Emergency measures for pests and diseases in edible mushroom production

In the winter of 2007, infectious diseases, physiological diseases and insect pests of edible mushrooms occurred severely. The affected varieties also spread from oyster mushroom, shiitake, button mushroom, willow mushroom and shaggy ink cap to white ferula mushroom, king oyster mushroom, tea tree mushroom, enoki mushroom, etc. After brief classification and arrangement, the author summarized the main pests and diseases and their treatment measures, hoping to be helpful to cultivation. Infectious diseases Yellow mushroom: mostly occurs on varieties such as oyster mushroom, white ferula mushroom, king oyster mushroom and willow mushroom. It manifests as the caps of young mushrooms turning yellow, gradually expanding, until the mature mushroom stage, when the color becomes more intense, and in some cases slightly lighter, with the yellow appearing in patches, even spreading to the entire cap. This is mainly caused by bacterial infection. Poor ventilation, excessive humidity, etc. lead to infection and spread throughout the entire mushroom shed.

Prevention and control measures: stop spraying water, strengthen ventilation, especially from 10:00 to 14:00 on clear days, and at the same time spray a 300-400 times solution of Huanggu Yipenling for two consecutive days, once a day, to effectively inhibit the disease. Dead mushrooms: mostly occurs on varieties such as oyster mushroom, button mushroom, willow mushroom, white ferula mushroom and king oyster mushroom. It manifests as death at the mushroom bud stage, or death of young mushrooms, and some mature mushrooms also shrivel and die. It is mainly caused by fungal infection. There are many kinds of pathogens, and cross-infection often forms.

Prevention and control measures: remove dead mushrooms, scrape the surface of the substrate, and spray "Baibingsha" solution on the scraped substrate surface. According to the severity of the disease, use a 400-800 times concentration. On the basis of strengthening ventilation, 2 sprayings can inhibit or kill the pathogens. Mushroom bodies dying and becoming sticky: occurs on oyster mushroom, button mushroom, willow mushroom, white ferula mushroom and tea tree mushroom. The main manifestation is that mushroom buds can form in large numbers, but are difficult to differentiate. The young mushroom primordia begin to die, and the typical feature is that the mushroom bodies become sticky and give off a foul odor. This type of disease is caused by bacterial infection, resulting from severely poor ventilation and excessively high humidity.

Prevention and control measures: remove dead mushrooms, scrape the substrate surface, strengthen ventilation, reduce humidity, spray the substrate surface 1-2 times with Mushroom Disease Killer, spray the floor, walls and other surroundings with Baibing Quwuzong solution, raise the shed temperature during the day through sunlight and other measures, strengthen ventilation at night to lower the temperature, and widen the temperature difference. Generally, normal management can be restored in about 7 days. Severe contamination by weed molds: occurs in all varieties, especially in bags after the second flush or bags during the spawn-running stage, mainly Trichoderma, Aspergillus, etc. When northern regions enter winter management, the airtight and high-humidity environment allows weed molds to germinate and spread; enoki mushroom in Shandong and other places, and tea tree mushroom in southern areas such as Sichuan and Chongqing, are more prominently affected.

Prevention and control measures: strengthen ventilation, move contaminated bags out of the mushroom shed, prepare about a 300 times solution of Baibingsha, soak and wash the bags, then culture them separately. At a suitable temperature, if no weed molds reappear after about 10 days, they can be moved into the mushroom shed for normal management. White mold disease: mostly occurs on varieties such as enoki mushroom. The main manifestation of this disease is that the substrate surface and mushroom bodies are surrounded by white cottony fungal growth. In severe cases, the walls and floor of the mushroom shed are all covered with dense white mold, and the mushroom bodies gradually turn brown and rot starting from the base, with mushroom buds appearing later. This disease is downy rot. The pathogen prefers conditions with high carbon dioxide concentration, high humidity and stable temperature, but the pathogen is extremely intolerant to fungicides.

