Abnormal phenomena and treatment measures in the cultivation of Pleurotus ostreatus in late spring and early summer

Late spring and early summer are good seasons for cultivating Pleurotus ostreatus. However, due to improper operation, some mushroom farmers make the mushroom stick yellow and necrotic after fruiting, the culture material sour and smelly, and the mycelium grows full of bags, which makes the success rate, yield and quality decrease, which directly affects the economic benefit. According to many years of production practice and mass experience, the author summarizes the causes of abnormal phenomena and treatment measures as follows.

1. After the mushroom bag is produced, a large number of small mushrooms die.

In late spring and early summer, sometimes after the mushroom rod comes out, a large number of small mushrooms turn yellow and soft, the base becomes thicker, and then wither and rot into dead mushrooms. Reason: One is that after the formation of mulberry primordium, the temperature continues to exceed 30℃, resulting in the gradual withering of the cap, resulting in the death of a large number of small mushrooms; the other is that the culture medium is too dry, the relative humidity of the air is too low, and if the relative humidity of the air in the fruiting room or shed after the formation of young buds is lower than 80%, the small mushrooms will shrink and die due to the rapid evaporation of a large amount of moisture in the mushroom body; the third is poor ventilation, and the carbon dioxide concentration in the mushroom room (shed) increases rapidly. When it exceeds 0.5%, it will form large feet mushroom with thick handle or small cap. When the carbon dioxide concentration is higher, the young mushroom will be suffocated; fourth, too much water spray, so that the small mushroom body is easy to cause edema, and then turn yellow and fester, causing infection and death.

treatment measures

One is to take cooling measures when the temperature is too high during the fruiting period. Well water can be sprayed on the ground and surroundings of the fruiting room or shed to reduce the temperature to below 30℃. The outdoor mushroom shed should be thickened with straw curtain or straw shade, and ventilation management should be strengthened; Second, after the mushroom bag buds, the relative humidity of the air in the fruiting room or shed should be increased to about 90%. The water spray should be 4~5 times a day. The water spray should be small, fine, frequent and uniform each time. Do not spray water directly to the mushroom body when the young bud appears; Third, as the fruit body grows up, ventilation should be strengthened, especially in high temperature period, more attention should be paid to ventilation to ensure fresh air in the mushroom room or shed; fourth, the amount of water spray should be correctly controlled, neither without spraying water nor too much spraying water. To improve air humidity, spray water on the ground and walls frequently, and avoid spraying water directly on the young mushroom fruiting bodies as much as possible.

2. Only one end of the bag grows hyphae.

When the same strain is inoculated into both ends of a bag, only one end of hyphae grows well, and the other end shrinks and dies. Reasons: firstly, the sterilization stove is not reasonably built, and the condensed water cannot flow back into the pot along the stove wall, but irregularly flows into a part of the bag mouth, so that the culture material at this end absorbs too much water and inhibits the mycelium growth; secondly, the material bag is discharged close to the pot wall, the pot is too full of water, and the gap between them is too small, so that the steam circulation is blocked, and the condensed water flows into the bag mouth near one end from the stove wall, causing the culture material at this end to be too wet and affecting the mycelium growth.

treatment measures

First, the top of the stove is built into a circular arch, so that condensed water flows back into the pot along the stove wall; Second, there should be a certain distance between the discharge bag and the stove wall to avoid water inflow; Third, the material bag should not be overcrowded to accelerate the steam circulation and improve the sterilization effect; Fourth, the material bag with rubber band or string tie mouth should be loosened after mycelium planting to increase ventilation. It is best to use plastic collar and cover paper seal to avoid hypha death due to hypoxia. Fifth, a hole should be drilled in the middle of the bag, and the strains (especially wheat seeds) should be directly connected to the hole to avoid direct contact between the strains and the plastic bag and prevent the condensed water on the bag wall from soaking the strains.

III. Delayed fruiting after mycelium overgrows bags

Some fungus bags, hyphae growth is very vigorous, but hyphae grow full bag after the slow fruiting, some by 2 to 3 months still do not bud. Reason: One is the improper selection of strains. In late spring and early summer, medium and low temperature varieties were cultivated; secondly, the ratio of carbon to nitrogen of culture medium was not suitable; thirdly, when the mother seed was expanded, the aerial hyphae were picked too much, which caused the caking phenomenon of the original seed and cultivated seed, which would seriously affect the formation of fruiting body; fourthly, after the hyphae were full, under the condition of high temperature and low air humidity, the bag mouth was opened too early to form a dry thick bacterial film on the surface, so that the bacterial bud could not be differentiated.

