Symptoms of Tumor-like Mushrooms and Detailed Explanation of Prevention and Control Methods

Enoki mushroom (Flammulina velutipes) mycelial tumors mostly appear after the first flush of mushrooms is harvested and before the second flush has formed. When they form, tumorous mycelial masses appear inside the cultivation bag and gradually grow larger, looking as small as broad beans and as large as eggs. The surface of the mycelial tumor is covered with fine root-nodule-like granules, each with a smooth surface, irregular in shape and varying in size. Some are a single mass, while others are several masses joined together. They are relatively hard in the early stage, and later generally begin to rot slowly when the temperature is above 18°C. They are not easy to spot in the early growth stage; only in the middle stage, when they emerge from the surface of the substrate or bulge the cultivation bag outward, can they be discovered. The reason tumor-like mushrooms form is mainly improper handling during bagging or transport and other steps, which creates voids or cracks inside some cultivation bags. In these voids, the substrate provides sufficient nutrients and suitable temperature and humidity, so fruit body primordia form inside the voids of the cultivation bag. Because other conditions in the voids cannot support normal fruit body growth, the fruit body primordia are forced to regenerate within the voids, growing more and more numerous and larger, thus forming mycelial tumor masses. During production, enoki mushroom mycelial tumors absorb large amounts of nutrients and water, and in the early stage they are not easily discovered, while in the middle stage they grow quickly, preventing the robust fruit bodies on the surface of the cultivation bag from growing normally and causing them to gradually shrivel. Even if a few enoki mushrooms can grow, their growth is very slow and the mushrooms are thin and weak. Once mycelial tumors appear, normal fruit bodies can no longer grow.

The prevention and control method is: when bagging, fill the substrate evenly and with uniform tightness; during transport, placement and other work, handle gently and do not stack, to reduce internal rupturing of the cultivation bags; manage scientifically and shift flushes in a timely manner to promote rapid growth and development of the fruit bodies.