Prevention and control measures: generally, on the basis of strengthening ventilation, after picking diseased mushrooms, spraying clean water can also inhibit spread. In actual production, a 500-600 times solution of Baibingsha can be used, sprayed 1-2 times on the mushroom shed, combined with ventilation, to kill it. Physiological disease Dead mushrooms: this is the symptom that most commonly occurs in raw-material cultivation of oyster mushroom, willow mushroom, etc. The main manifestations are: the number of first-flush mushroom buds is normal, but they soon die, some turn yellow and then die, the dead mushrooms do not smell bad and are not sticky, and no pathogens are isolated in culture. The second flush is very difficult to produce, and even if it occurs it is sporadic and marginal, and most are difficult to grow large. Many mushroom farmers treat it as a disease, but all the medicines and solutions they can find are of no help. The reason is that this disease and the dead mushrooms of infectious diseases do not have the same cause. This disease is a physiological problem. The main cause is heating of the substrate during the spawn-running period, especially in low-temperature seasons. During spawn running, people are accustomed to stacking large piles and covering thickly. In Shandong and other places, some even cover with insulation quilts plus plastic film and let them run spawn. In the initial stage, the temperature inside the bag is about 15°C. The spawn germinates, colonizes and expands. As biomass increases, the temperature inside the bag continuously accumulates and rises, and cannot be dissipated. After reaching 20°C, the mycelium growth rate accelerates, and the product temperature (the temperature inside the bag) and the temperature between bags rise sharply. Once it reaches 30°C, substrate heating occurs and cannot be reversed. The author's survey results show that the low-temperature season is the main season for substrate heating. The higher the temperature period, the more attention people pay, so substrate heating basically does not occur. Once substrate heating occurs, there is no medicine available. In mild cases, a small amount of mushrooms can barely be produced to recover costs; in severe cases, it can only be treated and used as organic fertilizer.

Prevention and control measures: stacking can be done, but the product temperature must be monitored at all times. When it reaches or approaches 25°C, the stack must be immediately turned to dissipate heat. Never let it proceed naturally because of being busy, leading to substrate heating. No mushroom production: this problem also mostly occurs in raw-material cultivation. The basic cause is substrate heating, first substrate heating during the spawn-running period, and second substrate heating during the mycelium recovery period after the first flush when wall-type cultivation is used. It also occurs in cooked-material cultivation, mainly concentrated in wall-type cultivation. It also occurs in bed cultivation, and the main problem is also substrate heating.

Prevention and control measures: in production, generally do not use wall-type cultivation or bed cultivation. If it must be done, strict observation should be carried out. When the product temperature reaches about 25°C, corresponding measures need to be taken; otherwise, substrate heating is more likely to occur. Insect pests Mites: mostly occur on button mushroom, and some are also found on oyster mushroom. The basic symptoms are "difficult spawn running and mycelium regression." In some cases, spawn running is not completed after more than 40 days, and the surface mycelium becomes less and less, but it is often neglected as a disease.

Prevention and control measures: spray the bed surface with dicofol, tetradifon or other acaricides, then immediately cover with plastic film so that the pesticide can concentrate its effects in a small space. Phosphine tablets can also be used in combination, but safety must be noted, and it is best to use them under the guidance of technical personnel. Mushroom gnats: can occur on almost all varieties, but are most common on oyster mushroom, button mushroom, shaggy ink cap, etc., possibly related to the large cultivation area of these varieties. The basic damage symptoms are similar to those of mites, but the obvious difference is that white larvae can be seen when the substrate is opened for observation. Mushroom gnat larvae are slightly smaller, and mushroom fly larvae are slightly larger.

Prevention and control measures: fumigate and kill at a rate of 4 phosphine tablets per cubic meter of space. In specific operations, it can be applied at 1 tablet per 2 m of button mushroom bed surface, covered with plastic film; for bags, at 3 tablets per 200 kg dry material, placed into large bags made of wide double-layer plastic film, sealed for about 6-8 hours, and then ventilated. Similarly, when applying this chemical, it is best to have on-site guidance from technical personnel. Nematodes: mostly occur on varieties such as oyster mushroom, white ferula mushroom and button mushroom. The main manifestation is attacking the fruiting bodies, penetrating deep into the gaps between gills, absorbing mushroom nutrients and water, and destroying their marketability. This pest seems to become more rampant under lower temperature conditions, but in fact it is because the cultivation quantity is large in that season.

Prevention and control measures: soaking and washing bags with 2%-6% salt water or continuously spraying the bed surface can also effectively repel and kill them. Spraying with 5% formaldehyde is also possible, but due to residue concerns, it is generally not recommended.