I. Use of herbicides in soybean fields In recent years, due to the rapid development of the domestic herbicide industry, the use of herbicides in soybean fields has increased significantly. In 2003, a total of 36 herbicide single-agent active ingredients were registered in soybean fields, see attached table. It increased by 5 species from 31 species in 2001, an increase of 16.1%. The added varieties are: eluthiacet-methyl, pendimethalin, oxyfluorfen, oxaloin, diquat. Except for methyl oxazinate, the other four are domestically available varieties, which only increase the range of use of soybean crops. Among the herbicide single-agents used in soybean fields, they are classified according to their chemical structures, and are used in a variety of phenoxys, amides, diphenyl ethers, and organic heterocyclics. The varieties with large amount and large area are: (fine) quizalofop, acetochlor, imidazolidinic acid (Pushite), flufenazone (Huwei), chlorsulfuron (Zhuwei), enephidine ( Take the net), metolachlor (Dur), oxalox (Gengmeng), propisochlor (Pulebao), bentazone (Bendazone) and so on. According to the control of weed control, there are 14 varieties mainly controlling broadleaf weeds, accounting for 38.9% of the total, and 15 varieties mainly controlling grass weeds, accounting for 41.7% of the total, grass weeds. There are 7 varieties that can be prevented by broadleaf weeds, accounting for 19.4% of the total. According to the application period, there were 17 varieties in the pre-emergence and post-emergence pre-emergence and post-emergence applications, accounting for 47.2% of the total, and 19 varieties after the post-emergence application, accounting for 52.8% of the total. Soybean planting area in China only accounts for 6.1% of the main crop planting area, but the soybean field herbicides are relatively well-equipped. During different application periods, there are some good varieties for different control objects.
The compound herbicides registered in the soybean field are counted according to the compounded active ingredients, up to more than 50 kinds, excluding the varieties with the same active ingredients and different ratios. Compared with 25 varieties of compounding agents in 2000, it has increased by 25 and doubled. Among them, 11 kinds of 3 yuan compounding agents accounted for 22% of the total number of compounding agents. In the compounding agent, it is mainly acetochlor series, quizalofop series, imidazolidinic acid series, propisochlor series, and flufenazone series, and the formula number accounts for 32%, 22%, 14% of the total formula, respectively. , 10%, 10%.
Second, the key technology of soybean field removal 1. Determine the principle of using herbicides in soybean fields There are many herbicides available in soybean fields. Safe, effective and economical are important principles for selecting herbicides. When choosing to use the variety, it is the first place for the crop to be safe and not easy to produce. The second is to consider the control effect on weeds, that is, the control effect is better. Under the condition of good control effect, choose the drug cost as much as possible. Low variety. Weeds in soybean fields include grass weeds and broadleaf weeds. Grass weeds mainly include: crabgrass, marmot, goosegrass, and foxtail. Broad-leaved weeds mainly include Amaranthus retroflexus, Xanthium, Iron amaranth, Sausage, and Purslane. According to the type of weed growth in soybean fields, the varieties used by herbicides should be determined. For example, weeds can be used for pre-emergence soil sealing with acetochlor, metolachlor and propisochlor. Fine quizalofop, fluvofloxacin, and high-efficiency flupirtine for post-emergence stem and leaf spray. For example, if the soybean field is dominated by broad-leaved weeds, the pre-emergence soil sealing can be carried out with flufensulfuron; and the post-emergence stem and leaf spray can also be carried out with fomesafen and acesulfame. Soybean fields mixed with grass weeds and broadleaf weeds should be selected as a single agent with a broad spectrum of herbicides or a single agent with different herbicidal spectrums to achieve the combination of grass weeds and broadleaf weeds.
Determine the amount of herbicide used. Different herbicide varieties have different amounts of weed control in soybean fields. The amount of alachlor is relatively high. In the northeast spring soybean production area, the effective amount per hectare is 2520~2880g, while the effective amount of chlorsulfuron-methyl per hectare is only 15~22.5g, which is 128~168 times. The same herbicide variety is also used depending on the size of the weed, the method of application, the application environment (such as soil texture, organic matter content, soil moisture, temperature, and the use of additives). Under normal circumstances, the weeds are older and the application rate should be increased appropriately. When the agent can be used for both soil treatment and stem and leaf treatment, the amount of soil used for treatment is higher than that of stems and leaves. The herbicide used as soil treatment should be appropriately increased when the soil texture is heavy, the organic matter content is high, and the soil moisture is low; when the stem and leaf treatment agent is used as the stem and leaf spray, when the climate is dry and the soil moisture is low, The dosage should be increased as appropriate. The amount of additives used can also be appropriately reduced. In short, the determination of the amount of herbicide is one of the main factors related to the effectiveness of the control. If the dosage is too low, the control effect is poor. However, if the dosage is too high, it will cause waste, and it may cause phytotoxicity to crops and increase the environment. Pollution.
