The fields under the hot sun are busy with agriculture. There are some unusual people in the industrious farming team: they are plainly dressed, sweating, and sometimes wiping the insect traps in their hands to observe carefully; sometimes peeling the ears of seedlings and staring closely. They are the scientific researchers who are active in the front line of agricultural pest control. They have been working hard all the year round to establish a resource-saving and environment-friendly biological control system with Chinese characteristics.
Ecological pest control
Ecological management of pests and diseases is one of the development trends of world agriculture. Starting from the integrity of the ecosystem, biological control and ecological control are used to reduce and suppress pests and diseases. This method of preventing diseases and insect pests through nature for agriculture is of great significance to the construction of ecological civilization:
Reduce governance costs, improve the quality of agricultural products, maintain ecological stability, avoid polluting the environment and destroying biodiversity, so that agricultural and forestry production and environmental protection are not delayed.
China attaches great importance to the green prevention and control of agriculture. In the “National Quality Strategy for Promoting Agriculture (2018-2022)” jointly issued by seven departments including the Ministry of Agriculture and Rural Affairs, clearly put forward the action of implementing green prevention and control instead of chemical prevention and control, and build 300 green prevention and control demonstration counties, and the green prevention and control coverage rate of major crops will reach more than 50%. The Regulations on the Prevention and Control of Crop Diseases and Insect Pests effective from May 1 this year also clears that priority is given to encouraging and supporting green prevention and control technologies such as ecological governance, popularizing the application of information technology and biotechnology, and promoting the intelligentization, specialization, and greening of prevention and control work.
In recent years, Chinese researchers have taken root in the field and explored a series of effective methods for green prevention and control. For example, the frequent occurrence of green land pests in central city of Dongying City, Shandong Province. Among them, the borer pests (such as longicorn, carpenter moth) and some underground pests (such as grub), etc., make the management of this park a headache. From 2018 to 2019, the Dongying City Garden Bureau introduced Dastarcus helophoroides, Scleroderma guani, Steinernema feltiae Agriotos and other natural enemies and biological agents in various parks and lakes in the city, using the parasitic relationship between organisms to prevent and control longicorn and carpenter moth and other pests. The experiments yielded surprising results.
Controlling pests with bacteria
Soybean is one of the important food crops in China. In order to scientifically and effectively control the occurrence of pests and diseases in the field of corn-soybean intercropping, Professor Yang Wenyu and his team of Sichuan Agricultural University, after 18 years of unremitting efforts, on the basis of the traditional corn-soybean intercropping, innovative supporting technologies such as “reduced amount of integrated fertilization, chemical control and anti-falling, and green prevention and control” have been developed.
“Inhibiting bacteria with bacteria, treating insects with bacteria” is a two-pronged approach. In order to effectively control the frequent pests of corn and soybeans, the team selected beauveria bassiana with broad-spectrum insecticidal properties. The conidia produced by the conidial reproduction of beauveria bassiana are attached to the insect epidermis after contact with the pest. The lipase, proteinase, and chitinase produced at the top of the bud tube germinated by the conidia can dissolve the insect shell and invade the pest body. Growth and reproduction, consumption of nutrients in the insect body, the formation of a large number of mycelium and spores covered the body, the toxins produced can disrupt the metabolism of the pest, and eventually promote its death. Compared with traditional pesticides, this bacteria agent has the characteristics of broad insecticidal spectrum, no resistance, green and no pollution.
Associate Professor Shang Jing, a member of the research team, introduced that after applying the green prevention and control system, the prevention and control rate of pests, diseases and weeds reached over 85%, the pesticide reduction was 25%-40%, and the application of pesticides was reduced by 4-5 times, it took the lead in realizing the three integrations of band-shaped intercropping, the occurrence of harmful organisms, prevention and control strategies and prevention and control technology, which filled the gap of the green integrated prevention and control technology system at home and abroad. According to reports, the yield of corn on the land is at the same level as the original net crop production, and 130-150 kg/mu of intercropping soybeans and 100-130 kg/mu of intercropping soybeans can be added. Compared with net crop corn, this technology can increase farmers’ income per mu by 350-600 yuan.
Use insects to control diseases and insect pests
Every spring, one of the most important pest control problems for farmers is aphids. The accidental killing of pesticides and pesticide residues caused by the prevention and control of pests and diseases has caused many problems such as environmental pollution and food safety.
In the face of this problem, many scientists started to take action. The “ecological pest control” biological prevention and control technology system created by Professor Liu Yusheng, deputy dean of the New Rural Development Research Institute of Shandong Agricultural University, is a typical example of combining green prevention and control theory with practice.
Around 2000, Shandong Agricultural University, where Professor Liu Yusheng is working, has started to study the technology system of harmonia axyridis to control aphids. After 20 years of continuous improvement, the team has successfully established the technical system of harmonia axyridis for ecological production, breeding and control of aphids.
“How to cultivate their natural enemies before the breeding of aphids in early spring, or when the number is scarce, this is the key to winning,” Professor Liu Yusheng said, “The ecological production system of harmonia axyridis to breed and control aphids is divided into two major parts. One is the natural enemy cultivation system. In the winter season, first collect the harmonia axyridis through the artificial trapping technique, and then use sorrel to cultivate the sorrel aphid to breed the overwintering harmonia axyridis, before February-March of the following year, mass reproduction of harmonia axyridis will be realized. The second is the protection system. When early aphids began to breed, the number was limited. At this time, an overwhelming amount of harmonia axyridis could be released to directly control the number of harmful aphids. “
As the subsequent large-scale production of the system studied by Liu Yusheng’s team is improved, it will help the protection of ecological plants and minimize the use of pesticides.
Original Chinese article:
By / Maggie, Liu Xiling (Volunteer)
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