Identification and Control of several Edible Mushroom Diseases

I. the causes of abnormal mushrooms and the measures to avoid them.

It is a common problem that deformed mushrooms reduce the product grade, even lose the commodity value, and affect the economic benefits of cultivation. Common malformed mushrooms are: mushroom lid clasping and showing "fist shape"; stalk long and thick, lid small, showing "vase shape"; lid sunken and edge cracked outer roll, showing "broken bowl"; lid narrow and long, showing "ox tongue shape"; lid surface spots, showing "hemp shape"; tumour protruding in the lid, showing "bloating abdomen"; two lids spreading side by side, handle tightly connected, showing "butterfly shape"; lid curved uneven, showing "wavy edge". Cover round wrap, fold contraction, showing a "bald"; cover longitudinal cracks in the groove, showing a "mushroom shape"; several mushrooms are symbiotic, showing a "lotus shape"; in addition, there are mushroom body atrophy, mushroom body yellowish discoloration, and so on. The reason for the occurrence of deformed Pleurotus ostreatus is that the culture environmental conditions do not meet the physiological and biochemical requirements of Pleurotus ostreatus. The key lies in the poor coordination of temperature, humidity, light and gas during the mushroom emergence period, operational errors in management technology, and so on. The following is a specific analysis, and puts forward the corresponding measures to avoid the occurrence of deformed mushrooms.

1. The structure of shed is unreasonable.

Many of the existing cultivation sites of Pleurotus ostreatus (indoor mushroom house and field mushroom shed) are poorly constructed and the structure is unreasonable. Some mushroom houses have one-way doors and windows, and some vents are opened in the upper half of the wall, resulting in poor indoor air circulation; some plastic sheds have vents on both sides, but vents are facing both ends of the fungus wall; and some have vents, but in order to keep warm, they are never opened. Due to poor ventilation in the shed, resulting in serious hypoxia, resulting in gas-loving Pleurotus ostreatus into deformity. The ideal mushroom shed should be sitting north to south or west to east. From the point of view of heat preservation and ventilation, the cultivation shed should not be too large, and the general rectangular shed should hold 3000 bags (15 × 8 × 2.2m) or 5000 bags (25 × 8 × 2.2m). The vents should be arranged below the long sides, bricked into 24 × 24cm caliber, one every 1m, and the openings on both sides of the vents are equal in height, which is beneficial to air convection. The door membrane at both ends of the mushroom shed should be able to open and close, which is conducive to longitudinal air convection; the roof should be covered with no dripping film plus grass curtain or sunshade net.

two。 Improper stacking of bacterial wall

Its performance: the bacterial bag into the shed wall is too high, 10 bags 1 yard, more than 1m; some bacterial walls are filled with clayey soil, which is impermeable; some are underwatered and dry after filling; some bacterial walls are palletized too dense and do not fill the soil in the middle; when some are built on the wall, the bag head cuts the film improperly, the part that enters the wall only cuts 1x3 too little, while the exposed end cuts the film instead, and the mycelium is exposed and does not moisturize. As a result, the growth and development of the fruiting body must be inhibited. For example, the wall of the bacterial bag in the north is insufficient, the water content in the bag is low and dry when heating and budding in the cold winter, and the water content in the bag is absorbed by the filling, so that the mycelium is dehydrated, which will inevitably lead to deformed mushrooms in the state of unstretched or shrunken cover; on the other hand, the clayey soil can not regulate the mycelium, but hinders the normal physiological reproduction.

