Technology of sericulture in greenhouse

Sericulture in greenhouse is a new technology in sericulture production, which has been popularized and applied in Shandong and Jiangsu for more than 10 years. The experimental breeding carried out in Tongxiang, Xiuzhou, Huzhou, Deqing, Shangyu and other cities and counties in our province has achieved initial success. All the techniques of sericulture in greenhouse have been gradually popularized.

Main advantages of sericulture in greenhouse

First, it is easy to build a shed, which is conducive to large-scale operation. The construction of the greenhouse can make use of the land edge of the field and the open land of the house, which can solve the contradiction of insufficient area for sericulture.

Second, less investment and high economic benefits. In general, a mulberry garden with 5 mu of mulberry can build a greenhouse of 200mur300 square meters, which can raise 7 silkworm eggs at a time, with an investment of more than 6000 yuan, while the simple greenhouse only needs about 2000 yuan. In winter, greenhouse can be used to grow vegetables, edible fungi or raise chickens to increase income.

Third, labor saving and high efficiency. Sericulture in greenhouse carries out co-rearing of small silkworms, mulberry rearing of large silkworms, and automatic rearing. According to the survey, a conventional sericulture can only raise about 5-year-old silkworms, while 3 can be raised in the greenhouse, which greatly improves the work efficiency. Fourth, the separation of human and silkworms to meet the requirements of improving the quality of life of farmers, but also the modernization of villages and towns.

Types and main characteristics of large shed

At present, according to the structure, sericulture greenhouses in our province are mainly divided into simple silkworm rooms, greenhouses and mobile silkworm rooms, and there are also pit rearing in Shengzhou.

1. The size of the simple silkworm room is generally 35 meters × 8 meters, the surrounding wall is cement brick, the top is asbestos tile, build two-story silkworm platform, the cost is about 35 yuan / square meter. The main features are that the utility model has the advantages of long use time, convenient operation of sericulture, easy control of temperature and humidity and small temperature difference. However, the one-time investment is large, so it can only be combined with aquaculture in comprehensive utilization.

2. According to the material and structure of the greenhouse, the greenhouse can be subdivided into three types: plastic greenhouse, straw greenhouse and simple greenhouse.

① plastic greenhouse size according to the site and feeding volume, generally 20 Mel 25 m × 7 Mel 8 m, using prefabricated galvanized thin-walled greenhouse steel pipe with a diameter of about 22 mm as arch, 0.1mm thick plastic film as roof covering material, and then covered with 1 Mel 2 layers of sunshade net as heat insulation layer. Generally build two-story silkworm platform, the cost is about 30 yuan / square meter. The main characteristics are that the cost is low and it is convenient for comprehensive utilization, but the performance of high temperature protection is poor and the temperature difference between day and night is large.

② straw greenhouse is used to raise silkworms in places where ducks are concentrated. The size is generally 12 meters × 8 meters × 6 meters, surrounded by 1.2 meters high brick walls, build two silkworm platforms, rural construction of about 20 yuan / square meters. The main characteristics are that the material is easy to be obtained, the cost is low, the effect of preventing high temperature is better, and the temperature is less affected by the outside world, but the disinfection is difficult to be thorough, the straw is used for a short time, and it needs to be replaced once in 3-4 years.

③ simple greenhouse makes use of the open space in front and back of the house, according to the site and feeding quantity, use wood or bamboo to build temporary scaffolding according to the house wall, then cover it with woven cloth, and dismantle it after the silkworm period is over. The main feature is that it is convenient to build and put into the province, but the temperature is obviously affected by the outside world and the temperature difference is large.

3. The size of the mobile silkworm chamber is 8.1 m × 7.2 m × 3.8 m, surrounded by expanded perlite plates, with angle iron as a flat beam, covered with asbestos tiles, and a two-story silkworm platform with a cost of about 120 yuan / square meter. The main feature is that it is easy to disassemble and flexible in size, but the cost is high.

4. The pit is dug in a high-lying rice field with a size of 13 meters × 1.3 meters × 2 meters. Bamboo slices are used as scaffolding and covered with straw. Generally, two silkworm eggs can be raised in each pit. The main feature is that it is convenient to dig holes, low cost, but inconvenient to operate.

Practical techniques of sericulture in greenhouse

The main results are as follows: 1. the choice of shed site is flat, the drainage is smooth, far away from rice fields, vegetable fields and orchards, and build a greenhouse closer to the mulberry garden.

2. Keep the shed dry when entering the shed, uncover the film in the new greenhouse during the day and cover the film at night to avoid dampness in the shed. Before releasing silkworms, spread a layer of film on the ground, then spread a layer of straw on the film, and put the silkworms on the straw. 1-3-year-old co-breeding, 4-year-old 4th day or 5-year-old 2nd day can enter the shed.

3. The temperature of the temperature regulating greenhouse is generally higher than that of the indoor silkworm room, and the temperature difference between day and night is larger. The key point of greenhouse temperature regulation is to strengthen ventilation on the basis of cooling.

