Solution to the focus of cultivation techniques of Pleurotus ostreatus

Pleurotus ostreatus, also known as Pleurotus ostreatus, is a kind of rare mushroom product newly developed in recent years and welcomed by the market at home and abroad, and has become the highlight of popularizing cultivated varieties all over the world. the annual cultivation volume in Gutian County, Fujian Province alone has reached 100 million bags. Due to the short cultivation history of Pleurotus ostreatus, the lack of standardization of production management, and the fact that the mycelium and fruiting body of the mushroom contain almond flavor, there are many diseases and insect pests, resulting in substandard yield, declining quality and excessive agricultural residues of the products. it directly affects the economic benefits and the sustainable development of the industry. With the implementation of the National Law on quality and Safety of Agricultural products and the requirements of the market access system, the requirements for pollution-free products will be more stringent in the future. This paper makes a comprehensive analysis on the focus and problems of the cultivation technology of Pleurotus ostreatus, and puts forward some solving measures for mushroom farmers' reference in production practice.

1 the misunderstanding of culture medium formula affects the substandard yield.

1.1 High yield standard

When the biological characteristics and physiological and ecological conditions of Pleurotus ostreatus meet the requirements, the bioconversion rate can achieve 133%, that is, feeding (dry material) 100kg, fresh mushroom 133kg can be produced. According to the present situation of Gutian mushroom area, the cultivation bag of 15 × 30cm is usually used, each bag contains 300g dry material, and its yield reaches the standard of 400g fresh mushroom is high yield. If it is in accordance with the quality requirements of fresh-keeping mushrooms, it should not be less than 300g. However, many existing growers have failed to meet the standards.

1.2 substandard factors

Although the yield is not up to standard, there are many factors, but one of the most important reasons is the improper preparation of culture medium. Its misunderstandings: first, one-sided emphasis on reducing costs and reducing the amount of wheat bran, some wheat bran accounts for only 10%, and some even only account for 5%; second, the amount of lime is the same in spring, summer, autumn and winter; third, the cooking time of mixing bags is prolonged, the matrix is rancidity, and nutrients are destroyed.

1.3 basic requirements

The whole production cycle of vegetative growth and reproductive growth of Pleurotus ostreatus takes 10 months, which consumes a lot of nutrients. If the nutrition supply can not keep up with and is congenitally insufficient, the high yield cannot be achieved.

1.3.1 the main nutrition in the cultivation of Pleurotus ostreatus with wheat bran and tea is protein in organic matter. The protein content of the existing cultivation raw material cottonseed shell is only 4%, while the protein content of wheat bran is 13.5%, which is more than 3 times that of cottonseed shell; in particular, the amino acid content of wheat bran protein is as high as 46%, which is the main nitrogen source of Pleurotus ostreatus nutrition and the additive of VB1; therefore, wheat bran is an indispensable nutrient in the formula. Its reasonable formula requires that wheat bran accounts for no less than 15% of the total medium.

1.3.2 Lime is used as a buffer of acidity and alkalinity of the culture medium, and calcitonin nutrients are increased at the same time. The general dosage is 2%-3%. The specific dosage should be increased or decreased according to the daily temperature of the ingredients, less when the temperature is below 20 ℃, and more when the temperature is above 28 ℃, in order to control matrix rancidity.

2 pollution and control of miscellaneous bacteria

2.1 causes of pollution

The contamination rate of miscellaneous bacteria in the bag of Pleurotus ostreatus is higher than that of other mushrooms. The main reason is that the cultivation quantity is relatively large, the average grower makes 5000 bags at a time, and the workload is heavy, and the techniques of mixing, bagging, sterilization, inoculation, germ culture and so on are out of control. Especially in the old mushroom area, the pollution bag treatment is not good, the spore index of space miscellaneous bacteria is increasing, and the stress resistance of mixed bacteria is getting stronger and stronger.

2.2 Common miscellaneous bacteria

Mainly Trichoderma viride, Alternaria alternata, Penicillium, Monascus flavus and other competitive miscellaneous bacteria. Especially green Trichoderma, great harm, once contaminated, resulting in bacteria bags scrapped.

2.3 Control measures "7 in place"

2.3.1 cottonseed hulls were fermented by adding water 24 hours in advance.

2.3.2 after adding wheat bran, do not pack the mixture into the oven for more than 6 hours to prevent the matrix from becoming sour.

2.3.3 the sterilization temperature standard lasted for 24 hours after 100 ℃.

2.3.4 the hole in the bag should be prevented during handling.

2.3.5 the inoculation time should be carried out at night on a sunny day and strictly aseptic.

2.3.6 attention should be paid to temperature control, moistureproof, ventilation and protection from light during hairy bacteria culture.

2.3.7 turn over the pile on a regular basis and find that the contamination of miscellaneous bacteria can be dealt with in a timely manner. When mite damage occurs, it can be killed by spraying 73% EC 2000-3000 times.

