Cultivation Techniques for Regulating the Size of Agaricus bisporus (Button Mushroom)

Because the production of Agaricus bisporus has developed very rapidly, mushroom output has soared, and with only a single channel for product consumption, buyers are extremely strict about fresh mushrooms (requiring a diameter of 2-4 cm), which has greatly affected production efficiency and growers' enthusiasm. As the mushroom planting season approaches, I would like to share my experience on how to control mushroom size.

1. Replace the strain. At present, the mushroom variety commonly used in Guangxi is the "As2796" strain, which is a large-fruited hybrid. Its main advantages are wide adaptability, strong stress resistance, large size, and high yield, but relatively few meet the buyer's purchasing specifications. If there is a supply contract, the small-fruited strains should be replaced in time, such as F56, F62, and others, which all belong to the small-fruited type. Although the yield of small-fruited varieties is slightly lower, the proportion of fresh mushrooms meeting purchasing requirements is relatively large.

2. Change the casing soil. The thickness of the casing soil layer directly affects the size of the fruiting bodies. Its mechanism of action is: as the casing soil thickens, the mycelium becomes densely distributed in the soil layer, but it is not easy for it to knot. Once it knots and forms primordia, the surrounding mycelium concentrates nutrients and water to supply it, which inevitably forms large fruiting bodies. If there is not enough time to replace the strain, it can be controlled by adjusting the casing soil layer. The normal casing soil thickness is 3-5 cm, and it can be adjusted to about 2 cm. In this way, mycelial knotting and primordium formation become dense, creating a certain survival competition situation, and it is not easy to form "large mushrooms."

3. Increase the temperature appropriately. The suitable growth temperature for mushrooms is generally between 15°C and 20°C. If the temperature inside the shed is appropriately raised by 1°C-2°C, the number of primordia can be significantly increased, growth speeds up, and most fruiting bodies remain at a medium-to-below-medium size. Its mechanism of action is the same as above.

4. Harvest early in a timely manner. When the fruiting body is visually judged to have grown to meet requirements, it should be harvested immediately. There is no need to wait until it is 70% to 80% mature before harvesting. Early harvesting may appear to affect yield, but the delivery rate is high, which invisibly increases commercial value, and it can avoid the fruiting body consuming too many nutrients by growing fully. The yield will be compensated for by an increase in the number of flushes, and the overall benefit will not decrease, but will instead increase somewhat.