Growing Room Requirements
Controlled environment rooms (temperature and humidity) are required for efficient production of high-quality mushrooms. Computer monitoring equipment to maintain the temperature and humidity at the required levels during the production cycle means high investment and is expensive, but streamlines production considerably.
Temperature and Humidity
Peak Heat
Raise the temperature to 60°c for several hours to pasteurize the compost. Afterwards to condition the product, compost and air temperature should be maintained at 49-52°c for several days. Ventilate the room, but do not allow the surface of the compost to become too dry. The humidity throughout this stage should remain between 90 and 100%.
Spawn Run and Casing
Maintain a room temperature of 25°c for 10-14 days with high humidity (95-100%). Ventilation is not required at this stage as high carbon dioxide levels encourage mycelium growth. Metabolic heat from the spawn will raise the temperature of the compost and it may require cooling. After casing, keep the surface moist and maintain constant temperature and humidity.
Harvest
Maintain an air temperature of 14-18°c in order to keep the compost at 16-20°c. In summer, this will require a cooling system. Ventilate well, avoiding fast or dry air currents. Maintain the humidity at 85-90%.
Cookout
At the end of the cropping season, use live steam to achieve a temperature of 70°c for 10 hours on the compost to prevent the spread of pests and diseases.
Spawn
Spawn is the mushroom propagating material, containing mushroom mycelium with a mixture of other materials to promote spawning. Spawn is commercially available from specialist spawn producers. Once purchased, it should be mixed with the compost as soon as possible, however, if required, spawn can be stored at 2°c for several weeks. Spawn performance can be adversely affected by excessive temperatures or rapid temperature changes.
Use 5-7L (3-5kg) of spawn per tonne of compost. Maintain the growing room temperature at 25°c and humidity at 95-100%. When a whitish growth covers the compost surface, the beds should be cased. From this point on, use detachable sideboards to monitor growth rather than digging through the casing layer.
Casing
A layer of specially prepared soil or peat moss is spread over the compost to protect it from drying out and allow for formation of the fruiting bodies. The preferred casing material is a mixture of peatmoss and lime. Soil mixtures require additional pasteurization and peat does not adhere well to the cap like soil does. Chemicals to assist in the aid of pest and disease control are often added to the casing mix. The soaked peat mixture should be drained until it no longer drips – do not squeeze. Do not allow the casing layer to dry out.
