What are the precautions for cultivating straw mushrooms in summer?
Straw mushroom, also known as orchid mushroom and button-foot mushroom, originated in Nanhua Temple in Shaoguan, Guangdong. China began artificial cultivation 300 years ago, and it was introduced to countries around the world by overseas Chinese in about the 1930s of this century. It is an important tropical and subtropical mushroom and the third largest cultivated edible fungus in the world. China's straw mushroom output ranks first in the world, mainly distributed in South China. Straw mushroom is rich in nutrition and delicious in taste. Every 100g of fresh mushroom contains 207.7mg vitamin C, 2.6g sugar, 2.68g crude protein, 2.24g fat, and 0.91g ash. Straw mushroom protein contains 18 kinds of amino acids, of which essential amino acids account for 40.47-44.47%. In addition, it also contains various mineral elements such as phosphorus, potassium, and calcium. Straw mushroom is named because it often grows in moist and rotting rice straw, and is mostly produced in Guangdong and Guangxi, Fujian, Jiangxi, and Taiwan, China. It is plump, thick-fleshed, short-stemmed, smooth, and extremely delicious, so it is called "orchid mushroom" and "delicious wrapped-foot mushroom".
Historical records prove that straw mushroom originated in China and has a history of more than 300 years. In the second year of Daoguang (1822), Ruan Yuan and others compiled the "Guangdong Tongzhi Tuchan Pian" according to the "Zhouche Wenjian Lu": “Nanhua mushroom: Southerners call fungi xun, and Yuzhang and Lingnan also call them gu. Those produced in Caoxi Nanhua Temple are called Nanhua mushrooms, also domestic xun. Their taste is not inferior to northern mushrooms.” In the twenty-third year of Daoguang (1843), Huang Peirong compiled the "Yingde County Annals Wuchan Lue", which also has the same record: “Nanhua mushroom: originally from Qujiang Nanhua Temple, the local people imitated it, and the taste is also not inferior to northern mushrooms.” According to Fujian's "Ningde County Annals": “In the north of the city, in the urn kiln, the grain was rotten, and after rain mushrooms grew, like stars clustering and bursting forth together; farmers gathered them and threw them on the market.” It can be seen that straw mushroom was originally a wild edible fungus growing on rotting rice straw in the south, and was first picked and eaten by the monks of Nanhua Temple.
Precautions for summer cultivation of straw mushroom
1. Prevent insufficient nutrition
Nutrition is the material basis for the growth and development of straw mushroom and an important condition for high yield and good quality. The nutrition of straw mushroom mainly includes nitrogen sources, carbohydrates, minerals, and physiologically active substances. In a mushroom bed or straw pile with sufficient nutrition, the mycelium grows vigorously, the fruiting bodies are plump, the mushroom production period is long, and both yield and quality are relatively good. Therefore, when cultivating straw mushroom, high-quality, golden-yellow rice straw should be selected; moldy and deteriorated rice straw should not be used, and some organic matter such as soybean straw and dried powder of chicken, duck, pig, and cattle manure should be added to the rice straw pile to supplement nitrogen sources, which is beneficial to high yield and good quality.
2. Prevent insufficient moisture
Water is not only an important component of straw mushroom, but also all nutrients can only be absorbed and utilized by the mycelium after being dissolved in water. The metabolic products of straw mushroom also need to be dissolved in water before they can be excreted from the body. Insufficient water will hinder the growth and development of straw mushroom, and even cause it to dry up and die. However, if there is too much water, it will affect the aeration of the culture material, inhibit the respiration process, and lead to a large number of deaths of mycelium and mushroom buds. Practice has proved that the water content in the substrate or rice straw is about 65%, suitable for the growth and development of straw mushroom mycelium. The relative humidity of the air around the mushroom bed is 85%-90%, most suitable for the growth of straw mushroom fruiting bodies.
3. Prevent sunlight exposure
The spore germination and mycelial growth of straw mushroom generally do not need sunlight, but the formation of fruiting bodies does need sunlight. Under completely dark conditions, it is very difficult to form fruiting bodies. Diffused light can promote the formation of fruiting bodies, promote their robust growth, increase resistance to diseases and insects, promote the transformation and accumulation of pigments, and make the color of fruiting bodies darker. However, strong direct light has an inhibitory effect on fruiting bodies. Therefore, open-field cultivation of straw mushroom must be covered with straw mulch, and the site should preferably be selected under sparse tree shade where “three parts sunlight and seven parts shade” can be reached by sunlight.
4. Prevent unsuitable temperature
Straw mushroom originated in the tropics and subtropics. It is a high-temperature agaric. The temperature range for mycelial growth is 20°C-40°C, and the optimum temperature is about 32°C.
The optimum air temperature for fruiting body growth is 30°C-32°C. The temperature in the straw pile is 35°C-38°C, most suitable for fruiting body development. Therefore, when the mycelium or fruiting body is below or above its temperature range during growth, effective measures should be taken immediately to restore it to the normal growth temperature.
5. Prevent too rapid air flow
Straw mushroom is an aerobic saprophytic fungus. Sufficient oxygen is an important condition for the normal growth and development of straw mushroom. If oxygen is insufficient and carbon dioxide accumulates too much, mushroom buds often stop growing or die because respiration is inhibited; but if the ventilation is too large, water disperses too quickly, which is also unfavorable to the growth of straw mushroom. Therefore, it is best to choose a place with slow air convection for cultivating straw mushroom.
6. Prevent pH imbalance
pH is an important factor affecting the growth and development of straw mushroom. Practice has proved that the optimum pH for the growth and development of straw mushroom mycelium is 7.2-7.5, the optimum pH for fruiting body formation and growth is about 7.4, and the optimum pH for spore germination is 7.4-7.6. If the pH is too high or too low, it will affect the normal growth and development of straw mushroom.