How to solve mushroom spawn contamination? Master these key points

Mushroom spawn production is the prerequisite for mushroom cultivation, and high-purity spawn is the key to a bountiful mushroom harvest. With the great development of the mushroom industry, spawn production has been continuously expanding, and the economic losses caused by spawn contamination have also been increasing exponentially, which has become a problem that cannot be ignored in mushroom development. Starting from each link in spawn production, objectively analyzing the causes of contamination, and adopting corresponding preventive measures can achieve the goal of reducing spawn production costs and improving spawn quality and yield. The following measures can be taken to reduce mushroom spawn contamination:

Reasonably arrange the inoculation time for mushrooms

In the humid environment of summer, if the temperature is suitable, contaminating microorganisms multiply and spread quickly. July to August each year is the suitable season for making mushroom stock spawn and cultivation spawn, but during this period high temperatures and heavy rain are common in various places, contaminating microorganisms are very active, and it is also the period when spawn is most severely contaminated. In the high-temperature season, moving the inoculation time of mushrooms earlier or later is an economical and effective way to reduce contamination by contaminating microorganisms. The specific method is to inoculate during the lower-temperature time periods in July to August, such as in the morning or at night. Of course, inoculating indoors with air conditioning is even better.

Scientifically prepare mushroom spawn substrate

For the substrate used to make stock spawn and cultivation spawn, the raw materials should be fresh, clumped and caked materials should be broken up, and substrate that is difficult to absorb water should first be moistened with enough water, then thoroughly mixed. Mixing 0.1% to 0.2% carbendazim wettable powder into the substrate can inhibit the growth of Trichoderma and Penicillium. When using normal-pressure sterilization, after mixing the substrate it should be promptly filled into bottles (bags) and put into the steamer for sterilization; the resting time should not exceed 5 hours.

Sterilize mushroom spawn thoroughly

In the sterilization pot, test tubes should be placed upright, bottles (bags) should be arranged with gaps left between them, and cotton plugs must not press against each other. According to the substrate and container setup, determine the sterilization steam pressure (or temperature) and sterilization time, pay attention to expelling cold air, and the release of air should be slow.

Strictly make spawn in a sterile inoculation room (box)

Every operation step must be carried out strictly according to sterile operating procedures; after entering the inoculation room, move around less and speak less. After the substrate bags are sterilized, move them when they have cooled to the point of not being hot to the touch, which can reduce cracking of the bag walls. The inoculation environment should be clean, and the inoculation room (box) should be sealed and strictly disinfected. Inoculation tools should be kept clean and disinfected before use; damp cotton plugs should be replaced with sterilized dry cotton plugs.

Be careful when making mushroom mother spawn

According to the nature of the substrate, cultivation time, sterilization method, etc., choose suitable bottles or bags, fill the substrate to 2 to 3 cm from the cotton plug, wipe the mouth of the bottle (bag) clean, and then add the cotton plug to avoid contamination by moisture and substrate. When making mother spawn, be careful when pouring in the culture medium, and never let the culture medium stick to the mouth of the test tube. The cotton plug should be neither too loose nor too tight; if it is too loose, contaminating microorganisms can easily enter.

Choose mushrooms with robust mycelium as stock spawn

Choose pollution-free, robustly growing mother spawn and stock spawn of the appropriate age, inspect them carefully before inoculation, and do not use surface-layer spawn for inoculation. When inoculating, it is best to break open the bottom of the bottle and inoculate from the lower part up to 2 to 3 cm from the surface. If taking spawn from the bottle mouth, the upper 2 to 3 cm of spawn should be dug out, and then inoculation should be carried out.