Control Technology: Building a Safe Production Line for Vegetables

Li Wei Topic Description: Study on the sustainable control technology of major pests and diseases of fruit vegetables and cruciferous vegetables in North China Experts: Li Xinghong (Plant Protection and Environmental Protection Research Institute, Beijing Academy of Agriculture and Forestry Sciences) Luo Chen (Department of Plant Protection and Environmental Protection, Beijing Academy of Agriculture and Forestry Sciences)

Our country has a large population and meeting people’s needs for food and vegetables has become the top issue. In order to increase the productivity of land, pesticides and fertilizers are commonly used in China, but excessive use has also caused environmental pollution and endangered food security.

How to find a sustainable control technology for pests and diseases that can both reduce pesticides and protect the environment has become a major issue in China's agricultural research.

To understand the antibiotic resistance of pathogens

China has a vast territory and there are certain differences in pests and diseases in various regions.

The research group monitored the resistance of Botrytis cinerea, Sclerotinia sclerotiorum, and Melon powdery mildew in Beijing. The results showed that the frequencies of the resistant strains of Trichodinone and Carbendazim in the Beijing region were 67.74% and 58.62%, respectively; the resistance of Botrytis cinerea was changed with different years, and the benzimidazole was changed. The resistance to carbamoylimides and the resistance to carbamoyl esters showed a significant decrease in the proportion due to the pathogens such as Botrytis cinerea and benzoimidazole and dicarboximide pesticides. It showed strong resistance and was sensitive to carbamate pesticides. As a result, some farmers frequently applied carbamate pesticides in recent years to increase their drug resistance. However, despite the benzimidazoles, The amount of pesticides used in the formamides decreased, but the susceptibility of the bacteria to benzimidazoles was not restored. Therefore, it has basically lost its control effect.

The research team suggested that benzimidazole pesticides should be abandoned during the prevention and treatment. Because the susceptibility of pathogens to dimethylimide pesticides is also very weak, they can only be used as rotation drugs. Expert Reviews:

In today's world, environmental issues have attracted much attention and chemical pesticides are undoubtedly facing enormous challenges. The research group adopted the demonstration application of the chemical and biological coordinated control technology of melon diseases, that is, the scientific and rational use of chemical pesticides and biological pesticides, and applied the two in a coordinated manner. In this way, only 4 drugs are used in a growing season, and the number of routine use of drugs is reduced. More than half of the chemical pesticides have been reduced by more than 70%, and the cost of prevention and control has also been greatly reduced. The research group carried out demonstration applications on melon and cucumber crops, and the control effect on the two major diseases of melon white powder and downy mildew was between 80% and 90%. The community comparison test and large area were conducted at the special vegetable base along Shunde. Application demonstration shows that the technology product has potential application prospects.

The research group also established the main diseases of tomato gray mold, melon vegetables, and the sustainable treatment technology system and accessory products of eggplant vegetable virus disease, and carried out demonstration and promotion in Tongzhou, Daxing, Hancunhe, Fangyi, Fangshan and other cities. With an area of ​​nearly 30,000 mu, the control effect is over 90%, the use of chemical pesticides is reduced by more than 60%, and the loss of disease is restored by 30% to 40%. The average income per mu increases by about 2,000 yuan, and the output value of high-brightness pepper grows by 10,000 yuan per mu. .

Find out the non-toxic and harmless inducer

In the research of plant disease control, the inducer is a hot spot at home and abroad, but it is mostly limited to theoretical studies and laboratory tests. The research team first conducted a screening study of the inducer, and screened out a plant-derived antiviral agent VA and a chemical inducer C. In addition, through the field application technology research, the assembly and configuration of a comprehensive set of technologies.

Indoor and outdoor experiments showed that plant-derived antiviral agents can induce local induced disease resistance and systemic induced disease resistance of tobacco plants against tobacco mosaic virus, and significantly control field pepper and tomato viral diseases in field applications. The effect of preventing and controlling chili virus disease is over 80%, and the loss of virus disease is reduced by 30% to 40%.

