Corn is one of the largest varieties in China, and it is the main food crop in China. However, corn has encountered more and more complicated weed damage during the planting process. The author hereby writes for discussion.

I. Types and succession of weeds in corn fields

The main weeds in corn fields include alfalfa, crabgrass, foxtail, golden foxtail, wild pheasant, comfrey, willow locust, sorrel, stalk, stalk, scorpion, scorpion, scorpion, scorpion, water prickly Needles, wolves, grass, nightshade, ramie, iron leeks, cocklebur, thorns, thorns, thorns, leeks, artemisia, reeds, fragrant aconite and so on.

Weed community with the extension of the use of herbicides, the number of weeds decreased, and the number of refractory weeds increased, such as comfrey, nightshade, thorny vegetables, big thorns, sage, chicory, stalk Flowers, ramie, Xanthium, fragrant aconite, etc.

Second, the current corn weeding problem

1. The phytotoxicity is common

The use of herbicides in corn is generally affected by factors such as premature and low temperature sowing, or the use of technical irregularities, or residual phytotoxicity.

(1) Before the residual phytotoxicity, the use of herbicides such as oxacillin, flufenazone and quinclorac is easy to cause damage to the cockroaches.

(2) Maize field herbicide phytotoxicity The common pesticides with poor safety of corn pre-emergence herbicides are acetochlor, 2,4-D, 2A4, oxazinone, etc.; Acetochlor + oxazinone, dripazine · B (acetochlor + oxazinone + 2,4-butyl butyl ester), B · bis (acetochlor + 2,4-butyl butyl ester + Flushing grass and so on.

(3) Other pesticides and phytotoxics Some coating agents can also cause common phytotoxicity, such as the use of artificially grown plant growth regulators such as naphthaleneacetic acid, indolebutyric acid, sodium nitrophenolate, paclobutrazol, etc. Such substances as fungicides such as paclobutrazol, imazalil, triazole alcohol, propiconazole, triazolone, chloropyrimidinol, ethiazole, benzyl triazole alcohol, diniconol, etc., at low temperatures or dosage When too much, it is easy to cause phytotoxicity.

2. Analysis of herbicide efficacy or phytotoxicity factors

(1) Neglecting traditional agronomic measures to effectively control weeds relies too much on chemical weeding. It is considered that herbicides are versatile. The use of weeding is the only herbicide-free measure, blindly pursuing herbicidal effects and abusing herbicides. Regardless of crop safety and environmental pollution, increase the amount of herbicide used or increase the number of uses, resulting in a doubling of herbicide use, which is 5-10 times.

(2) Ignoring the mechanical control measures, the machinery deep-deep deep pine, Fuqiu turned over the ground, autumn land preparation, autumn fertilization, autumn application, autumn ridge, spring planting before the sowing, cultivating and cultivating grass and other effective grass control measures were ignored.

(3) Crop varieties are planted in the area, prematurely planted, and the herbicides and seed coatings are added.

(4) The structure of herbicides is unreasonable. Most farmers choose herbicides mainly after seedlings. Due to weather factors, plant protection machinery quality and use technology, the drug efficacy is poor and the drug damage is heavy.

(5) Plant protection machinery standards are low and the use of technology is not standardized

a. The quality of plant protection machinery is poor, the standard is low, the use of technology is not standardized, and illegal operations are common, resulting in waste of herbicide loss, serious phytotoxicity, and refractory weeds.

b. The plant protection machinery lacks scientific management, the quality certification of plant protection machinery flows in the form, and a large number of imported machinery are idle. Some of the problems encountered by the authors of foreign plant protection machinery companies are poor, the instructions farmers do not understand, or the configuration of key spray parts is unreasonable, sometimes problems can not find the company.

Third, how to use pre-emergence herbicides

1. Adjust the structure of the herbicide

Corn herbicides are mainly pre-emergence herbicides, supplemented by post-emergence herbicides, and should account for more than 85% of pre-emergence plants (including more than 20% in autumn application and 50% to 60% in spring application). Accounted for less than 15%. Promote autumn herbicides. Autumn herbicide is an effective measure to control weeds in the spring of the second year. Compared with spring application, it is safe for corn, which can improve the efficacy of 5%~10%, increase yield by 5%~8%, and apply herbicide before spring maize. Compared with post-emergence application of herbicides to increase yield by 10% to 15%, it is a new technology compatible with soybean ridge cultivation, corn mulching, autumn fertilization and autumn ridge.

