Causes of death in volvariella volvacea cultivation and preventive measures

Straw mushroom, also known as orchid mushroom and bract mushroom, originated from Nanhua Temple in Shaoguan, Guangdong Province. It was artificially cultivated in China 300 years ago and was introduced into the world by overseas Chinese in the 1930s. It is an important tropical and subtropical mushroom. It is the third largest cultivated edible fungus in the world. The output of straw mushroom in China ranks first in the world, mainly distributed in South China. Straw mushroom is nutritious and delicious. Each 100g fresh mushroom contains 207.7mg vitamin C, 2.6 g sugar, 2.68 g crude protein, 2.24 g fat and 0.91 g ash. Volvariella volvacea protein contains 18 kinds of amino acids, of which essential amino acids account for 40.47-44.47%. In addition, it also contains a variety of mineral elements such as phosphorus, potassium, calcium and so on.

Environmental requirements of volvariella volvacea

Temperature: volvariella volvacea is a high-temperature fungus, the growth and development temperature is 10-44 ℃, the temperature requirements vary with varieties and growth and development periods. Basidiospores: the germination rate is the highest when the germination temperature is 30-40 ℃, the germination rate is the highest when the germination temperature is 40 ℃, the second is 35 ℃, the lowest is below 30 ℃, and the germination rate is higher than 45 ℃ or less than 25 ℃. Mycelial growth: the mycelium could grow at 10-44 ℃, but grew slowly when it was lower than 20 ℃, grew very little at 15 ℃, almost stopped growing at 10 ℃, and died when it was below 5 ℃ or above 45 ℃. Fruiting body development: the fruiting body development temperature is 24-33 ℃, and 28-32 ℃ is the most suitable. It is difficult to form fruiting body when it is lower than 20 ℃ or higher than 35 ℃.

Moisture: straw mushroom is suitable to grow under the condition of high humidity, the water content of culture material is about 70%, and the air relative humidity is 90-95%. When the air humidity is less than 80%, the fruiting body grows slowly, the surface is rough and dull, and when it is higher than 96%, the mushroom body is prone to necrosis and disease.

Light: straw mushroom vegetative growth stage of light requirements are not strict, in the absence of light conditions can be normal growth, into the reproductive growth stage need light induction in order to produce fruit bodies. But avoid strong light, suitable for light 50-100lx. The color of fruiting body is related to the intensity of light. Straw mushroom is dark and shiny in strong light, and dim or even white in weak light.

Nutrients: studies have shown that glucose, fructose, sucrose, peptone, asparagine and glutamine are good carbon and nitrogen sources of volvariella volvacea, while rice straw, waste cotton and bagasse are the main materials for cultivating straw mushroom. The analysis shows that asparagine and glutamine are rich in waste cotton, and their contents account for 1% of the total amino acids. It can be seen that waste cotton is an ideal material for cultivating straw mushroom. However, the nitrogen content of waste cotton varies from 0.25 to 1.45%, while the nitrogen content of volvariella volvacea culture material is 0.6-1%. Supplementation of soybean flour can increase yield.

PH: the pH of volvariella volvacea was between 4-10.3, the germination rate of basidiospore was the highest when pH 7.5, and pH 4.7-6.5and 8 were suitable for mycelium and fruiting body stage.

Causes of death in volvariella volvacea cultivation and preventive measures

In the production process of volvariella volvacea, pieces of small mushrooms are often seen wilting and dying, resulting in economic losses. The causes and preventive measures of dead mushrooms are summarized as follows.

1. Poor ventilation

Volvariella volvacea is a high-temperature aerobic fungus, which needs enough oxygen for its growth and development. In the process of cultivation, in order to improve the stack temperature, sometimes the film covering time is too long, so that too much carbon dioxide in the stack leads to hypoxia, and mushrooms wilt because of poor ventilation, poor exhaust and difficult to grow up normally. Within 4 days of sowing 1Mel, we should pay attention to ventilation for half an hour every day. With the increase of the amount of mycelium and the emergence of needle mushrooms, we should appropriately increase the amount of ventilation.

Second, lack of moisture

The growth of volvariella volvacea needs a lot of water, if there is not enough water during sowing or not replenishing water in time after picking mushrooms, and the grass is too thin and has poor moisturizing performance, it will lead to the wilting of mushrooms. After sowing, before the mycelium grows to form needle mushrooms, if you feel that the water is not enough, you can replenish the heavy water; after the head tide mushroom is over, the grass should be sprayed with water to prevent the evaporation of water in the material.

3. Sudden changes in temperature

The mycelial growth and fruiting body development of volvariella volvacea have different requirements for temperature. Generally, the temperature of mushroom setting is about 30 ℃. However, the continuous high temperature in the midsummer season will lead to the death of mushrooms in batches. Therefore, the hot summer to choose a cool site for heap cultivation, the material is covered with grass quilt and spray more water, the top of the pile should be shaded by a shed.

Fourth, the environment is sour

The mycelium of volvariella volvacea is suitable to grow in alkaline environment. Although the pH is below pH 6, it can form buds, but it is difficult to grow into mushroom. After picking the first tide mushroom, 1% lime water or 5% plant ash water can be sprayed to keep the pH of the pile about pH8. Fifth, the water temperature is uncomfortable.

Volvariella volvacea has certain requirements on water temperature, such as spraying well water for about 20 ℃ or surface water directly irradiated by sunlight for more than 40 ℃, all the mushrooms will wilt and die the next day. Water spraying should be carried out in the morning and evening, and the water temperature should be about 30 ℃.

6. Infect miscellaneous bacteria and cause insect pests

Using moldy straw and other raw materials as culture materials, cultivated in unclean sites, will lead to a large number of pests, especially when straw mushrooms are cultivated in cottonseed shell, the hyphae in the materials will disappear quickly after the occurrence of mites, resulting in the death of all young mushrooms on the bed. Adding 3% tea seed cake powder or 0.2% trichlorfon solution to the haystack can have the effect of pest control. Straw mushroom is very sensitive to pesticides, when mushroom buds appear, do not use pesticides.