In the mushroom area north of the Yangtze River, the mushroom bag wall is the carrier of Pleurotus ostreatus, which includes two aspects: bacterial bag and soil filling. The purpose of filling is to make use of the organic matter in the soil and regulate the temperature and humidity at the same time. The soil can keep warm at low temperature and dissipate heat when the temperature is high, which is not only a kind of soil-covering cultivation mechanism, but also a current mode of field cultivation of Pleurotus ostreatus in greenhouse. In order to achieve timely and good mushroom production, according to the practical experience of large-scale production in Guangshui City, northern Hubei, the "five essentials" must be achieved: ① time should be completed in the first and middle of December after the bacterial bag is physiologically mature, so that it can be transferred to bud acceleration; ② stacking wall should be stable, with 6-7 layers of bacterial bag palletizing, inclined shape, large bottom and small bottom, suitable for bottom width 120cm, upper width 80cm, wall length 280cm; the distance between bacterial walls should be 60~80cm operation road. The purpose of ③ membrane cutting is to cut the film inward to one end of the bacterial bag, which is to connect the mycelium to the fill, and it is suitable to cut off 2 pachy3; when stacking the wall, the two bags are discharged side by side, and the distance between the bags is 4: 5 cm; 1.5~2cm is left at the exposed end, which can not be cut, which can protect the mushroom; the ④ fill should be well built with clay, but the soil between the bacterial bags should be made of clay Gaza loam, mixed with 1% lime and 0.5% compound fertilizer to form nutritional soil. It is divided into two parts, one part is mixed with water into a mud shape for the base bag, the other part is dry mixed, it is used to fill the gap between the bags, and then watered; after ⑤ is filled with soil at the top of the stomatal bacteria wall, it is surrounded with mud to form a deep water level around 10cm, and every 40~50cm is hit a 3cm wide and deep until it is 2-3 bags away from the bottom of the bacteria wall, which is used as both ventilation and irrigation.

3. Congenital nutritional defect

There are four kinds of performance: the raw material cottonseed hull and wheat bran in ① formula are aged by damp mildew and nutrient degradation; and the amount of wheat bran containing nitrogen in the formula is too small, and there is no adverse reaction in the early stage of mycelial growth, but it can not meet the requirements in the long mushroom stage; ② medium rancidity; water evaporation in ③ bag, mycelium dehydration. These belong to congenital malnutrition, so the mushroom cover is thin, wavy, or non-covered, yellow and white mutant mushrooms.

The culture material is the medium for the growth and development of the fruiting body of Pleurotus ostreatus, and the substrate is closely related to the number, quality and quality of Pleurotus ostreatus. To produce high-quality mushrooms, it is required to achieve the "four must": ① raw materials must be fresh and mildew-free before sun exposure sterilization; ② formula must be reasonable here to introduce two groups of formulations: cottonseed hull 87%, wheat bran 8%, corn meal 2%, lime powder 3%; sawdust-based formula: broad-leaf trunk sawdust 80%, wheat bran 15%, corn meal 3%, lime powder 2%. Water content is about 60%, pH7~8.5. ③ additives must control the common additives gypsum powder or lime powder, both of which can not only provide calcium, but also play the role of regulating pH. Gypsum powder is calcium sulfate, slightly acidic, used to buffer alkalinity; lime powder is light calcium carbonate, alkaline, used to prevent pH partial acidity. The pH required for the culture medium of Pleurotus ostreatus is 7-8.5, which is partial alkali. Plus bag-making at the end of autumn, the temperature is high, in order to prevent the culture medium from rancidity, it is appropriate to use lime powder. According to green food requirements, additives in the formula must not exceed 5%; ④ fermentation must master the mechanism of fermentation is the use of beneficial microorganisms natural catalytic decomposition medium, so as to improve the physical and chemical properties of the matrix, increase effective nutrients, conducive to mycelium absorption, promote the effective components in the culture material to be transformed into fruiting bodies as much as possible, and help to increase yield. During fermentation, 0.3% starter can be added, and the fermentation time is 7 days. After turning the pile for 3 times, it is transferred to bagging, sterilization, cooling and inoculation.

4. The expected date of delivery is uncertain.

Often because the grower asks the mushroom heart to cut, the mycelium physiology is not mature enters the artificial bud, causes the premature birth deformity.

Pleurotus ostreatus needs to "grow bacteria in a hundred days and show buds in one day". For this reason, it is necessary to master the "three standards" of physiological maturity of mycelia: the cumulative incubation time of ① bacteria for 90 days from the date of inoculation, the thick white color of the mycelium on the surface of ② outer bacterial bags, and the firm and elastic feel of ③ matrix, which indicates that the mycelium is physiologically mature.

