Key Technical Points for Mushroom Production from Standing Logs in Shiitake Log Cultivation
After a summer and an autumn of careful management, the mycelium of the mushroom logs enters the mature stage, and around the Beginning of Winter (Lidong), the logs can be set up standing for fruiting management.
The signs that the mycelium in the logs has matured are: the surface of the log shows no great difference from when it was felled, with no contaminating microorganisms and the bark tightly attached; when tapped with the back of a knife or with a finger, it gives a semi-dull or dull sound; the bark is soft and loose, and the wood beneath the bark is yellow or yellowish-brown and has the fragrance of shiitake; when pressed with a finger, the bark feels elastic and rough and uneven. There are also nodular protrusions, which are the prelude to fruiting, and sometimes a small number of shiitake mushrooms will appear, commonly known as "messenger mushrooms." At this point, the logs can be moved to the mushroom yard and set up standing for fruiting management.
The standing logs must be placed in an evergreen forest; if there is no evergreen forest, an artificial shed can also be used to increase shade and reduce direct sunlight. The method for setting up standing logs is to first drive two wooden stakes, place a crossbeam between them with the crossbeam about 60 cm above the ground (this can be adjusted according to the humidity of the mushroom yard), then lean the logs obliquely against both sides of the crossbeam in a ""-shaped arrangement, with the logs spaced about 10 cm apart, and leave a walkway between one rack and the next for management and harvesting. During the standing log stage, mycelial development and differentiation enter the fruiting body stage, and both the water content of the logs and the air humidity must be increased accordingly. Before the logs are set up standing, they should be soaked in water. There is no restriction on the soaking site, as long as the water is clean; the soaking time is about 24 hours, so that the water content of the mushroom logs reaches about 50-60%.
After the logs are set up standing, spray water in small amounts several times a day for 3-5 consecutive days. The spatial humidity should be between 80-90%. If external conditions are suitable, mushroom buds will appear within a few days, and under suitable temperature and humidity conditions, they can be harvested after 7-10 days.
During the fruiting period, strengthening water management is a very important task. If the moisture is too dry or too wet, it is unfavorable to the formation of primordia and the growth and development of fruiting bodies. If there is a long period of clear weather without rain, water should be sprayed once in the morning and once in the evening each day according to the degree of dryness or wetness of the logs, creating a certain temperature difference and moisture difference to promote the mass formation of fruiting bodies. After each batch of shiitake mushrooms is harvested, until the second batch of mushroom buds appears, spraying should be controlled to allow the mycelium to rest. This alternation of promotion and control is beneficial for high yields. If the logs are too dry, affecting fruiting, the logs can be soaked in a pool or mountain stream with relatively low water temperature for 12-24 hours, then taken out and gathered together, covered with plastic film to preserve warmth and moisture, and ventilated once a day, which can promote the mass emergence of mushroom buds. During the fruiting period, in order to maintain good air flow in the mushroom yard, the small shrubs and weeds around the logs must also be cleared away, and attention should be paid to ventilation and light penetration in the micro-environment.
Around the Spring Festival is the season for winter mushrooms to appear, and in management, attention should be paid to keeping the logs warm and protecting them from cold and freezing. From the Beginning of Spring (Lichun) to around Qingming is the season for spring mushrooms to appear; with continuous drizzle, contaminating microorganisms breed easily, so in management, attention should be paid to digging ditches around the mushroom yard for drainage and appropriately widening the spacing between the logs to facilitate ventilation and moisture removal. If it rains for a long time, a shed can also be built for covering to prevent the logs from becoming too wet and to reduce rotten mushrooms and the breeding of contaminating microorganisms.
Generally after Qingming, when the monthly average temperature reaches above 18°C, mushrooms rarely appear. After harvesting is finished, the mushroom logs should be stacked up as before, but because the logs have already used up part of their nutrients and the wood is not as tough as before, they must be handled even more carefully. The top of the stack should still be covered. However, there is no need to turn them; let the mycelium continue to grow for use in the next mushroom production year.
Log cultivation of shiitake mushrooms generally can produce for 3-5 years. In the first year, the yield is low; in the second and third years, it is abundant; afterward, it declines year by year. The yield of log-cultivated shiitake is usually calculated as the number of dry mushrooms produced per cubic meter of mushroom logs, and generally about 10 kg of dry shiitake can be produced per cubic meter of logs.