Latest Control Methods for Green Mold (Trichoderma viride) in Reishi Mushroom Cultivation
Green mold (Trichoderma viride) has the highest frequency of occurrence and degree of harm, and can occur at all stages of reishi mushroom cultivation. It can be described as a devastating and catastrophic disease and contaminant, seriously affecting the yield and quality of reishi mushrooms. It is the focus of disease control in reishi mushroom cultivation. Let us take a look together at the control methods for green mold in reishi mushroom cultivation!
Morphological Characteristics of Green Mold in Reishi Mushroom Cultivation
Green mold (Trichoderma viride) has slender, colorless hyphae that are septate and much branched. Conidiophores arise from the lateral branches of the hyphae, opposite or alternate, generally with 2 to 3 orders of branching, and the sterigmata bearing conidia are flask-shaped or conical. Conidia are mostly spherical, with the spore wall bearing small wart-like protrusions, green or blue-green in color. On PDA medium, the colony is initially white and cottony, later becoming dark green.
Damage Symptoms of Green Mold in Reishi Mushroom Cultivation
Green mold (Trichoderma viride) is widely present in various organic substances and soil in nature, and often floats in the air in the form of conidia. It has strong adaptability, and is especially prone to developing on substrates rich in lignin and cellulose. Once it infects, it grows and spreads rapidly, turning the entire substrate layer green. It also secretes toxins that destroy the host's hyphae and cytoplasm, inhibiting the growth of reishi mushroom hyphae. It competes with reishi mushroom hyphae for nutrients, consumes nutrients, and causes the host to die quickly.
Occurrence Patterns of Green Mold in Reishi Mushroom Cultivation
1. Transmission routes: Conidia are spread through airflow, water, insects, etc. Old mushroom houses, contaminated tools, and raw materials are the main sources of primary infection. The conidia produced after the disease develops can cause repeated re-infection multiple times.
2. Conditions for occurrence: Widely distributed in soil, air, and various organic matter in nature. Any substrate that is not thoroughly sterilized or poorly composted and fermented is very easily infected. At temperatures of 15 to 30°C, green mold spores have the highest germination capacity. The hyphae can grow within the range of 4 to 42°C, with the fastest growth at 25 to 30°C. A high-temperature environment favors spore germination and hyphal growth. It prefers a slightly acidic environment, but does not die even when the pH rises above 7.
Control Methods for Green Mold in Reishi Mushroom Cultivation
1. Select reishi mushroom varieties with good resistance to contaminants and strong hyphal growth vigor. Selecting high-quality reishi mushroom varieties is the key to successful cultivation. Varieties with good disease resistance and strong growth vigor are less susceptible to green mold infection.
2. Strictly select spawn for cultivation. The selected spawn must be pure in strain characteristics, with strong hyphal vitality, and the hyphae should be white, dense, robust, and of appropriate age, to prevent green mold from being introduced through the spawn.
3. Maintain good cleanliness and hygiene in the cultivation environment. Remove spent substrate and garbage from the mushroom house, thoroughly clean the cultivation racks, and carry out space disinfection to eliminate places where contaminants hide, thereby reducing transmission vectors. Good environmental hygiene can achieve twice the result with half the effort in preventing contamination.
4. The substrate should be fresh and free of mold. Sun-dry it for several days before use. The substrate formula should be reasonable, with the main ingredients and supplements thoroughly mixed. The moisture content should be controlled at around 60 to 70%, with an appropriate filling amount and moderate compaction. After filling, immediately carry out high-pressure or atmospheric-pressure sterilization to prevent acidification of the medium. Sterilization must be thorough.
5. Establish a strict aseptic mindset during inoculation. Since green mold spores float everywhere in the air, one must not be negligent just because they cannot be seen with the naked eye. The operator's hands, clothing, and all inoculation tools and materials used must be strictly disinfected. For example, operators using an inoculation room should wear caps to prevent green mold spores from landing on their hair. Inoculation movements should be as quick and skilled as possible to prevent introducing contaminants and contaminant spores during the inoculation process. Bags damaged during sterilization should be sealed with adhesive tape, and the seal should be disinfected with 75% alcohol.
6. Appropriately increase the inoculation amount, so that reishi mushroom hyphae can rapidly occupy the territory with absolute dominance, reducing contamination by foreign microorganisms and achieving the effect of suppressing contaminants through the mushroom itself.
7. Ensure that the cultivation room has a suitable microclimate, and manage the hyphal cultivation stage well. Control the temperature at around 25°C and the humidity at 60 to 70%, pay attention to ventilation and air exchange, strictly guard against high temperature and high humidity, create the most suitable environmental conditions for reishi mushroom hyphal growth, promote rapid growth of reishi mushroom hyphae, and rapidly occupy the entire substrate surface.
8. After the reishi mushroom primordia grow out, promptly remove the cotton plug or open the bag to prevent the primordia from being damaged and infected by green mold. Do a good job of heat preservation and moisture retention, while strengthening ventilation and providing a certain amount of light, to promote healthy growth of the primordia into fruiting bodies. Harvest the fruiting bodies promptly after they mature.