our company has ran Mineral Products Trading many years,we have close relationship with them,The relationship between mankind and chemical industry is very close, universal access to all aspects of life. In modern life, chemical products can not be obtained almost anytime, anywhere. From the material life such as clothing, food, shelter and transportation to the spiritual life such as culture and art, entertainment and so on, all require chemical products to serve them. Some chemical products play an epoch-making role in the history of human development. Their production and application even represent a certain historical stage of human civilization. As a category of knowledge, chemical industry has many kinds of decomposition or comprehensive classification methods in different historical periods and under different demands. According to the source of raw materials, product classification, but also in accordance with the law of history, history classification. Each division method is difficult to strictly adapt.
Among them, the oil refining industry is to create a higher output value of the industrial sector is the country's important economic lifeline. Natural gas is often symbiotic with petroleum and natural gas chemical industry is often attributed to petrochemical industry. At this stage, oil refining and petrochemicals are the main fuel chemical industry. Products produced by the fuel and chemical industries include fuels and chemical raw materials, which are mainly organic chemical raw materials (except for the syngas used in the production of inorganic chemicals such as synthetic ammonia). Therefore, the petrochemical industry is also a major part of the basic organic chemical industry.
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I. Pathogens and Pathogenesis The root-knot nematode is a colorless, transparent and indivisible invertebrate, male and female, larvae are slender worm-like, male adults linear, slightly rounded tail, colorless and transparent, size ( 1.0-1.5 mmX (0.03-0.04) mm female adult pear-shaped, each female can lay eggs 300-800 eggs, eggs produced in the tail of the glial ovary secreted. The female adults are buried in the host tissue, and the size is (0.44-0.59)mmX (0.26-0.81) mm. The suitable development temperature is 28-30°C, which is higher than 40°C. Less than 5°C is rarely active, and 55°C is 10 min. The deaths are mainly distributed in the 0-25cm soil layer of the soil to distribute most in the 3-10cm soil layers, often leaving eggs or 2nd instar larvae in the soil for wintering. Diseased plants, germs, and irrigation water are the main factors. way for spreading. Soil moisture in the field is an important condition affecting hatching. In general, the temperature and humidity of the protected area is suitable for vegetable growth, and is also suitable for root-knot nematode activity, which is conducive to disease. In addition, the incidence of planting disease is heavy. Nematodes generally survive in the soil for 1-3 years. To appropriate environmental conditions, females buried in the host's roots produce single-celled eggs. The eggs form a first-instar larvae after a few hours of production. The 2nd-instar larvae are hatched and the 2nd-instar larvae leaving the egg masses are in the soil. The intergranular water flow, looking for the root tip of the crop, invaded from above the root cap and settled in the growth cone, its secretion stimulates the expansion of the ductal cells, which results in the formation of giant cell worms, ie root knots. In the growing season, several generations of root-knot nematode proliferate in logarithmic fashion and grow to copulation at the fourth instar. Eggs hatch in the roots and then leave the egg masses at the second instar and enter the soil for further infection or overwintering.
Second, the symptoms of root-knot nematodes mainly damage the roots of plants, root damage, the lateral roots or fibrous roots of plants, the formation of root knots, began as the size of the needle, after the proliferation of enlargement, multiple root knots are connected knotted, chicken claws or Beaded, rough surface and sometimes cracked, white to yellow-white root knot perishable. Roots were dissected and the diseased tissue was a small milky white nematode. The symptoms of the above-ground surface symptoms are different due to the degree of morbidity. The symptoms of mildly ill strains are not obvious. The severely ill strains are stunted, the plants are short, yellow, and wilting in the early days. They are easily mistaken for wilt disease, affect fruiting, and have more fruit. For malformation, when the disease is severe, the whole plant will die. Watermelon and melon emerge 5 to 7 days, and white round root knots can be formed on the root. If the root knot density is too high, and water shortage at the seedling stage, acute seedling death can be caused. The melons can be repeatedly infested during the reproductive period.
III. Comprehensive prevention and control of agriculture
1. Use soil-free seedlings. The use of worm-free soil seedlings or treatment of soil with pre-planting agents to cultivate disease-free seedlings and prevent planting seedlings is an important measure to prevent nematode damage.
2. Deeply turn the soil. In view of the fact that nematodes are distributed in the soil within 5 to 10 degrees of the ground, the use of deep-turning soil layers of more than 25 to turn most nematodes to deep layers can effectively reduce the disease.