5. The technology of promoting bud is not in place.

After physiological maturation, the mycelium needed 0: 13 ℃ low temperature stimulation for 10-15 days, and during this period, the temperature difference stimulation above 10 ℃ for 5-7 days was needed to force the primordium to differentiate into mushroom buds. This is a distinctive feature of Pleurotus ostreatus. Growers often fail to master this unique species, lack of low temperature squatting period, insufficient temperature difference stimulation, and incoordination with the physical and chemical requirements of the reproductive stage, resulting in the inhibition of fruiting body development and deformation. In early December, when some mushroom friends entered the shed to promote buds, in order to keep warm, they ignored ventilation, and there was a serious lack of oxygen in the shed. As a result, they were full of "fist mushrooms" with stalks as long as 20cm and covers clenched. Low temperature, variable temperature buds must achieve "four cooperation": ① opening oxygen to untie the bag, loosen the mouth of the bag and twist, so that a small amount of air into the bag, but do not open the whole mouth of the bag to prevent bacteria from drying; ② scratching bacteria wake up according to * * and Beijing, Hebei and other production areas experience, after opening the bag with a small iron rake to remove the original bacteria block and the surrounding 3.5cm aging skin, but other parts do not scratch. Scratching bacteria is conducive to the early appearance of primordia, and the mushroom point is located in the center; ③ sprays water in the shed space with a sprayer on a dry and wet alternating sunny day, with a relative humidity requirement of 85%; lifting the canopy edge cover film at night to naturally cool down to form dry and wet stimulation; ④ scattering light long mushroom stage, during the day should be the roof grass curtain dilute, spacing 6~10cm, let the sun into. The suitable light intensity is 500~600Lx, but direct light should be avoided so as to avoid water evaporation, primordium shrinkage or mushroom body cracking.

6. Sparse bud did not attract attention.

Some people are overjoyed to see the mushroom buds are overjoyed, knowing that the mushroom buds are too dense, but are reluctant to take them off. Due to the neglect of sparse buds and the emergence of mushrooms crowded with each other, there are butterfly-shaped, laterally long ox tongue-shaped, hunchback mushrooms and other variant forms.

Bud thinning can ensure the shape and quality of products, which is one of the important technical links of cultivation management. Specific "four requirements": ① leaves an appropriate amount of buds in each bag, not more than 3 at most. More dispersed nutrition, mushroom body is not thick, but the quality decline; ② bud selection accurate to white color, mushroom body correct as the standard, select the good to bad, stay big to small, stay strong to weak, sparse sparse; ③ careful operation with a sharp knife to cut off the excess young buds, can not hurt the retained mushroom body and hyphae; after ④ thinning, the bag mouth film should be straightened, slightly twisted, heat preservation and moisturizing. The temperature is kept at 13: 18 ℃, not less than 8 ℃, no more than 20 ℃; the relative humidity of the space is 85% 90%. The working path between the bacterial walls has shallow water storage and moisturizing, and the vents should be opened to keep the air in the shed fresh; at the same time, light should be drawn to increase temperature and promote the development of mushroom buds.

7. Poor management during the growing mushroom period

After the mushroom bud appears, it gradually differentiates into a fruiting body. During the period of growing mushroom, it is often due to poor regulation of temperature, light and gas, resulting in abnormal development of the mushroom body, long side, or hunchback, or sunken cover, or spotted pockmarked face, discoloration, and harvest expiration, the mushroom body is too large, does not meet the grade.

During the period of mushroom production, it is necessary to do a good job in the management of "three coordination": the growing period of ① heating and oxygen preservation is in the northerly wind of December and the climate is cold, and the optimum temperature for mushroom production is 13: 18 ℃. In the northern producing areas, in addition to daytime light and heat preservation, burning outside the greenhouse and steam heating can be adopted at night. However, it should be noted that ventilation should not be ignored to avoid hypoxia, resulting in deformation of the mushroom body; ② humidification and ventilation coordinate the space relative humidity requirements of 85% to 95% during the long mushroom period, dry in cold winter, and need to spray water to humidify the space; at the same time, combined with ventilation, do not spray closed water or excessive water, so as to avoid anoxia in the shed, or water dripping on the mushroom surface causes the cover water to concave into a pockmarked face. The coordination of ③ light introduction and moisturizing requires scattered light 500~600Lx in the mushroom period. The 6~10cm needs to be pulled apart between the grass curtains on the roof to let the sun shine into the shed to create an environment of "three points of yang and seven points of yin". But do not light too strong, so as not to cause water evaporation, mushroom body cracking flowers. Therefore, on a sunny day, the working path between the fungus walls in the shed should be kept shallow to store water, so that after the light enters the shed, the water vapor rises and increases the humidity of the space; it can be sprayed to the space in the morning and evening, but it must not be sprayed on the fruiting body, so as not to cause rotten mushrooms or mushroom covers to turn yellow.