The research team found that chemical inducer C has a broad-spectrum disease-resistance effect and has a controlling effect on bacterial diseases and virus diseases. Indoor artificial inoculation assay showed that the effect of chemical inducer C on the black rot of Chinese cabbage reached 71.24%, and there was no significant difference compared with the preventive effect of neomycin. The chemical inducer C inhibited the infection of tobacco mosaic virus, and the inhibition rate of the stain was 37.34%.

After chemical inducer C was mixed with plant-derived antiviral VA, the effect of VA on disease control could be increased. The inhibition rate was 51.98%, which was significantly higher than that of VA. The same was true for field trials. It was shown that chemical inducer C had a significant synergistic effect on the plant-derived inducer. The control effect of VA+C on pepper virus disease was 63.16%, and the disease reduction rate was 30.82%, which was significantly higher than that of VA. 32.23% The rate of reduction of disease and disease was 22.62%. At the same time, VA+C treatment significantly increased the chlorophyll content in leaves of pepper plants. Expert Reviews:

Through in-depth research and practice, the research team has developed and screened the drug-inducing agents to be non-toxic and harmless, which overcomes the two major drawbacks of chemical pesticides that pollute the environment and are easy to produce drug resistance. In particular, the coordinated application of the two drugs can increase the resistance of plant sources. The effectiveness and stability of the toxicants are of great significance for the further industrialization of the two. In addition, research and development of plant-derived hybrid inducers and field application techniques have been successfully applied in the prevention and control of diseases such as tomato, pepper virus disease, and leaf mold, providing a new approach for the prevention and control of plant diseases.

Study on the biological control of Lysimachia mellifera

In addition to the monitoring of the resistance of pathogens and the development of non-toxic harmless inhibitors, the research team also conducted research on the cold strains and their reproductive applications of the larvae introduced in northern China.

The research team found that the wasp can parasitize the nymphs of all ages of B. tabaci, and can complete the development. However, the parasitism rate and the emergence rate are different due to the different populations of B. cinerea and B. tabaci. Among them, the parasitism rate of nymphs was the highest in 3 years, which was 55.3% in the United Kingdom and 57.6% in the United States. In addition, when nymphs of the nymphalid nematodes parasitize the nymphs at different ages, the time from spawning to adult emergence and the longevity of the adult nymphs differ depending on the population of the nymphs and the age of the parasitoids. For example, when the nymphs were parasitized for 1 year, the developmental duration of the larvae was significantly prolonged. The British population was 24 days and the American population was 23.4 days. The temperature and supplemental nutrition have a greater impact on the lifespan of adult larvae. Without feeding, the larva was the longest life at 23°C and the shortest life at 33°C; however, when it was fed 10% honey water, it had the longest life at 18°C ​​and the shortest life at 33°C. The difference between temperatures was significant. . Feeding mealworms nymphs, the longest life at 18 °C, the shortest life at 33 °C, the temperature difference is also very significant.

The research team also found that the temperature has a regular effect on the developmental history of the larvae. In the range of 18-33°C, the developmental duration of the reptilian wasp shortened as the temperature increased. At 18 °C, the American population required 34.7 days from spawning to adult emergence, and 7.8 days at 33 °C. The temperature difference was significant, and with the increase of temperature, the growth rate accelerated. However, the British population has different stages of development at different temperatures and the same conditions as the American population. At 18°C, the British population needs 36.1 days from the egg development to the adult and 8.4 days at 33°C, which is shorter than the former. About 3/4 of the time, the effects of different temperatures on the developmental period were significantly different. In addition, the low temperature not only prolonged the developmental duration of the larvae of the larva, but also caused the adult eclosion to be uneven. Expert Reviews:

In 2004, the research team demonstrated the greenhouse vegetables in Tongzhou District and the tomato vegetables in greenhouses. The comprehensive production and protection control of Bemisia tabaci was carried out, and the control effect was significant. In the strict management of greenhouses, the removal of field weeds and old dead leaves, colonization of clean seedlings, the use of hanging yellow plates and the release of natural enemies measures to improve the control effect and reduce the use of pesticides, promote the application of 10 Shed room, control effect reached more than 70%. In 2005, the Ligusticum wasp was released at the Mentougou Biyu Vegetable Production Base, Xiedao, Jushan Farm, and Yanqing Fuzhi Vegetable Production Base. The average control effect reached about 75%.