treatment measures

One is late spring and early summer should cultivate high-temperature Pleurotus ostreatus varieties. If the cultivation of low-temperature varieties of Pleurotus ostreatus, should be the material bag at both ends of the tight, wait until the autumn temperature drops after the opening of the bag mushroom, can reduce losses. The plastic bag can also be removed, and the bacterial rods are tightly arranged in a damp and cool place, covered with a layer of crushed soil of about 2 cm, covered with straw curtains, and a large number of mushrooms can also be produced; the second is to reasonably prepare the carbon-nitrogen ratio in the culture medium. The optimum C/N ratio in the medium was 20:1 at mycelium stage and 30~40:1 at fruiting stage. If the ratio of carbon and nitrogen in the culture medium is out of balance, nitrogen is too much, carbon is insufficient, nutrient growth will occur excessively, hypha will form steep growth phenomenon, and even dense into clumps, forming fungus skin, inhibiting reproductive growth, delaying fruiting and affecting yield. Wheat bran, rice bran, potato and bean cake, corn and so on contain rich nitrogen, when adding should grasp the right amount. If the C/N ratio of the culture medium is out of balance, the bacteria with dense epidermis should be removed, and 0.5% glucose or (0.5~1) ×10-6 triacontanol and other carbon-containing substances should be sprayed to adjust the C/N ratio. At the same time, strengthen ventilation, illumination and increase temperature difference stimulation, so as to make it bud and mushroom as soon as possible; thirdly, the number of times of parent seed expansion should not be too much; fourthly, if thick bacterial film is formed on the surface of bacterial stick, holes can be poked at both ends of bacterial bag with iron wire, and then dry bacterial film on the surface can be scratched with small nail rake, and the bacterial bag can be immersed in water below 25℃ for 8~12 hours. After sufficient moisture is absorbed, it can be discharged on the rack again, ventilation, illumination and temperature difference stimulation are given, and air humidity is increased, and mushroom will also be produced quickly.

IV. Reasons for a large number of mushroom buds appearing in the middle of some bags:

One is that the loading is not tight, and there is a gap between the material and the bag; the other is that the pressure is too high during sterilization, and the material bag is broken or bulged; the third is that the material bag is punctured during loading or handling; the fourth is that the culture environment is not suitable during the mycelium growth stage, such as excessive temperature difference, strong light, high air humidity, etc., which will promote the production of fruiting body primordium in the middle of the material bag.

treatment measures

One is to compact while loading, tight outside and loose inside, so that the culture material is in close contact with the bag wall without leaving a gap; the other is to be careful when loading and handling, to avoid damage to the bag, and slowly deflate after steaming; the third is to create suitable environmental conditions for mycelium development. The culture chamber should be shaded, the temperature should be kept constant, and the relative humidity should be maintained at about 70%. The culture room should be separated from the fruiting field.

V. Causes of bacterial burning:

The temperature in the mycelium growth environment is too high. If the temperature of the culture room reaches 30℃ or more, it exceeds the range of mycelium vitality. When the room temperature reaches 40℃, the bacteria stick will burn and cause mycelium death.

treatment measures

The incubation chamber should be kept at a constant temperature, and the temperature should not exceed 30℃. When the temperature in the culture room exceeds 30℃, it is necessary to turn over the pile in time, ventilate and cool down. In order to avoid the phenomenon of burning bacteria, it is best to cultivate in cool indoor in summer. It is better to discharge the bacteria bag in a single layer, and insert a thermometer in the bag to observe the temperature change of the material. If the temperature is high, sprinkle some cold water on the ground in time, open doors and windows for ventilation, etc., and take cooling measures. It should be pointed out that the temperature in the culture medium is generally 3~5℃ higher than the room temperature, which should be noted.

VI. Reasons for fruiting under hyphae bag:

One is that the environmental conditions in the mycelium culture stage are not suitable, such as too dry or too wet culture materials; too tight pressure when loading; poor nutrition in the culture medium; too strong light; too large temperature difference; inappropriate pH; too old strain age, etc., which makes the mycelium vitality decline.

treatment measures

Create the best conditions suitable for mycelium growth and development, including ingredients, water content, pH, temperature, light, etc., all suitable for the needs of nutritional growth; second, select high-quality, white, robust and strong strains.

7. The culture medium becomes sour and smelly

After the culture medium is bagged and sterilized and inoculated with strains, the medium will emit a sour smell, which will affect the growth of mycelium. Reason: One is that the culture medium is not fresh and clean enough, with a large number of miscellaneous bacteria, especially the use of old materials, in the case of incomplete disinfection and sterilization, due to the proliferation of various molds in the material, so that the culture medium rancid, it produces a bad smell of sour smell; Second, the mixture of too much water, insufficient oxygen supply in the material, so that anaerobic bacteria and yeast take the opportunity to reproduce, resulting in the culture of decay and deterioration; hypha culture stage, due to material bag overlapping, material temperature increased, so that the growth rate of miscellaneous bacteria accelerated; Third, the wheat seed is in close contact with the material bag, and the condensed water on the bag wall soaks the wheat seed, so that the seed is rotten; fourth, the nitrogen nutrition in the material is too high, and chemical reaction occurs with the added lime to produce ammonia odor.

treatment measures

Firstly, raw materials should be selected before cultivation, fresh, clean, mildew-free and cake-free culture materials should be used, and exposed to sunlight for 2~3 days before mixing materials; secondly, water content should be controlled when mixing materials, and the ratio of cotton seed hull to water should be 1: 1.3~1.4, and the amount of water added to other crop straws should be 1: 1.4~1.5, and 0.1%~0.2% carbendazim or thiophanate-methyl should be added to water; Third, the culture medium with excessive sour smell should be poured out from the bag as soon as possible, and 2% lime water should be added to adjust the pH value to about 7.5 and the water content to about 60%, and re-seeding cultivation; fourth, if ammonia is too heavy, 2% alum water can be added to mix and deodorize. It can also spray 10% formaldehyde solution to deodorize; fifth, if the culture material has rotted and blackened, it can only be used as a high-quality fertilizer into the field and cannot be used for cultivation. Odor from cultivation sites can be removed by spraying deodorant. The deodorant formula is: ferrous sulfate 5 parts, sodium bisulfate 95 parts, ground into powder and fully stirred at normal temperature.