2. Choose a safe herbicide

Although the herbicide range between some herbicides is the same or similar, there is a significant difference in the safety of corn. Generally, the herbicides are cheaper and have lower safety, and the herbicides with good safety and wide herbicidal spectrum have higher prices. According to many years of practice, the author divides herbicides into recommended varieties, restricted use varieties, and eliminated varieties. Restricting the variety is a problem with safety, or the residual period is long, and it is necessary to reduce the amount of mixing. Elimination of varieties means poor safety, or long residual time, there are already alternative varieties.

(1) Corn, popcorn cornfield

It is recommended to use a variety of mesotrione, ezetimibe, metolachlor, propisochlor, alachlor, thifensulfuron, and sulffenapyr.

Mixed use: metolachlor (metolachlor, propisochlor, alachlor) + sulffenapyr + thiophenesulfuron, oxasulfuron + sperm metolachlor (or isopropyl Oxalamine, alachlor), should pay attention to the residual problem of oxasulfuron. Thiosulfuron-methyl + metolachlor (or metolachlor, propisochlor), mesotrione + metolachlor (or metolachlor, propisochlor). Atrazine + refined metolachlor (or metolachlor, propisochlor, alachlor), mesotrione + atrazine + thifensulfuron, suitable for soils with soil organic matter below 5% . Metolachlor + oxazinone + thifensulfuron, suitable for soils with more than 2% organic matter.

Restricted use of the species oxazinone, cyanazine, atrazine, dicamba, pendimethalin and the like.

Eliminate (not recommended) varieties of acetochlor, 2,4-D (butyl ester, dimethylamine), 2 methyl 4 chlorine and so on. The mixed preparations include ethylazine (acetochlor + oxazinone), dripazine·ethyl (acetochlor + oxazinone + 2,4-butyl butyl ester), and B. bis (acetochlor +) 2,4-butyl butyl ester + chlorpyrifos).

(2) Sweet corn (糯 corn) field

The recommended species are oxazolone, oxafludone, pendimethalin, flufenacet, alachlor, metolachlor, oxalofen, cyanazine, thifensulfuron, atrazine.

Limit the use of the varieties paraquat and sulforaphane.

It is not recommended to use dipyridamole, clopyralid, flumethacic acid, mesotrione, broadleaf, flusulfuron, dicamba, ligulon, chlorpyrifos, oxazinone, thiophene Amine, acetochlor + safener, isoxaflutole, oxyfluorfen, nicosulfuron.

(3) Corn farming

The use of the species oxaconazole is recommended.

Limit the use of the variety of oxalate.

It is not recommended to use the varieties of pendimethalin, clopyralid, diuron, flufensulfuron, flumethacic acid, flufenacet, alachlor, metolachlor, broadleaf, and fensulfuron Ketone, dicamba, ligulon, thifensulfuron, chloropyrimidene, oxazinone, dimethenamid, acetochlor + safener, isoxaflutole, oxyfluorfen, nicosulfuron .

3. Maize field control refractory weeds recommended herbicide formula

(1) Chicory, thorny vegetables, comfrey

48% sulfometrimine 4~5 g/mu, or 75% thifensulfuron 2~2.5 g/mu.

Mixed use: 48% sulffenapyr 2 g / acre + 75% thifensulfuron 2 g + 38% atrazine 200 ml; or 48% sulffenapyr 2 g / acre + 72% 2, 4-D Isooctyl ester 50 ml +38% atrazine 200 ml.

(2) Aconite

72% metolachlor 200~250 ml/mu, or 48% alachlor 300~500 ml/mu, or 96% sperm metolachlor 180 ml/mu.

(3) Question Jing

Corn seedlings were selected from 72% 2,4-diisooctyl ester 50 ml/mu, or 48% dicamba 30-67 ml/mu, or 70% oxazolone 25-30 g/mu.

