Precautions for Topdressing Edible Fungi and Methods for Identifying Diseases

In the late stage of fruiting of edible fungi, in order to enhance the fruiting capacity, mushroom growers often add nutrient solution for topdressing. However, only when the correct method is used can the expected goal be achieved; otherwise, the result will be the opposite and bring losses to producers. Attention should be paid to the method of addition. There are usually 3 methods for adding nutrient solution: spraying, soaking and hole irrigation.

1. Spraying method: The time for spraying the nutrient solution is preferably when the fruiting bodies appear in large numbers. When spraying, care should be taken that the nozzle is not directly facing the fruiting bodies, and attention should also be paid to the "four no-spray" rules: first, do not spray on small young mushroom buds, so as to avoid their "swelling to death." Second, do not spray on places where mushrooms have just been harvested or where mushroom residues remain, so as to avoid causing bacterial diseases. Third, do not spray when the air humidity is too high. Fourth, do not spray when pests and diseases are severe in the mushroom shed (room).

2. Soaking method: Mainly used for bag-cultivated edible fungi. After harvesting 1 to 2 flushes of mushrooms, if the cultivation bags are in a state of severe water shortage, they can be soaked in a prepared nutrient solution until they recover or approach their original weight. When using the soaking method to add nutrient solution, it is only necessary to place a heavy object on the bags after they are immersed in the nutrient solution, but the soaking time should not be too long. If the bags have lost too much water, they can be soaked several times.

3. Hole irrigation method: Mainly used on mushroom beds. This method can be used when the mushroom bed produces many mushrooms and the consumption of water and nutrients is too great. The specific method is: make holes in the mushroom bed at a spacing of 10 cm, flood the mushroom bed with the prepared nutrient solution, and cover with soil after adding the nutrient solution. The concentration should be appropriate. When the concentration of the nutrient solution is too high, not only is it difficult for the mycelium to absorb it, but it may also hinder or even damage the mycelium. When the concentration is too low, the effect is not obvious and the goal of high yield cannot be achieved. The concentration of the nutrient solution should also be determined according to the water content of the culture material. If the water content of the culture material is relatively high, the concentration of the nutrient solution should be increased, the amount of water used should be reduced, and after adding the nutrient solution, ventilation should be increased. Conversely, the concentration of the nutrient solution should be reduced and the amount of water used should be increased. The nutrients in the nutrient solution should be comprehensive. Several nutrient solutions should often be used alternately, so that the nutrition obtained by the fruiting bodies is both comprehensive and reasonable. If hormones are used to stimulate the growth of edible fungi, they should be used after supplementing the nutrient solution. Attention should be paid to changes in the environment. When the temperature reaches above 20°C, it is difficult for the mycelium to form high-quality fruiting bodies (except for high-temperature-type edible fungus varieties), so nutrient solution may not be added. If the culture material has already been contaminated by unwanted fungi, the unwanted fungi must first be removed before adding the nutrient solution. In order to prevent contamination by unwanted fungi, a certain amount of bacteriostatic agent can also be added while adding the nutrient solution, so as to prevent the breeding and spread of unwanted fungi.