What to Do When Oyster Mushrooms Do Not Fruit? Cause Analysis and Control Measures

In oyster mushroom cultivation, it is common to see no fruiting or abnormal fruiting after spawning, which leads to production failure and reduced production efficiency. For this reason, after many years of production and research, we have summarized the causes of no fruiting or abnormal fruiting and the solutions.

1. Sterile spawn The fruiting bodies of oyster mushrooms are formed by dikaryotic mycelium. If the spawn used in production is unpaired monokaryotic spores or the mycelium grown from them, it will result in no fruiting or low yield. Therefore, before production, a fruiting test of the spawn should be carried out to avoid abnormal fruiting and economic loss.

2. Mixed spawn causing no fruiting If the spawn is not pure, mixed with other mushroom species or with strains of different temperature types, they inhibit each other and do not adapt to the cultivation environment, making fruiting difficult. In production, excellent spawn must be used to ensure spawn purity and prevent mixed spawn from causing no fruiting and affecting cultivation benefits.

3. Cultivation season not matching the temperature type of the variety Oyster mushroom varieties are divided into high-temperature, medium-temperature, low-temperature and wide-temperature types. Medium- and low-temperature varieties can no longer differentiate fruiting bodies when the spring temperature rises above 25°C. Growing high-temperature varieties in the low-temperature season will also delay fruiting. In oyster mushroom production, the temperature type of the variety must be chosen carefully, and a fruiting temperature test of the variety should be carried out before cultivation.

4. Improper formula of the cultivation substrate Oyster mushrooms obtain nutrients by decomposing the cultivation substrate through their mycelium. A suitable carbon-to-nitrogen ratio should be used in the cultivation substrate. During the mycelial growth stage, the C/N ratio should be 20:1, and during the fruiting body development stage, the C/N ratio should be 40:1. When the nitrogen source concentration is too high and the C/N value is too small, normal fruiting will be affected. When the water content of the cultivation substrate is below 40%, it will also cause no fruiting or abnormal fruiting after the flush. In production, the cultivation substrate should be reasonably prepared to create suitable nutritional conditions for oyster mushroom growth.

5. Poor light and ventilation, poor mycelial growth, difficult or abnormal fruiting Oyster mushroom mycelium does not need light for growth, but a certain amount of scattered light is needed during primordium differentiation. During the mycelial growth stage, it can tolerate relatively low oxygen pressure and can grow under semi-anaerobic conditions. During the fruiting body development stage, however, the demand for oxygen increases sharply, and it should be cultivated under well-ventilated conditions. The carbon dioxide content in the air should not be higher than 0.5%. When oxygen is lacking, fruiting bodies cannot form, and even if they form, many nodular protrusions may appear on the caps. Therefore, in production, a certain amount of scattered light should be provided during the primordium differentiation period, and ventilation should be appropriately increased to raise the oxygen level. If the mycelium on the surface of the cultivation substrate grows into an old mycelial skin and does not fruit for a long time, this indicates that the substrate surface is compacted. A small iron rake or similar tool should be used as early as possible to scratch the mycelial skin on the substrate surface in a shallow layer, with a depth not exceeding 0.5 cm. This can promote the mycelium to knot and fruit as soon as possible.

6. Improper temperature difference stimulation causing no fruiting The formation of oyster mushroom primordia requires stimulation by a temperature difference of 8-10°C. In production, because the environmental temperature is unsuitable and the day-night temperature difference is too small or too large, it is difficult for primordia to form. Fruiting is delayed or does not occur. In production, the temperature difference should be controlled to stimulate fruiting.

7. No fruiting caused by the influence of diseases and insect pests During the mycelial growth period, after weed molds contaminate the cultivation substrate, because oyster mushroom mycelium has strong vitality, it can cover the weed molds, but the weed molds are not removed. They compete with the mycelium for nutrients and secrete harmful substances, inhibiting normal growth of oyster mushroom mycelium and affecting fruiting body differentiation. After pests invade the cultivation substrate, they bite and eat the mycelium; the mycelium breaks, loses water and dies, disrupting normal physiological metabolism and material conversion of the mycelium, resulting in no fruiting. When fungicides and insecticides (such as carbendazim, dichlorvos, etc.) are used, too high a concentration or excessive use will also affect fruiting body differentiation. In production, observations should be made frequently during the mycelial growth period, and cultivation substrate contaminated by weed molds should be handled promptly. When using pesticides, be sure to pay attention to the concentration, method and timing of use.

In oyster mushroom production, as long as suitable varieties are selected according to the cultivation season and market demand, the cultivation substrate is reasonably prepared, and careful management is carried out according to the environmental condition requirements of each stage, avoiding the occurrence of factors that cause no fruiting or abnormal fruiting, high and stable yields will be obtained and production benefits will increase.