Mixed use: 72% 2,4-diisooctyl ester 50 ml / mu + 48% dicamba 30 ml / mu (pre-emergence).

(4) Small root garlic (è–¤ (xie) white)

Corn seedlings were selected from 72% 2,4-diisooctyl ester 50 ml/mu, or 38% atrazine 200-300 ml/mu + 2,4-diisooctyl ester 50 ml.

(5) Wrinkle sorrel

Before the corn seedlings, 2,4-diisooctyl ester 40 ml/mu, or 75% thifensulfuron 2 g/mu was used.

(6) Xanthium

50% propargylflufenamide 6~8g/mu, or 80% sulffenazone 3g/mu, or 75% thifensulfuron 2g/mu, or 10% mesotrione 100~170ml/ mu. Mixed use: 10% mesotrione 100 ~ 170 ml / acre + 38% atrazine 170 ~ 200 ml.

After corn seedlings, 4% nicosulfuron 67 ml/mu, or 45% valerian 133-200 g/mu, or 22.5% bromoxynil 100-120 ml/mu, or 10% mesotrione 100~ 130 ml/mu, or 33.6% oxacillin 15 ml/mu, or 48% bentazone 70-100 ml/mu, or 70% oxazolone 30 g/mu.

4. Innovation Theory - Weeds should talk about controlling hazards

(1) Weeds can't be eliminated

According to the study of the United States and the former Soviet Union, there are more than 50,000 weed seeds in the soil layer of 30cm/m3. In the same land, various methods (agronomy, machinery, chemistry, ecology, etc.) are used to kill grass. After 20 years The plough weeds are only reduced by 50%, and in the natural state, they quickly recover to more than 50,000 seeds. No matter how much it costs people to eliminate weeds, weeds can't be eliminated. Each herbicide has a limited spectrum of herbicides, such as only 120 species of the herbicide herbicide glyphosate, and nearly 1,000 species of farmland weed species, resulting in 20~30 species of major weed species in various crops. .

(2) Control weed damage, coexistence of crops and weeds

The new theory is to control weed damage rather than eliminate weeds. Farmland weeds are symbiotic with crops and make an important contribution to maintaining agricultural ecological balance.

Farmland weeds are defined as long-distorted plants, which are called weeds, which are medicinal materials, or cash crops, or pastures, or vegetables. For example, soybeans are corn, self-generated soybeans are weeds in corn fields, corn is soybeans, and self-generated corn is also weeds. Under natural ecological conditions, there is no concept of weeds, and humans grow crops in order to obtain high yields and benefits. Adopt agronomic, chemical, mechanical and other measures to control the weed damage within the allowable threshold of economic, ecological and social effects.

We must change our mindset, overcome the ignorant science and human selfishness, and learn to live in harmony with weeds.

(3) Changing the evaluation method of herbicide effects

There are three traditional evaluation methods. One is to calculate the weed control effect by the percentage of weeds. The number of weeds after treatment is 95.1%~100% effective, 90.1%~95% is better, 80.1%~90% is A certain effect, 80%~70% is poor, and 70% or less is invalid. The second is to calculate the control effect of fresh residue of weeds, the standard is the same as above. The third type is the visual method, and the control effect is calculated based on the weed coverage rate. The first is commonly used, the second is used in the middle and late stages of weeds, and the third requires a certain level of experience and a high level of skill, which is rarely used. According to the production practice, the second evaluation method is more scientific, the weed fresh weight is reduced by more than 80%, and the impact on crop yield is less than 5%, or even no effect. It is recommended to determine the new weed control effect evaluation method based on weed fresh weight loss rate and formulate new weeding effect grading standards.

5. Determine the dosage according to soil texture and organic matter

In medium organic soils with a content of 2.5% to 5%, the herbicide is mainly affected by the clay particles, and the clay particles are increased, and the dosage is also increased accordingly.

When the soil organic matter content is less than 2.5% or at 5% to 10%, the herbicide dosage is directly affected by the soil organic matter content.

When the soil organic matter content exceeds 12%~15%, a variety of herbicides are strongly adsorbed by soil organic matter.

Therefore, the herbicide dosage should be increased or decreased according to the soil organic matter and clay particle content.