3. Remove the sick body. Thoroughly remove the diseased body before harvesting, excavate all the fibrous roots buried in the soil layer, or bury it deeply or burn it. It is an effective way to reduce it.
4. Soilless cultivation is an important agricultural measure that can effectively prevent root-knot nematodes, usually using a mixture of peat, vermiculite, perlite, and coconut shells, and domestically available commercial substrates. Soilless cultivation usually requires supporting drip irrigation equipment and requires good soilless cultivation techniques. After soilless cultivation for 1 to 3 years (years), the matrix needs to be replaced or disinfected, and a large number of substrates will cause new environmental problems. Disinfecting the used matrix is ​​an effective measure. The usual method is to use steam sterilization or soil disinfectant.
5. Rotation: Severely affected fields can be used in rotation with anti-nematode vegetables such as onions, garlic, leeks, etc. They have strong resistance to cucumber nematodes. Planting these crops can effectively prevent or reduce the occurrence of nematode diseases and reduce soil The amount of nematode, so as to reduce the harm to the plant.
6. Use of high temperature to kill nematodes: greenhouses can use summer heat during the leisure season, dig trenches and ridges in midsummer, fill the trenches with water, and then cover the plastic film to close the greenhouse so that the soil temperature within 30 centimeters reaches 50°C. For 15 to 20 days, nematodes are killed under high temperature anaerobic flood conditions.
IV. Pharmaceutical Control Currently, there are many agents for the control of root knot nematodes on the market, but most of them are highly toxic and highly toxic products, and do not meet the national requirements for the production of pollution-free agricultural products. In addition, these products may cause serious poisoning in the soil and crop residues and should not be used. Furthermore, these products have been used for many years to produce resistance and the control effect on nematodes is very low. Here I would like to recommend two methods of pharmaceutical control:
1. Soil line scattered: This product was produced by Hainan Lizhi Bioengineering Co., Ltd. and was awarded the third prize for scientific and technological progress by the Hainan Provincial Department of Agriculture. It is also the only one in the agricultural field and is a national patent product. The active ingredient of this product is 0.5% avermectin GR, supplemented by a sustained-release agent imported from the United States, which makes it possible to slowly release once-administered pesticides that can control juveniles and nematodes in the entire growth period, and are completely controlled. Easy to use, the amount of mu is: 3-5 kilograms of light land mass, 5-7 kilograms of serious land, can be applied to ditch, acupuncture points can be applied, if the applicator to achieve a higher control effect can increase the dose.
2. Abamectin EC + Le Siben EC: Mixing and diluting 300-400 times with two agents is also effective for root control. In general, the nematode within 20 cm can be killed and it can effectively prevent and control underground pests. The advantage of this method is that it has quick results. The disadvantage is that it has a short effective period and it needs to be filled 3-4 times a season.
In contrast, I propose to use the soil to prevent root knot nematodes because of its long-lasting, time-saving features.
This volume seeks to reduce unnecessary crossings, a comprehensive classification of methods designed from the raw materials of fuel chemical branches; from the product of inorganic chemicals, basic organic chemicals, polymer chemicals, fine chemicals and other branches; from the common The branch of chemical engineering proceeding from the regularity of the process, and the comprehensive branch proceeding from historical development and horizontal linkages. Fuel chemical raw materials are oil, natural gas, coal and oil shale and other combustible minerals, so it is divided into petroleum refining industry, petrochemical, natural gas chemical, coal chemical and shale oil industry.
--- talk about one of the root-knot nematode soil diseases: Henan Agricultural University, Wang Hongbin root knot nematode in recent years is an important crop root diseases. This disease has occurred in greenhouses, greenhouses, and open fields and other cultivated crops, generally causing crops to reduce production by 20% to 30%, and severely by more than 50%. Root knot nematode diseases mainly damage eggplants, melons, and kidney beans. Celery, peanuts, soybeans, tobacco, sweet potatoes and more than 20 kinds of vegetables and other crops. Nematodes belong to the invertebrate linear gut nematode class. The nematode body is very small and it is hard to see with the naked eye. The female adults have a round pear shape. The eggs are produced in the glial oocysts secreted from the tail, and the eggs are oval in shape. There are 100 to 300 eggs in one oocyst. The 1st instar larvae hatched in the eggs, shelled and then emerged as 2nd instar larvae, and peeled 3 times as adults. Plant parasitic nematodes in soil are one of the major pathogens of plant infestation diseases, but they are more active than fungi, bacteria, viruses and other pathogens and penetrate into the host with acupuncture needles. In the sandy soil and continuous plots, it is more prone to disaster.