Key Management Points for Spring Button Mushrooms and Post-Harvest Handling Methods

The button mushroom (Agaricus bisporus) is currently China's largest export earner among edible fungi, with main production areas in Fujian, Shanghai, Hunan, Guangxi and other provinces. At present, it is the spring mushroom management stage, and some key management techniques for this stage are briefly introduced below:

Spring mushroom management accounts for about 30% of total yield. After mid-March, as temperatures gradually rise and stabilize above 10°C, the water content of the casing soil can be gradually adjusted to sufficient levels to meet fruiting needs. When adjusting water, first spray the clear supernatant of lime water at pH 8-9; when the temperature is below 15°C, top-dressing fertilizer can be applied together with spraying. Around April, when temperatures reach 15-25°C, this is the period when spring mushrooms flush heavily, and the amount of water sprayed should be increased. In May, temperatures often exceed 25°C, evaporation is high, and the spring mushroom season is about to end; the water content of the casing soil can be raised to its maximum limit, with about 0.5 kg of water sprayed per square meter of mushroom bed per day, to gain time to harvest the last batch of mushrooms.

The general principle of water adjustment for spring mushrooms is: steady in March, precise in April, heavy in May. Spring temperatures are unstable; when spraying water and ventilating, care should be taken to avoid cold waves and dry hot winds, so as to prevent mass mushroom death. Also spray lime water frequently to promptly adjust the continuously declining pH.

Post-harvest handling: Mushrooms are often harvested 5-7 days after pinning; when temperatures are low, they can be harvested 8-10 days after pinning. In Hunan and other southern regions, 2-3 batches can be harvested in autumn and winter, with the first flush having the best quality and highest yield. After the beds are rested in February, 4-5 more batches can be harvested in spring. Most mushroom varieties cultivated in China currently fruit in the 13-20°C temperature range, with neat fruiting and good quality at 16-18°C. Mushrooms should be harvested before the veil of the fruiting body breaks; after the veil breaks, they are open-cap mushrooms. Open-cap mushrooms are poor in quality and low in price, and have limited market outlets. After harvesting, mushrooms should have their stipes removed and be graded, then promptly transported to factories for processing or sold fresh. Transport packaging should include soft padding to prevent compression and bruising. At present, mushroom processing is mainly canning, followed by salt-preservation processing into brined mushrooms or slicing and drying.

Key technical points: China's mushroom yields per unit area are low. The ways to overcome this are: first, through the efforts of edible fungus researchers, breed high-quality, high-yield strains; second, introduce high-quality, high-yield strains from abroad. At present, the Ag2796 strain is commonly used in production, while promoting yield-increasing measures such as secondary fermentation, peat soil as casing material, and application of yield-enhancing agents.

Pests and diseases are an international problem in mushroom cultivation, seriously affecting mushroom yield and quality, and the principle of "prevention first, integrated control" must be implemented. The main control measures include: standardizing mushroom houses and keeping the environment clean; maintaining a reasonable carbon-to-nitrogen ratio in the compost and promoting secondary fermentation technology; selecting pure, contaminant-free, vigorous high-yield strains and sowing at the right time; sun-drying soil particles or treating them with 800-fold carbendazim before casing; properly handling the conflicts among temperature, humidity and air in the mushroom house; promptly and carefully removing sources of disease and pests such as diseased and pest-infested items, dead mushrooms and mushroom stipes from the beds; and rotating or discarding mushroom houses or idle shelving with severe pest and disease problems.