The application data of pre-emergence herbicides should indicate the application amount of clay soil, loam soil and sandy soil below 3% of soil organic matter, and more than 3% or 4%~5% or 4%~8% of soil organic matter. The amount of medicine used in soil, loamy soil and sandy soil.

6. Soil pH and dosage

The pH value of the soil is also an influential factor to be noted. When the pH value is low, the efficacy is lowered. For example, when the pH value is <5.5, the efficacy of the dysentery, atrazine, and imidazolium nicotinic acid is lowered.

When the pH value is <5, the effects of simazine, oxazinone, cyanazine and the like are lowered.

When the pH value is >7, the efficacy of simazine, oxazinone, cyanazine, and atrazine is increased, and the oxazin can also increase the phytotoxicity of soybean. The simazine and atrazine can also increase the residual risk of diarrhea. crop.

7. How to use pre-emergence herbicides under drought conditions?

(1) Adopting mixed soil application

It is best to have 15~20mm of rainfall after application in the pre-emergence. The herbicide is leached down to the germination part of 0~5cm weeds with rainwater, and the weeds are exposed to the herbicide. In the northern part of China, the spring application period often encounters strong winds and droughts, and the herbicides before the seedlings are easily scraped off by the wind or stay on the surface of the soil. They cannot contact the weeds of the weeds, and it is difficult to exert the herbicidal effect. Or irrigation conditions, using mechanical mixed soil application to ensure stable drug efficacy.

(2) Mixing soil before or after sowing in autumn or spring

1 The whole site should be leveled and applied before the application of the ground should be level, soil, no plant residues and large clods on the surface. The plots with many perennial weeds must be deep-rooted. It is not allowed to replace the soil before application.

2 Spraying Before adjusting the spray evenly, the sprayer is an important part of the uniform spraying of the herbicide. In the spray operation, standard operation must be adhered to avoid leakage.

3 Mix the soil thoroughly by using double-row disc harrow or rotary tiller and other mixed soil. After application, smash the ground in time, the depth is 10~15cm (the herbicide is 5~7cm), cross over the ground, and the speed is above 6km/h. After the application of the drug, ridges and pressures are maintained in time. If the ridge is not applied after application, the depth is 6~8cm. The time required for sputum application after application: the thiocarbamate is violent, and the volatility is strong. It must be immersed in the soil within 15~20 minutes after soy application; the dinitroaniline flurazepam , Zhong Dingling, etc. in the 1-2 hours after the application of soybeans before sowing, the ground should not exceed 8 hours at the latest; the requirements for herbicides such as amides, triazines and sulfonamides are not strict.

(3) Application of pre-emergence mixed soil application after sowing

1 After sowing, the ridges and shallow-mixed herbicides in the pre-emergence planting ridges and ridges are applied to the shallow mixed soil for 2~3cm, which can improve the efficacy and stabilize the herbicidal effect under drought conditions. The soil mixing machine can be used for cultivating machines, rotating hoes, and the like. After the ridge sowing soybean application, the mechanical soil can be used for about 2cm, and the pressure can be suppressed in time to prevent the wind from scraping off the soil and the medicament together.

2 After sowing, the seedlings were planted in the pre-emergence and mixed with the soil. After sowing, the soil was ploughed and rotated in a timely manner. The depth of the soil was 2~3cm, and the speed was 6km/h.

3 After sowing, the cultivating and cultivating of northern soybeans, corn and other cultivating crops can be applied and sown after ridge planting, and the soil is cultivated by cultivator 2cm, and then pressed and kept.

Fourth, prevent phytotoxicity

Suitable seeding

Proper planting is the high-yield period of corn planting. Many years of experience, the local average daily temperature is stable at 13 ° C, as the starting temperature of sowing, is an important measure to avoid phytotoxicity (coating agents, herbicides), low temperature, and strong seedlings. According to the routine selection of planting varieties, a temperate zone is retreated. For example, the high-yield period of corn planting in Heilongjiang Province is generally from May 15 to 25; the daily average temperature of Daxinganling Land Reclamation Bureau (Dayangshu) is stable at 10 °C, the traditional calculation method is the growth period. 110 to 125 days, through two years of practice, play an important role in breeding seedlings, controlling late disease, and promoting precocity.

