Summer Management of Shiitake Fruiting in Cool Greenhouses with Ground Cultivation

Shiitake fruiting management requires seasonal adjustments, with the core focus on temperature, humidity, light, and ventilation—plus the skillful use of "shocking" (tapping) to induce budding. Here is a streamlined overview:

1. Spring/Summer (May–June, First Flush)

• Strategy: Use natural rainy-season temperature swings to trigger primordia formation. Roll up greenhouse sheeting by day; spray water in the evening to cool down. Maintain 10–25°C, 85%–90% humidity, diffused light, and good airflow.

• Key Step: After buds appear, thin them to 6–8 per bag to ensure large, meaty mushrooms.

• Critical Rules: Use only drinking-quality water—wastewater is strictly banned. Spray in the cool morning or evening; midday spraying causes red rust spots on caps. Cover sheeting on rainy days to prevent dripping, but keep ventilation.

• After Harvest: Stop spraying and ventilate thoroughly (2 hours on sunny days, 4 hours on cloudy days). Allow 7–10 days of recovery. Wait until harvest wounds turn reddish-brown, then water heavily to initiate the second flush.

2. Summer (July, Peak Heat)

• Strategy: Focus on cooling. Use micro-misters, shade netting, and flood drainage ditches with cool mountain spring water up to log-base level.

• Induction Rule: Only "shock" (tap) logs when temperatures are below 27°C. Use a bamboo strip with a plastic slipper attached to gently tap the bag surface, breaking mycelial strands to let in oxygen and trigger budding.

• Warning: Never tap when the daily average exceeds 27°C—this accelerates nutrient depletion, causes rotting, and kills future flushes.

3. Early Autumn (August–November, Optimal Season)

• Strategy: With 20–30°C temperatures naturally favorable, prioritize moisture replenishment. Fill any cracks between logs with sandy soil.

• Operation: Use small nails driven 0.5–1 cm into logs to assist "shocking," then mist to create temperature/humidity differentials. Buds usually appear in 3–4 days. Mist 2–3 times daily (morning, noon, evening) and ventilate twice daily.

• Caution: During this period, natural temperature fluctuations will trigger budding on their own. Do not perform additional shocking, as this can cause an overwhelming flush of small, poor-quality mushrooms.

4. Recovery Period (Between Flushes)

• Principle: When remaining mushrooms drop below 15% of that flush's total, it's time for recovery. Withhold water, increase ventilation, lower bed humidity, and slightly raise ground temperature. After 7–10 days, once the mycelium in harvest depressions has regrown and turned reddish, spray once to induce the next flush.

5. Quick Reference – Common Problems & Solutions

• Bottom-growing "Landmine" Mushrooms: Caused by loose casing soil or excessive tapping. Remedy: Remove logs, clear bottom buds, refill gaps with casing soil, and flush with water to compact.

• No Mushroom Formation: Caused by thick mycelial skin, excessive light, or low humidity. Remedy: Gently tap thick-skinned logs, increase shade, and frequently spray well water to cool down.

• Excessive Budding: Caused by tapping too hard. Remedy: Always tap gently.

• Peziza Species (False Wood Ear): Cup-shaped fungi on the ground that deplete nutrients. Caused by high humidity and poor ventilation. Solutions: Choose high-elevation, well-ventilated sites; sterilize casing soil; dig out infected areas and fill with sterilized fresh substrate; spray infected spots with 0.2% bleaching powder solution when no mushrooms are present.

• Rotten Logs/Bags: Caused by unsterilized casing soil or overwatering. Solutions: Replace sandy soil annually, sun-dry the growing shed, scatter lime, and moderate watering.

• Mushroom Flies: Use yellow sticky traps and insect-attracting lamps (same methods as for oyster mushroom pest control).