Detailed Explanation of Key Management Techniques for Field-Grown Shiitake Mushrooms

1. Building the shed: According to the number of bags planted, build a spawn-running shed. Generally, every 10,000 bags occupy 120 sq m. The brightness inside the shed must not be too high, otherwise it will affect the normal growth of the mycelium.

2. Preparing materials: Calculated for 10,000 bags, 11 tonnes of wet coarse sawdust, 3 cubic meters of fine broadleaf sawdust, 2 tonnes of wheat bran, 100 kg of sugar, 100 kg of gypsum and various other materials must all be prepared and used.

3. Bag filling: (1) Thoroughly and evenly mix the coarse and fine sawdust, wheat bran and gypsum, and fully dissolve the sugar in water. Evenly sprinkle the water onto the mixed material. The amount of water depends on how dry or wet the sawdust is. The moisture content after mixing should reach 65%-70%. (2) Use a bag-filling machine to fill the material into mushroom bags of 53 cm x 15.2 cm. The filled bags should weigh 1.8-1.9 kg, and the tightness should be consistent from top to bottom. Packing too tightly easily causes the bags to burst, while packing too loosely affects the yield and makes the bags easy to break.

4. Sterilisation: Normally, atmospheric-pressure sterilisation is used, with 3,000-3,500 bags per batch. Use steam to bring the bags to 100°C and steam for 20 hours to kill harmful contaminant microorganisms in the material.

5. Inoculation: Cool the temperature to below 25°C in a sealed manner, and fumigate the already sterilised bags for 3-5 hours for further sterilisation. Afterwards, punch 4 holes on the front of each bag, stuff the spawn material in full and tightly, then seal firmly with adhesive tape.

6. Spawn running: After the inoculated bags have recovered at room temperature for 2 days, raise the temperature to 18-25°C for spawn running. Keep the spawn room clean. When the mycelium has grown to 10 cm, punch holes for oxygen release, and change the original arrangement of 4 bags stacked together to 3, so that air can fully enter the stack. When the mycelium grows to the back side, carry out a second oxygen release, with 18-22 holes punched. In the later stage of spawn running, the bags generate their own heat, and the temperature should be kept below 28°C.

7. Moving to the field: In June, remove the outer bags from the fully run spawn bags and move them into the already built small arched sheds, filling the gaps between the bags tightly and completely with fine sand. At the same time, use micro-sprinkler irrigation or manual watering so that the bags do not lose water; according to weather conditions, water 3-4 times a day. The density of the shade net over the fruiting shed should be above 90%.

8. Fruiting management: After 3-5 days of watering, the small mushroom buds will grow larger, and overly dense and deformed buds should be removed. As the buds grow, the amount of watering should be gradually reduced, otherwise the quality of the mushrooms will be affected. The fruiting shed must not exceed 25°C, and harvesting should be done according to the quality of the mushrooms collected, at least 3 times a day.

9. Management after the second flush: As the number of mushrooms decreases, increase the frequency of watering to replenish water, so that moisture is fully replenished and the mycelium can rest. After the mycelium has rested well, vibrate the logs with rubber or soft foam to stimulate fruiting. As the number of fruiting bodies rises or falls, the logs will shrink and cracks will form between them; promptly smooth over the cracks with fine sand.