2. Prevention of phytotoxicity

Corn seed dressing per 100 kg of grass (4% chitosan-nitrogen agent) 100 ml + Yi protection (gibberellin + brassinoin) 200 ml (can be mixed with seed coating agent, or mixed with seed coating agent People can mix and protect + grass, or can replace the seed coating agent, the seed coating can only be used for 15 to 20 days, to delay the infection and reduce the harm). The seed dressing mainly solves the phytotoxicity of the seed coating agent and the residual phytotoxicity of the herbicide, and can also play the role of resisting cold damage, resisting drought, promoting seedling growth and resisting root diseases.

V. Give full play to mechanical weeding measures

1. Mechanical cultivating is very important

Medium-cultivation and soil-cultivation is the main method of weeding widely used in various parts of China. It can eliminate a large number of inter-row weeds and eliminate some weeds between plants.

The first cultivating in the corn arch soil period for deep pine and shallow cultivating, can bury the germinated and newly unearthed annual weeds, and has a significant control effect under the conditions of suitable soil moisture and loose texture; using pre-emergence herbicides After cultivating, it can increase the efficacy of the drug, and also has the effect of warming and releasing cold and promoting emergence.

The second cultivating should be carried out in the 3~4 leaf stage of the corn, preferably 2 days after the corn seedling herbicide.

The third cultivating in the 5~6 leaf stage of maize, before the germination of soil pathogens, can significantly reduce the occurrence of late large spot disease, small spot disease, stem rot and other diseases, which is conducive to the control of late weeds.

The fourth cultivating was carried out before the ridge was closed.

The traditional habit of controlling weeds in the northern alpine region has 3 shovel and 4 shovel. The post-cultivation of corn seedlings is beneficial to the efficacy of post-emergence herbicides, which is beneficial to the control of weeds in the later period, promotes the growth of maize roots, and has anti-barching, drought-resistance and anti-caries functions. .

The summer crops in North China are hot and rainy. The key to controlling summer weeds is to control the weeds in the germination and seedling stages by combining the intercropping seedlings for 2~3 times.

Deep plowing

Deep ploughing is an effective measure to prevent weeds such as stalks, chicory, thorns, stalks, reeds, lobster, alkali grass, stalks, stalks, sage, and diarrhea.

(1) Fuqiu deep turn, autumn preparation

It adopts mechanically loosening, alternating shallow and shallow farming practices, and a three-year rotation cycle. Futian high temperature weather deepens the ground, the perennial underground rhizome is cut and chopped, accompanied by high temperature and sun exposure, the perennial rhizome can die 70%, the remaining rhizome is cut, and the regenerated seedlings are well controlled. There are still weeds sprouting after the volts turn, and some can also mature the seeds. Therefore, the sloping ground should be sown before the weeds mature to prevent the grass seeds from multiplying.

Deep turning is faster and better for controlling annual weeds. At the same time, it promotes microbial activity by deep ploughing, fixes nitrogen in the air, and increases soil nutrition.

The temperature of turning over the ground in autumn is low, especially when the northern crops are closed and the time is turned over. After turning over the ground, it is followed by the depression. The ridges are to be fertilized in autumn and the ridges in autumn are not as good as the control effect of perennial.

(2) Spring plowing

Spring ploughing can effectively eliminate weeds in winter weeds and weeds in early spring. The depth of spring ploughing should be shallower. Pay attention to the fact that in dry areas and when soil moisture is low, it is not suitable for spring ploughing and turning over the land, which is easy to run, affecting seed germination and emergence.

3. Weed control in early spring and inoculation

The main tasks of spring land preparation are to increase warming, induce weeds, arrange sowing and control weeds in stages; use the differences in grass conditions and seedlings to adjust the contradiction between farm time and strength, and ensure the control of weeds in the later stage.