2. Master the correct application technology and improve the control effect The correctness of the application technology is not only related to the quality of the drug, but also to the safety of the soybean. The relevant application techniques are as follows: 1 Master the correct application time. The application time of herbicides is roughly divided into two types. One is pre-emergence, pre-emergence and post-emergence (referring to weeds 1~2 leaf stage). During the process of sprouting weed seeds, the herbicides are absorbed by the weed roots, cotyledons and the buds of grass weeds, causing weed poisoning to die. Soil treatment agents are often applied during this period, such as trifluralin, chlorpyrifos, alachlor, acetochlor, chlorsulfuron, clomazone, and imidazolium. The second is the application of post-emergence, that is, the application of weeds in the 3~5 leaf stage. Generally, it is a stem and leaf treatment agent, such as bentazone, quizalofop, and dilute. Under normal circumstances, the stem and leaf treatment agent can not be used to spray the soil surface before and after the seedling, and the soil treatment agent can not be used for the post-emergence stem and leaf spray. In the production practice, the soil treatment agent is often applied too late in the post-emergence period, and the application is only after the weed 3 leaf stage, and the resistance of the weeds increases, resulting in poor control effect.
The soil moisture after application is related to the efficacy of the drug, and the control effect is good when the soil moisture is high. In the soybean producing areas of North China, Northwest China, and Northeast China, due to the lack of rain when the soybeans are planted, the soil is dry, and the effects of some fields are not fully exerted, and the fields that have been applied to the medicine are still overgrown. Therefore, in the case of drought, it should be timely irrigated after rain application or medicine. In the absence of irrigation conditions and no rain, the amount of herbicide should be increased appropriately, and the soil should be mixed with the medicine to reduce the volatilization and photolysis of the medicament.
The situation of soil preparation and straw treatment before sowing is another important factor in the efficacy of the disease. In the wheat-bean rotation area, when the wheat is harvested, the soybeans should be harvested as low as possible. The wheat straw scattered in the field should be collected as much as possible, transported out of the field, and then the land is planted and applied. If the wheat bran is too high or the wheat straw is scattered on the surface, the herbicide is sprayed on the wheat straw, and the soil is not sprayed, which can not play a good soil sealing effect and reduce the control effect. When the soil is prepared, the soil should be flat and the clams should be small. When applied, the agent can be evenly distributed on the soil surface to form a tight drug sealing layer. There are many sputum sputum blocks. When applying the medicinal materials, the medicinal materials are not applied inside the sputum. When the sputum blocks are scattered, the weed seeds in the sputum can still sprout seedlings and reduce the control effect.
3. Prevention and control of refractory weeds Due to the different resistance of weeds to herbicides, in the fields that have been continuously removed for many years, the density of some weed populations with weak drug resistance is reduced, while some drug resistance is difficult to treat. Weed population density increased. Such as the spring soybean production area of ​​the yarrow grass, the summer soybean production area of ​​iron leeks. Soybean fields were promoted with less tillage and cultivation, and no ploughing was carried out. The density of perennial weeds and chicory, which are dominated by underground stems, also increased significantly. The damage of the dodder in the rainy summer soybean producing area is also heavier.
The herbicide formula for controlling the control of comfrey, thorn, and leeks is: 148% of oxalox chinensis 1000ml/hm2+25% sulfamethoxazole 1000ml/hm2; 248% dioxin 1000ml/hm2+ 48% bentazone 1500ml/hm2. In the refractory weeds 3~5 leaf stage soybean true leaves to the first compound leaf stage spraying, the yarrow grass must be sprayed before the 3 leaf stage. Add 1% vegetable oil spray aid to the diluent to improve control. Spraying with a good performance spray instrument and using a slit nozzle to achieve even spray. For the fields with many perennial weeds such as thorny vegetables and chicory, it is necessary to change the no-tillage to ploughing before planting, and turn the underground stems of perennial weeds into the lower part of the tillage layer to reduce the amount of excavation and suppress weeds. occur.
Cuscuta is a parasitic weed, the leaves are degraded, and the stems are entangled on the soybean plants, which produce suction cups to absorb nutrients, so that the soybean plants are yellow and less pods or non-pod. The removal of dodder can be carried out after land preparation, using 48% zhongdingling (dimylamine) EC3750~4500ml/hm2 to spray 300~450 liters/hm2 of water, then shallow mixing soil 3~5cm and then planting soybeans. In the early stage of the soybean growth period, the prevention and control method of the dodder was: a survey was conducted in the field, and the marker was found after the onset of the dodder, and then the disease center was sprayed with a 1:400-fold dilution of 10% glyphosate. Due to the different resistance of soybean plants and dodder to glyphosate, dodders began to wilting 4 days after the drug, and a large number of deaths occurred 15 days after the drug. Soybean plants only have yellow leaves, which can be re-greened in the future, with a yield of about 70%, and more than 80% control effect on dodder. Since the dodder is constantly occurring in the field, it must be treated once every 15 days or so.
