated in August to September, fruiting in November to December, and shiitake mushrooms grown before December are called autumn mushrooms.
Indoor Spawn Running
It takes more than 60 days from inoculation to physiological maturity. Therefore, after inoculation, they should be promptly moved into the spawn-running room for cultivation. The bags should be arranged in a “well” pattern, preferably 8 to 9 layers high, with room temperature generally controlled at around 25°C and relative humidity required to be below 70%. From 1 to 6 days after inoculation, the mycelium is in the recovery and germination stage, and room temperature can be controlled at 28 to 30°C. During this period, the bags must not be turned, no ventilation is provided, and doors and windows are shaded to create dim light. From 7 to 10 days, the mycelium begins to colonize the substrate, room temperature is lowered to 26 to 28°C, ventilation is provided 2 to 3 times a day, and the first turning is done on the 7th day, that is, the stacked bags are moved to swap upper and lower, inner and outer positions, so that every bag can receive management under the same conditions. When turning, handle gently and place carefully, strictly preventing damage to the sealed opening and infection by contaminating microorganisms. From 11 to 15 days, the mycelium grows vigorously and has extended to 4 to 6 cm, room temperature is maintained at 24°C, ventilation is increased, and a second turning is carried out. From 16 to 21 days, the mycelium grows and extends to 7 to 10 cm, room temperature should be maintained at 22 to 24°C, and the spawn stick is pulled out or the adhesive tape is lifted to form a gap, so as to increase oxidation and accelerate mycelial growth. After 21 days, use a bamboo skewer to poke holes to increase oxygen, making 4 slanted holes around the extending mycelium. The bag temperature should be controlled at 20 to 24°C and must not exceed 26°C. After 50 days, remove the shading material from doors and windows to promote mature and robust mycelial growth.
Bag Color Change
Management during the color-change period must be well handled, because the timing and quality of color change affect both the timing of fruiting and the level of yield. After the mycelium reaches physiological maturity, it changes from white to reddish-brown, and yellow water droplets appear, followed by the emergence of shiitake primordia. Therefore, during the color-change period, indoor diffused light should be increased, ventilation strengthened, and the plastic film opened and covered intermittently, so that the ranges of dryness-humidity and temperature are widened, forming an alternating dry-wet environment to promote color change. The purpose is to make the aerial mycelium lie flat and secrete pigment, forming a layer of reddish-brown, glossy mycelial film, which means successful color change.
Outdoor Mushroom Induction
Shiitake mushrooms are a low-temperature, temperature-variable fruiting mushroom type. After the bags change color, move the bags outdoors to a shaded place, cover them above and below with wheat straw as padding, and sprinkle water to moisten. Cover with film at night and uncover during the day, repeating for 4 to 5 days. Then cover with plastic film to seal the mushrooms and induce fruiting, the purpose being to widen the day-night temperature difference at the cultivation site and reduce ventilation, promoting primordium formation.
Fruiting Management
In autumn, the temperature gradually drops from high to low, and this temperature change pattern happens to match the temperature requirements for shiitake growth and development, which is favorable for robust mycelial growth. Three days after mushroom induction, select the bags. Pick out the bags that have fruited once a day and place them on the bed frames in the mushroom shed, with a bag spacing of 7 to 10 cm, until mushroom induction is completely finished. After the bags are placed on the bed frames, use a sharp knife to cut open the plastic film around the mushroom buds in 4 directions for mushroom resting. Generally, during the 7 to 10 day resting period, no film is covered. When the young mushrooms are the size of a peanut and feel firm when pressed by hand, flower induction can be carried out. If they are still loose, continue resting. Note that bags should be managed separately and resting continued until they are firm.