Rotary tillage

Rotary tillage is a kind of farming operation for cutting, crushing and stirring the topsoil of the plough layer. It is suitable for the cultivation of paddy fields and dry fields. After the crops are harvested, the vegetative and reproductive organs of weed plants and perennial weeds can be controlled and completed through one operation. Plowing, hoeing, leveling, pressing. Rotary tillage should be carried out on plots with deep tillage and few weeds. The operation period is mainly based on rotary tillage in autumn, and the crops are operated in time after harvest. In the spring, the rotary tillage pays attention to the protection, and the rotary tillage-seeding-squeezing continuously works. The depth of autumn rotary tillage is 12~15 cm, and the depth of spring rotary tillage is 8~10 cm. After rotary tillage, the soil in the plough layer is finely divided and the ground is flat. The maximum size of the clods per square meter of ploughed layer is 3-6 cm.

5. Depression and suppression

Depression and repression are often combined with other soil cultivation practices to induce weed seed germination and excavation in order to take other measures to control it.

Sixth, plant protection machinery should be standard, use technology should be standardized

The use of standard plant protection machinery is the basic requirement for spraying herbicides. The non-standard performance is poor in the preparation of key components, the spray is not standard, the pressure is insufficient or too large, the leakage is dripping, the speed is too fast, and the final spraying is uneven, heavy spray or leakage. Severe spray, causing grass shortage or phytotoxicity.

Vigorously popularize the technical specifications for the use of plant protection machinery. The use of plant protection machinery is an agronomic measure. Every agricultural technician and boom sprayer operator should master the training of agricultural technology and operators on plant protection machinery standards and technical specifications.

The use of plant protection machinery is not adjusted and operated according to the specifications, resulting in heavy drug damage and poor efficacy. The evaluation criteria are as follows:

1. Using spray droplet size and density as evaluation criteria

Spraying the post-emergence herbicide spray droplet diameter 250~400μm, spraying the systemic pesticide droplet density 30~40/cm2, spraying the contact pesticide droplet density 50~70/cm2; spraying the pre-emergence herbicide spray droplet The diameter is 300~400μm, and the droplet density is 30~40/cm2.

2. Using the amount of liquid spray as the evaluation standard

The pre-emergence herbicide is sprayed. The spray volume of the manual knapsack sprayer is 225~300L/hm2, and the spray volume of the sprayer sprayer is 180~200L/hm2.

Manual knapsack sprayer should use fan-shaped nozzles, such as imported 11002 or 11003 fan nozzles, with 50 mesh column anti-drip filters, spray pressure 2 atmospheres, spray volume 225~300L/hm2, one spray at the time of application Ridge, do not spray the spray left and right, and the height of the nozzle and the ground, the spray pressure should be stable, and the walking speed should be uniform to ensure uniform spray.

Suspension and traction type sprayer sprayers use fan-shaped nozzles, such as imported 11003, 11004 fan nozzles, 50-column column anti-drip filter, spray pressure 3 atmospheres, spray volume 180~200L/hm2 spray bar from the ground The height is 50cm, and the speed is 6~8km/hm2 when applying. Large horsepower self-propelled sprayer sprayer uses fan-shaped nozzles, such as imported 11006, 11008 fan nozzles, with 50 mesh column anti-drip filters, spray pressure 4~5 atmospheres, spray volume 180~200L/hm2, Shi The speed of the medicine is 10~18km/hm2.

The atomizer nozzle or fan-shaped nozzle is used for the aircraft spray, and the spray volume is 30~50L/hm2.

3. Plant protection machinery quality standards and technical specifications reference

For the quality standards and technical specifications of plant protection machinery, please refer to "Safe and Efficient Use of Herbicides" by Wang Xianfeng (Chemical Industry Press, 2016).

More pesticide knowledge , please pay attention to China Pesticide Network

The mine monitoring, monitoring, and control network under the unified management of the mine`s comprehensive automation system is the platform, which integrates the video stream, data stream, and information stream of the monitoring points of the various branch systems above and below the mine. It is not compatible with the existing information platform and other subsystems of the mining area. Seam connection to realize the scientific informationization of data collection, production scheduling, operation management, decision-making and command of the whole mine, to ensure the safety and efficiency of mine production, and to improve the level of enterprise productivity.

Coal Mine Automation Unattended

Coal Network Switch,Mine Management System,Dc Stabilized For Mine,Mine Intrinsically Safe Alarm

Jinzhou Jinshi Mining Equipment Technology Co., Ltd. , https://www.jsminingeqpt.com