What are the main causes of oyster mushroom yield reduction?
1. Poor-quality spawn: The quality of the spawn is key to successful cultivation. To reduce costs, many mushroom growers rely on their own experience to propagate mother cultures and production spawn, or buy spawn from private spawn stations with weak technical expertise and poor management. The spawn they produce is bound to have problems such as low vitality, easy degeneration, poor disease resistance, and low yield.
2. Improper variety selection: Variety selection for spring and summer mushrooms is especially important. Some growers, believing that high-temperature varieties have poor mushroom shape and only average yield, blindly choose broad-temperature varieties with better mushroom shape and yield for spring and summer cultivation. Once continuous high temperatures occur, the mushrooms fail to fruit.
3. Incomplete sterilization of the substrate: In cooked-substrate cultivation, if the substrate is not thoroughly sterilized, the contaminating microorganisms surviving in the substrate compete with the mushroom mycelium for nutrients, preventing it from properly decomposing the substrate and causing yield reduction or even complete failure of production. Many growers run into problems at this stage. Most of them have homemade atmospheric-pressure sterilization pots, whose tops have no vent holes, so steam struggles to rise to the top and escapes through side doors or gaps in the pot walls, leaving large dead zones; there are also no thermometer ports, so the temperature inside the pot cannot be accurately monitored, the sterilization time cannot be guaranteed, and the sterilization time is too short.
4. Rough inoculation technique: The inoculation process for cooked-substrate bag cultivation is almost the same as that for spawn production and requires aseptic operation. However, most growers do not have a dedicated inoculation room or spawn-running room. Some do it in greenhouses, air-raid shelters, or other cultivation sites with only some simple disinfection, inoculating by hand, running the spawn on site, or running spawn on one side while fruiting on the other. After years of cultivation, old mushroom sheds and air-raid shelters see a massive increase in various contaminating microorganisms and pests in the environment, making it very easy for diseases and pests to break out and spread.
5. Other problems: First, too high a proportion of lime in the mix affects the formation of oyster mushroom fruiting bodies. Second, some farmers seal the opening with only a single layer of newspaper, which cannot prevent contaminating microorganisms and is very easily damaged once damp. Third, during the growing period, in pursuit of yield, watering is too frequent and humidity is too high; once high temperatures occur, mushrooms rot and mold contamination appears.