What environmental factors affect the appearance quality of bag-cultivated Ganoderma (reishi)?

Ganoderma, as a medicinal fungus, has its medicinal value and commercial value directly related to the quality of its fruiting bodies. Cultivating fruiting bodies with well-developed caps and good maturity is the ideal goal of medicinal Ganoderma producers. Ganoderma fruiting bodies are quite sensitive to environmental factors such as temperature, humidity, aeration and light. If conditions are unsuitable, deformed mushrooms are very likely to appear. Strictly regulating environmental factors is a necessary measure to improve the finished-product rate and appearance quality of Ganoderma.

1. Temperature factor

Ganoderma fruiting body primordia can form in large numbers at 25-30°C, form less and grow slowly below 22°C, and although they can form above 34°C, they very easily form nodular protrusions after primordium formation and stop developing; Ganoderma caps grow faster at 28-30°C, with sparser concentric rings and lighter surface color, while at 24-26°C the growth period is longer, more active ingredients accumulate, and the texture is harder, so Ganoderma grown at this temperature has better quality. To balance growth time and fruiting body quality, the room temperature during the primordium differentiation and growth stage is best controlled at (28±1)°C, and during the cap growth stage at (26±1)°C. In cultivation practice, the temperature control methods are: (1) arrange the mushroom emergence time appropriately according to local natural temperature conditions; in central and southern Hebei, early June to early September is more suitable; (2) when the temperature is 30°C, appropriate shading, sprinkling well water on the ground combined with ventilation, etc. can lower the room temperature by about 1-3°C; (3) production units with the means can use automatic temperature control equipment, for better results.

2. Humidity control

Ganoderma fruiting bodies have a demand for temperature characterized by high humidity and constant humidity. The suitable relative humidity is 90%-95%, and from primordium appearance to fruiting body maturity, the humidity should be kept relatively constant, so that the fruiting body can grow normally and evenly. However, because the fruiting body growth period is long, the temperature is high, and water evaporation is large, to achieve the required humidity, the ground or trenches must be watered 3-4 times a day, combined with misting water into the air space. If the humidity is normal, the top of the young mushroom or the growing part of the cap edge has a rounded, regular shape and is dark white; when the air is dry, this part turns grayish white, then yellow, while the surface becomes rough or uneven and loses its luster. Based on this, one can judge whether the fruiting body lacks water. If water shortage is found, mist water directly onto the fruiting body and combine this with watering (sprinkling) the ground (trenches). During the spore release period, avoid direct spraying onto the caps, and lower the indoor relative humidity to the lower level of 85%-90%.

3. Aeration regulation

Ganoderma fruiting bodies are very sensitive to the CO2 content in the air. According to measurements, during the fruiting body primordium stage, normal differentiation can occur when the CO2 volume fraction is less than 0.1%; when the CO2 volume fraction in the air is within 0.03%-0.06%, cap differentiation is faster and development is normal; when the CO2 volume fraction reaches above 0.1%, the cap is difficult to differentiate and form, and the stipe can lengthen and branch into an antler shape. Therefore, during fruiting body formation and development, good ventilation conditions should always be maintained indoors. To resolve the contradiction between ventilation and heat preservation, it is generally better to ventilate at night or early morning, or to maintain a slow airflow all day.

4. Light conditions

Ganoderma fruiting bodies are also very sensitive to light and have the characteristic of growing toward light. Light intensity and light source direction both have a great influence on fruiting body growth. According to measurements, when the light intensity is 4000-6000LX, the fruiting body develops normally, with thick and strong stipes and thick, large caps; when the light is stronger, the stipes are thin and small, and the cap does not differentiate or forms a small, thin cap. After the fruiting body primordium forms, the direction of the light source must not be changed arbitrarily, nor the position of the cultivation bags moved, otherwise normal fruiting body growth will be affected and deformed Ganoderma will easily form. If upright bag cultivation is used, in order to allow normal fruiting body development, generally after primordium formation, light is first admitted from the top surface so that the stipe extends upward; after the cap differentiates, the top surface is shaded and changed to single-side light transmission, so that the cap grows horizontally toward the light source. In this way, a regular fruiting body can be formed with the stipe perpendicular to the cap and the cap fan-shaped.