The control method of the iron leeks is: in the 3~4 leaf stage of the leeks, 80% of the DF60g per hectare, or 24% of the gram of EC300~450ml, spray 300~450 liters of water, or sow in soybean After the emergence of the seedlings, 70% of oxazolone (Sike) WP600~750g is sprayed on 300~450 liters of water per hectare, and the soil with less than 2% soil organic matter cannot use oxazin. You can also use Ma Keer when using Ke Kuang Le to prevent iron leeks.
4. Disable or limit the use of long-lasting herbicides to prevent phytotoxicity to the squat crops.
The herbicide that produces phytotoxicity to the sorghum crop is called long-lasting herbicide. The herbicide has the advantages of good herbicidal effect, wide herbicidal spectrum, less dosage, convenient use, low cost of medicine, and its disadvantage is in the soil. The residual time is long, and it is easy to cause phytotoxicity to the later crops in the farmland, resulting in reduced production and even production. The types of long-lasting herbicides used in soybean fields in China are: imidazolium (Push), flufenazone (Huwei), chlorsulfuron (Zhuwei), dysentidone (Guangling), and methoxy Grass tobacco (golden beans), oxasulfuron (wide grass clear), oxazinone (Sike). The annual use of soybean fields in the country is 6,547 tons, with an area of ​​7.136 million hectares (including a small amount of corn and alfalfa area). Among the above seven long-lasting herbicides, chlorsulfuron-methyl and imidazolium were used in the largest area, reaching 2.5 and 2 million hectares respectively. Soybean fields use long-lasting herbicides to cause serious phytotoxicity to the lower sorghum crops. For example, in areas where “drought-to-water†is implemented in the northeast, the soybean fields are replanted into rice, and the peas rice that has been used with chlorsulfuron-methyl and imidazolium is seriously damaged. Absolutely produced. Beets are sensitive to chlorsulfuron, imidazolium, and imazamox. After 3 to 4 years of application in soybean fields, the sugar beet is still phytotoxic, which has caused the reduction of sugar beet planting area. The use of long-lasting herbicides in soybean fields has a great impact on the growth of post-crop crops. In order to reduce and eliminate such effects and hazards, the following measures should be taken: 1 The safety of soybeans is poor, the application conditions are strict, and For phytotoxicity, long-lasting herbicides with alternative products should be eliminated. 2 The soybeans have good safety and good efficacy. At present, the long-lasting herbicides without substitute products should be determined by the pesticide testing institute and the plant protection department according to the specific conditions of crop summer crops and crop rotation. Imidazoic acid, clomazone, etc. should be mixed with other herbicides to reduce the amount. 3 Strengthen pesticide management and use long-lasting herbicides according to law. Pesticide manufacturers should carefully carry out the registration test of long-lasting herbicides, and clearly identify the areas used, crop crops, and methods of use. The label and instruction manual should be specified to specify the time interval between planting sensitive crops. Users should use long-lasting herbicides as required, and record the land technical files. The distributor recommends that the user should bear the financial compensation for the damage caused by the long-lasting herbicide. 4 Strengthen the training of chemical weeding techniques for farmers, agricultural science and technology workers, and herbicide distributors, and teach knowledge and technology to farmers.
Schedule:
No. Chinese Common Name Product Name No. Chinese Common Name Product Name No. Chinese Common Name Product Name
1 urinary chlorophyll kekelele 13 chlorsulfuron-methyl Bean Wei 25 oxaloin
2 (精精) oxazoline herbaceous weiba 14 thifensulfuron baobao 26 dysentery pine chlorpyrifos
3 (fine) quizalofop-ethyl (fine) grasses 15 oxasulfuron-methyl broadleaf clear 27 quetiapine ester spray
4 (fine) pirfenoxacilin (fine) stabilized to kill 16 acifluorfen weeds 28 imidazolium nicotinate
5 high-efficiency flupirtine high-efficiency grass cover 17 flufenacetate tiger Wei 29 imidazoquinoic acid imazaquin
6 alachlor pull cable 18 acesulfame ketoate 30 methoxyacetice tobacco
7 acetochlor, henas 19 oxyfluorfen, fruit 31, killing grass, destroying grass
8 Isopropyl amide Pulebao 20 扑è‰å‡€ 刈è‰ä½³ 32 olefinic pyridine
9 metolachlor dil 21 oxazinone syke 33 propargyl flufenamide
10 dimethyl pentoline Shi Tianbu 22 Diquat grass fast settling valley 34 fluceic acid
11 Trifluralin Solanine 23 Herneone Reuters 35 Pilarone Quickly
12 仲ä¸çµ åœ°åœ°èƒºè‰ 24 ç›–è‰è‰è‰è‰æ¾ Benzasone 36 oxazinamide
Soybean field herbicide use variety and elimination technology
Soybean is an important food crop and oil crop in China, and it is also an important export agricultural product in China. In 2001, the planting area was 9,482,200 hectares. In recent years, the area of ​​soybean fields has been relatively stable, but the use of single-agent and compounding agents has increased, and the elimination technology has been further improved. The elimination of supporting technologies has become more perfect, which has greatly increased the farmers’ production and income. The role.
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