Detailed Explanation of Key Points for Rapid Bud Induction in Bag-Cultivated Shiitake Mushrooms

The method of injecting water or soaking bags to induce fruiting in bag-cultivated shiitake mushrooms causes the water content inside the mushroom logs to become too high, and growers are kept busy for long periods cutting bag film to protect and nurture mushroom buds. In some cases, mushrooms fail to emerge for a long time after induction, missing the season for flower shiitake cultivation, which affects yield, quality and economic returns. A set of rapid bud induction methods is now introduced.

Directional puncturing: Use 4 iron nails 8-10 cm long, nailed into a wooden board 1.5 cm thick, 45 cm long and of suitable width for hand gripping, with the nails fully driven in. Use the nail row to prick two rows on the inoculation surface of the bud-induced mushroom log, with 2 rows of 8 holes on one side.

Vertical bag placement: Place the punctured mushroom logs vertically into a soaking pool or large barrel, with a maximum of 2 layers. Press them down on top with bamboo or wooden racks, then place stones or other heavy objects on top to prevent the logs from floating up.

Quantitative solution preparation: Using a graduated bucket or pool, prepare a 0.3%% urea solution, inject the prepared solution into the pool where the mushroom logs are arranged, submerging the logs 5-10 cm, and maintain the water level for 1 hour.

Timed bag soaking: Soak the mushroom logs for 1.5-3 hours. Among these, first-flush mushrooms are soaked for 1.5-2 hours; from the second flush onward, soak bags for 2-3 hours each time. After soaking for 1.5 hours, begin spot-checking the water absorption, with the water content around the nail holes at 65%%-70%% and other parts at 45%%-60%% being suitable, with the logs showing a state of locally higher water content and partially lower water content. Generally, the weighing method is used to determine water absorption, with the weight after the first soaking being 100%%-110%% of the weight of the log at cultivation time, and spring-planted bags at about 90%%-105%% of the weight at cultivation time. Thereafter, reduce the soaking weight by about 15%% each flush.

Temperature difference bud induction: Choose sunny days with day-night temperatures of 8°C-20°C to soak bags and induce fruiting; low temperatures below 12°C must occur at night, and medium-temperature strains require low temperatures of 14°C-16°C. Puncture a straight-line drainage hole at one end of the soaked mushroom log, with the drainage hole end facing downward, and arrange them on sunny, wind-sheltered ground that does not accumulate water, covering tightly with plastic film, and placing a thermometer on top of the mushroom logs inside the film. Use sunlight exposure; when the sunlight temperature is below 15°C or on overcast days, heating may be added to bring the temperature under the film to 28°C-32°C, maintain for 2-4 hours, lift the film for ventilation, then use the natural low temperature at night of about 12°C to stimulate for 4-6 hours. As long as temperature control is accurate, 1 time is sufficient. If the high and low temperatures are insufficient, it can be carried out continuously for 2-3 times.

Temperature regulation for bud nurturing: Mushroom logs that have undergone puncturing, soaking and temperature difference stimulation can remain in place, covered tightly with plastic film, with the edges pressed down firmly. Under conditions of 18°C-24°C, the bags produce large numbers of mushroom buds after 2-3 days. Generally, starting from the evening of the second day or the morning of the third day, select logs with more mushroom buds and place them on the lowest layer of the fruiting shed. Thereafter, select 1 batch every 12-24 hours, placing them into the fruiting shed from bottom to top, completing all within 2-3 days.

Precautions

① The water content of mushroom logs induced by the above method should be 35%%-55%%. For logs with water content below 35%%, a small amount of supplementary water should be added in advance to nourish the mycelium; for logs with water content above 55%%, the soaking time should be appropriately shortened or no soaking should be done.

② During the entire heating process of temperature difference bud induction, checks should be made every 30 minutes. If it exceeds 35°C, cooling should be carried out immediately.