Prevention and Control Methods for Contaminant Fungi in Mushroom Cultivation

The main contaminant fungi in mushroom cultivation are mainly Trichoderma viride, Aspergillus, etc., and are among the most common contaminant fungi in spawn production and cooked-substrate production. This type of mold prefers high-temperature, humid environments; for example, Trichoderma spores can survive long-term in soil and organic materials or in cracks in the walls of the growing shed, and spread through air, casing soil materials, tools, etc.

1. Preventive measures are: use Baibing Quwuzong to thoroughly disinfect and kill the mushroom shed; during the spawn-running and fruiting periods, spray a fungicidal agent about once every 5 days; in production, Baibing Quwuzong and Mushroom Bing-ling can be used alternately.

2. For a mushroom shed where contamination has already occurred, open all ventilation openings and entrances and exits to strengthen ventilation; at the same time spray Baibing Quwuzong, and then deal with the contaminated spawn bags.

3. For spot-type contamination: adopt the measure of injecting a 100-fold Xiaomei Wang solution to kill it; if the contaminant fungal spores germinate from within the substrate, then increase the concentration to about 50-fold, and insert the needle deeply, so that the medicinal liquid seeps out from the inside to the outside, and the killing effect can reach 100 percent. Note that the needle insertion point should be slightly above the contamination point, inserted obliquely, and after injection, the contamination point should be placed close to the ground.

4. For patch-type contamination: the method of injecting the drug can also be adopted, but the dosage should be increased, with the method the same as above.

5. For contiguous contamination: when it is difficult to inject the drug, cut a cross-shaped opening in the plastic film at the contaminated area, lift the plastic film, and brush on the medicinal liquid; this is only suitable for contaminant fungi that have germinated on the surface of the substrate, and it must be discovered early. Otherwise, the medicinal powder can be directly sprinkled on, and then the plastic film returned to position; its killing effect is good.

6. For contamination of about 50 percent of the area of a spawn bag: handle it flexibly according to the situation. If the edible mushroom mycelium has already grown to more than half, that is, the substrate has already been connected by mycelium, the plastic bag can be removed, and the spawn column soaked and washed with a prepared 150-fold Xiaomei Wang solution, then covered with plastic film for spawn-running culture; if the contamination is relatively severe and the amount of edible mushroom mycelium is relatively small, cut 3 to 5 slits lengthwise in the spawn bag, loosen the plastic film, and soak and wash, for a slightly longer time, then leave it to stand for spawn running.

7. If contamination occurs over a large area, the contamination time exceeds 15 days, and the contaminated spawn bags account for about 70 percent, then this batch of spawn bags has almost no retention value. After clearing all the spawn bags out of the shed, there are two handling methods: 1. Set up a sunshade shed, carry out normal disinfection and killing treatment, then subject the uncontaminated or lightly contaminated spawn bags to drug treatment as above, place them under the sunshade shed for spawn-running culture, and directly compost those that have lost culture value; 2. Empty out the material from the contaminated bags, and while the weather is fine, add lime powder at 2 percent of the dry material weight, mix well, and sun-dry it, to serve as raw material for cooked-substrate cultivation or fermented-substrate cultivation.

8. After clearing the shed, thoroughly clean up the sanitation, spray Baibing Quwuzong 2 times consecutively at an interval of 2 days, and remove coverings such as straw mats, close all ventilation holes and entrances and exits, and carry out sealed-shed treatment; after about 3 days of high-temperature sealed-shed treatment, a relatively ideal contaminant fungus killing effect can be achieved; then new bags can be brought in for culture again.