The high temperature can be alleviated by the following measures

① covers the sunshade roof covers the sunshade, which is beneficial to reduce the temperature in the shed. The commonly used shading objects are sunshade net and grass curtain. The cooling effect of two layers of sunshade net covered by the roof is better than the first layer, the inner layer is close to the plastic film, the outer layer is about 15ml 20cm away from the roof, and hangs out about 1.5m on both sides of the greenhouse, forming an outer corridor, which is more beneficial to prevent direct sunlight on both sides. According to the investigation, this method can reduce the temperature in the shed by 3mur4 ℃. If the roof is covered with grass curtain, it should not be too thick to reduce the weight of the roof on rainy days. In addition, planting vines around the greenhouse and using green sunshade can effectively reduce the temperature in the greenhouse.

② roof spray water during the period of high temperature, from 9: 00 a. M., spray water every 1 hour to about 3: 00 p. M. According to the investigation, spraying water on the roof can reduce the temperature in the shed by 1 ℃ 2 min.

③ strengthen ventilation after sunrise on sunny days, open the film on both sides of the greenhouse for ventilation, and put down the film on both sides to keep warm in the evening when the temperature in the shed drops below the suitable temperature for feeding. When the temperature is high, ventilate day and night. Put down the sunshade net on both sides of the greenhouse on rainy days and lift the film on both sides of the greenhouse to facilitate ventilation.

④ is suitable for feeding wet leaf shed with high temperature and easy to cause mulberry leaf withering after ventilation. Wet leaves can be fed at noon on a sunny day, and 0.3% available chlorine concentration bleaching powder solution is sprayed in the air to replenish moisture and prevent disease.

4. Mulberry breeding in greenhouse emphasizes ventilation, and leaf cultivation is easy to cause mulberry leaves to be withered, so mulberry breeding is suitable. After silkworms enter the shed and give mulberry leaves for the second time, mulberry can be reared. Give Sang three times a day. The amount of mulberry should be given to sufficient mulberry leaves in advance according to the characteristics of high temperature and rapid development in the greenhouse. When there is about 10% residual mulberry, give the next mulberry. However, the amount and times of mulberry should be reasonably adjusted according to the development and weather changes of silkworms.

5. Disease prevention and damage prevention should be done well before sericulture is disinfected according to conventional methods. For continuous use in the greenhouse, about 10 cm of topsoil should be removed before using chemicals. After disinfection, before sericulture, sprinkle a layer of chlordane powder on the ground, and then sprinkle a layer of fresh lime powder. Sprinkle more dry materials during the silkworm period. In rainy and muggy weather, fresh lime powder was used in the morning and evening to disinfect silkworm pedestal. If you enter the shed at the age of 4, you should remove the silkworm sand and clean the silkworm seat in time after feeding at the age of 5.

6. the temperature in the shed is high at the right time, and the silkworms will mature quickly, so the preparation work should be done in advance. One day before ripening, the leaves were fed, and the silkworm seat was filled with short straw, and the silkworm fly body was sprayed once at the same time. Start releasing silkworms when you see about 5% ripe. Sprinkle 1 layer of fresh lime powder before placing silkworm eggs and feed the leaves once more. We should pay attention to avoid overcooked cocoon, otherwise, it will cause a large number of cooked silkworms to camp cocoons in the silkworm seat and suffer losses; we should also pay attention to shading to avoid excessive light and increase the loss of cocoons in silkworm seats.

Main techniques of sericulture in greenhouse

The technology of sericulture in greenhouse is different from that of conventional indoor rearing due to the change of environment. On the basis of conventional indoor rearing techniques, the following technical measures should be grasped: strict disinfection and disease prevention, and fresh lime should be sprinkled once a day after entering the shed to keep silkworm seats dry and do a good job of killing flies at the same time. When moving silkworms, sprinkle a layer of fresh lime on the ground, spread a layer of straw or a layer of film, and put the silkworms with the same degree of development together for future management, and the density of silkworm heads should be sparse. When entering the shed at the right time, the young silkworms are generally co-reared at the age of 1-3, and the 4th or 5th instar enters the shed on the 2nd day. If they eat, they will enter the shed. Because the poor resistance of silkworms to the environment will affect the physique of silkworms, those who enter the shed at the 4th instar can also be reared on the silkworm platform or in the silkworm plaque. Temperature and humidity control, the focus of temperature regulation of sericulture in the greenhouse is to strengthen ventilation and ventilation, cover the sunshade net, skillfully eat wet leaves, use the roof to cool down, and drain moisture in the rainy season; flexibly give mulberry, the amount of mulberry can be appropriately reduced for a short interval during the day, and a long interval at night can be appropriately increased, so that silkworms can fully eat well; shading on clusters and shading of cooked silkworms should be paid attention to to prevent the occurrence of non-cocooning.

Sericulture in greenhouse is an important technical measure to promote the scale operation of sericulture and realize the modernization of sericulture. It can be said that it is a relatively mature technology in Shandong and Jiangsu, but our province is just in its infancy and lacks mature and complete technical experience. Therefore, when applying the technology of sericulture in greenhouse, all localities should grasp it flexibly according to the local actual situation.