3 Mushroom mosquito control

3.1 causes and characteristics of insect pests

Due to the unique fragrance of Pleurotus ostreatus hyphae, it will induce a large number of mushroom mosquitoes to invade and gnaw on the hyphae, the hyphae of the injured parts will shrink, and the matrix will become black, moldy and give off a bad smell, affecting the emergence of mushrooms. Mushroom mosquito is the enemy of Pleurotus ostreatus cultivation.

3.2 morphological characteristics of Mushroom mosquito

There are many species of mushroom mosquitoes. At present, the mushroom midge occurred in Gutian tea mushroom belongs to mushroom gall midge. The adult head and chest are black, the wings are transparent, and the belly flowers are white. When the bag opens, it enters the inner surface of the bag to destroy the mycelium growth and lay eggs. The egg is milky white at the initial stage, then turns yellow, and the egg stage is 4-5 days. When the larvae mature, they are like nematodes, with long 2~3mm, small ones as thick as hairs, and large ones close to toothpicks. Each adult can reproduce 8-12 larvae, and the larvae pupate in 10-15 days. The pupa length is 1.3~1.6mm, and the pupa stage is 6-7 days. The generation cycle of sexual reproduction is about 30 days.

3.3 "four keys" of prevention and control measures

3.3.1 purify the environment, improve the hygiene around the mushroom house, and disinfect it with lime.

3.3.2 physical control mushroom doors and windows are equipped with nylon screen to prevent adults from flying into the room to lay eggs.

3.3.3 Chemical control of mushroom room gasification and disinfection with gas mold disinfectant, or spray with 1000 times dilution of 50% phoxim EC

3.3.4 spraying 3-4 days before the opening of the bacterial bag can burn the sanitary pill powder or point mosquito-repellent incense according to the requirements of pollution-free cultivation; pesticides should be selected with broad-spectrum, low toxicity and short residual period varieties, such as Regent, acetamiprid, insecticide, buprofezin or 50% dichlorvos EC. Some mushroom farmers use aluminum phosphide to produce mushrooms 15 days later and grow poorly. This is because aluminum phosphide volatilizes to form poisonous and sour gases after absorbing air and water vapor, and is injured after mycelium contact, and even rotten and mildew, which affects the growth of mushrooms.

When applying medicine, you should "sit in the right seat". Any kind of disease and insect has its symbiotic law, and the control effect can only be achieved by selecting corresponding pesticides and the best control period. When mite damage occurs during the bacterial bag culture period, 73% EC of propargite can be selected and sprayed after 2000-3000 times dilution. The use of any chemical pesticides is prohibited during the growing mushroom period. After cleaning the damaged mushroom body and its material layer, in order to prevent the recurrence of insect pests, biological pesticides and environment-friendly pesticides, such as avermectin (100mL/ bottle) + acetamiprid (275mL/ bottle) + diflubenzuron (350mL/ bottle), can be applied. After mixing these three pesticides with water and 250kg spray, the insecticidal effect is very good, which meets the requirements of pollution-free cultivation.

Highly toxic chemical pesticides such as methamidophos, carbofuran and chlordimeform prohibited by the state shall not be used under any circumstances.

4 newly discovered two kinds of mushroom tube cover diseases and their control

4.1 symptom characteristics

After 2-3 batches of Pleurotus ostreatus harvested, a layer of fungal quilt with yellow or white, smooth and sticky surface often appeared on the surface of the mushroom tube, which became dim in the later stage, and a brown net cover appeared on the surface of the mushroom tube. These two newly discovered quilt diseases can cause the mycelium of Pleurotus ostreatus to blacken, soften and stink, stop growing mushrooms and become waste bags.

4.2 pathogenic bacteria

Of the above two diseases, the former belongs to Cladosporium, the pathogen is Cladosporium grapevines, and the latter is Streptomyces brownii.

4.3 "four gatekeepers" of prevention and control measures

4.3.1 the humidity of the space should not exceed 90% when spraying water.

4.3.2 pay attention to ventilation and ventilation.

4.3.3 when the temperature is high, cover the sunshade and spray water on the roof to cool down.

4.3.4 the isolation pass will remove the bacterial bags that have occurred from other places to prevent the spread of germs.

5 Infectious diseases of fruiting body and its control

5.1 types of diseases

Various infectious diseases such as brown rot, soft rot, quenching, black spot, mildew or air sore often occur in the growth stage of fruiting body, resulting in poor yield and quality of Pleurotus ostreatus.

5.2 symptoms

The above-mentioned infectious mushroom body became brown, shrunk, moldy and rotten, and lost its commercial value.

5.3 "five key points" of prevention and control measures

5.3.1 do a good job in disinfecting mushroom rooms and purifying the environment.

5.3.2 Water should be cleaned during mushroom production, ventilation should be strengthened to avoid high temperature during mushroom growing period.

5.3.3 the injured mushrooms should be removed and burned in time, then cut off the water, increase the ventilation and reduce the humidity in the space.

5.3.4 after harvest, the bacteria bag was sprayed with 50 times solution of streptomycin 1 ∶ to kill the bacteria hidden in the bag and avoid recurrence when the second tide mushroom grew.

5.3.5 mature mushrooms were harvested and processed in advance.