Detailed Methods for the Prevention and Control of Slime Mold Disease in Bamboo Fungus
Once bamboo fungus (Phallus indusiatus) is attacked by slime mold, the losses are extremely severe, and mushroom growers everywhere should pay attention to this. This article provides a brief introduction to the damage symptoms, causes of the disease, and prevention and control measures.
1. Pathogen: The pathogen of bamboo fungus slime mold disease is Comatricha pulchella (C. Bab) Rost, also known as the beautiful hair net. Its form consists of sporangia growing in groups, sometimes densely packed, stalked, oval to cylindrical, slightly pointed at the top, dark brown or rusty colored, with a total height of 0.7-1.5mm; the stalk is black, generally shorter than the sporangium, rarely reaching half of the total height; the cyst base membrane is thin and membranous, disc-shaped and solitary, or a group forming a continuous sheet; the columella is straight, gradually tapering upward, nearly reaching the top of the sporangium; the capillitium is dense, curved, dark brown, with main branches relatively thick, branches gradually thinning, with many connections, few free ends, spores spherical, brown when in masses, with a diameter of 6.5-8cm.
2. Damage symptoms. Slime mold occurs on the bare soil of bamboo fungus beds or on the covering rice straw, and spreads rapidly. If the compost in the bed is infected, it will become moist and rot, with large numbers of bacteria and nematodes, causing the mycelium growth to be inhibited or gradually die out, and no more bamboo fungus will grow; bamboo fungus primordia (buttons) that are affected become water-soaked and moldy.
3. Causes of the disease. (1) High temperature and high humidity environmental conditions: Slime mold thrives in places rich in organic matter and with a moist environment. Especially under high temperature and high humidity conditions, spore germination and growth are rapid, and colonies expand very quickly, reaching up to 20cm in a single day, and can cover a large area of the bed within a few days.
(2) Compost infected with bacteria: Slime mold uses bacteria, organic matter, fragments of edible mushroom mycelium, and spores as nutrient sources, with bacteria being the best nutrient source. When bamboo fungus compost or bamboo fungus primordia are infected with bacteria, slime mold disease is very easily triggered.
(3) Soil, water sources, or air carrying slime mold.
4. Prevention and control. Adhere to the principle of "prevention first, integrated control".
(1) Use high-quality spawn that is pollution-free and highly viable. Spawn with off-odors or that is too dry, too wet, or too old should not be used.
(2) Pay attention to field plot selection and advance plowing, sun-drying, and sterilization. Choose field plots that face the sun, are well-ventilated, have fertile soil, and drain easily as the cultivation site. Clear the rice straw roots from the field plot 20-30 days in advance, and plow into beds for sun exposure. The drainage ditches around the beds must be clear, wide, and deep, so that rainwater does not accumulate. Spray 1:500 dilutions of dichlorvos and carbendazim 7-10 days before cultivation, and broadcast 25kg of lime per mu. On the day before preparing the beds and sowing the compost, repeat the above treatment with the same chemicals as required.
(3) Compost treatment. Sawdust, bamboo shavings, mushroom grass, spent mushroom substrate, etc. must be fully sun-dried. When laying down the compost for cultivation, place the raw materials into a water tank, add 2-3% bleaching powder, and soak for 24-36 hours, then remove and pile for fermentation for 5-7 days. During soaking or piling, add 0.3-0.5% lime and 1:500 diluted carbendazim to the water or material for sterilization.
(4) Strengthen bed management. Choose sunny days for laying compost and sowing. After sowing and covering with soil, scatter some bamboo leaves or spread rice straw on the bed surface, and insert arched bamboo strips, covering with plastic film to keep warm, retain moisture, and protect from rain; the shading materials around the mushroom shed should not be wrapped too thickly or too densely, and should facilitate ventilation; the bed ditches should not retain accumulated rainwater, the bed soil moisture should be maintained at 20-25%, the relative air humidity at 80-90%, and the light intensity at 600-800 lux.
(5) Treatment after disease onset. Once slime mold occurs on the bed, immediately stop spraying water, and increase light and ventilation in the mushroom shed. At the same time, remove the compost and soil from the affected area, and spread lime and spray fungicides. In the early stage of the disease, use carbendazim, thiophanate-methyl, copper sulfate at 1:500 dilution, and 100-200 international units of streptomycin or bleaching powder containing 150mg/L of available chlorine, and spray continuously 3-4 times.