All the cornfield herbicide mixture formulas are right here, worth saving

Many farmers are not very familiar with herbicides specifically designed for corn fields, and some do not even know what products are available. This article compiles the corn field herbicide formulas on the market. All the corn field herbicide mixture formulas on the market are here! Worth saving!

I. Acetochlor + Atrazine mixture

Although atrazine alone has a good effect on controlling weeds in corn fields, it also has quite a few problems:

(1) Atrazine has high water solubility and high leaching potential, and easily pollutes groundwater.

(2) It may cause phytotoxicity to the following wheat crop and has poor control efficacy against crabgrass.

Using the acetochlor + atrazine mixture, because the content of atrazine alone is reduced, it can broaden the weed control spectrum and improve efficacy. The total content of the compounded formulation of acetochlor and atrazine (or propisochlor and atrazine) is 40%-60%, and the dosage is 125-450 ml/mu. Its function is positioned as pre-emergence closed treatment in corn, and under moist conditions it can control weeds with fewer than 3 leaves.

Among the mixtures, the better-performing ratios are 20% acetochlor + 20% atrazine, 200-250 g/mu. 18% propisochlor + 23% atrazine, 200-250 g/mu; this ratio is the best mixing ratio of the two, with the best overall effect. The mainstream mixtures for pre-emergence closed treatment in corn fields include: acetochlor + atrazine, propisochlor + atrazine, and butachlor + atrazine. The closed-treatment activity decreases from top to bottom, while safety is the opposite. Among these three formulas, relatively speaking, butachlor + atrazine is the safest.

In addition, there are also metolachlor · acetochlor · atrazine, cyanazine · atrazine, and others, but these are not mainstream formulas (Note: corn field herbicides containing cyanazine are prone to causing phytotoxicity when applied after the 4-leaf stage of corn, and in waterlogged corn fields the phytotoxicity is even more severe). When using them, it is best to choose formulas with high atrazine content and low amide content, which have better weed-killing effects, higher safety, and longer closed-treatment duration.

The table below analyzes the advantages and disadvantages of different acetochlor + atrazine ratios:

1. Acetochlor and atrazine 1:1 mixture:

The earliest produced herbicide mixtures of this type were acetochlor + atrazine mixture and acetochlor + atrazine suspension concentrate, which can be used after corn sowing and before emergence, and in the early post-emergence stage of corn to control annual grass weeds and broadleaf weeds, and are safe for corn and subsequent crops.

Similar products include butachlor + acetochlor + atrazine, butachlor + atrazine, alachlor + acetochlor + atrazine, metolachlor + atrazine, propisochlor + atrazine, and others.

2. Acetochlor and atrazine 2:3 mixture:

This herbicide mixture can be used after corn sowing and before emergence, and in the early post-emergence stage of corn to control annual grass weeds and broadleaf weeds in corn fields, and is safe for corn.

In particularly dry years it may reduce safety to the following wheat crop. A product with similar performance is the chlorotoluron + acetochlor + atrazine mixture, which can greatly improve safety to the following wheat crop, but cannot be used post-emergence in corn.

3. Action characteristics of acetochlor + atrazine mixtures:

(1) After corn sowing and before emergence, or in the early post-emergence stage, soil closed treatment effectively controls many kinds of annual grass weeds and broadleaf weeds.

(2) It can be absorbed by the roots, buds, stems and leaves of weeds, and is suitable for closed treatment weeding in many kinds of fields and on high wheat stubble and dry highland plots.

(3) Target weeds: it can control many kinds of annual grass weeds and broadleaf weeds in corn fields.

II. S-metolachlor + Terbuthylazine

This mixture has additive effects on 4 weeds including lambsquarters, copperleaf, upland barnyardgrass, and foxtail. The best ratio is 37.5:62.5, and it is safe for corn.

Used for spring corn, soil spray after sowing and before emergence to control annual weeds, with an application dosage of 1400-1800 g/ha of active ingredient.

III. Nicosulfuron + Atrazine mixture

For the ratio of nicosulfuron to atrazine, when the ratio of their dosages per unit area is 1:12, the effect is best and corn is in the safest state. When the dosage ratio of atrazine to nicosulfuron is less than 6:1, corn cannot fully overcome the phytotoxicity of nicosulfuron and phytotoxicity is likely to occur.

There are many mixtures of this product on the market, such as 3% nicosulfuron + 17%-20% atrazine, with a specification of about 100 g. This formula reduces the amount of nicosulfuron used, relatively improves the safety factor, greatly improves control efficacy against broadleaf weeds, and the cost is also relatively reasonable. The ratio of 2% nicosulfuron + 20% atrazine also has a relatively good effect, with a formulation dosage of 180-200 g/mu, good weed-killing effect, and also a certain closed-treatment function.

In the mountainous areas of the south, 4% nicosulfuron + 48% atrazine bagged powder is generally used more, with a formulation dosage of 90 g/mu, which solves the situation of weeds regreening due to low temperatures and poor soil moisture in mountainous areas, and at the same time has a certain closed-treatment function, with a high safety factor for corn.

In addition, many manufacturers use the registration certificate of 38% atrazine and add 3-4% nicosulfuron. At present, in most areas, insensitive broadleaf weeds such as velvetleaf and purslane do not account for a large proportion of weeds in corn fields, so nicosulfuron + atrazine is evaluated well in the market. Its function is positioned as post-emergence control of small weeds in corn with a certain closed-treatment function.

Action characteristics of nicosulfuron · atrazine mixtures:

1. After corn sowing and before emergence, or in the early post-emergence stage, stem and leaf treatment plus soil closed treatment effectively controls many kinds of annual grass weeds and broadleaf weeds, with outstanding effect on purple nutsedge and perennial grass weeds.

2. Kills weeds, provides closed treatment, requires dry conditions, is tolerant of wheat stubble, and one application keeps a whole season free of weed damage.

3. Target weeds: it can control purple nutsedge, annual and perennial grass weeds, and annual broadleaf weeds in corn fields.

IV. Nicosulfuron + MCPA

When mixed with nicosulfuron, generally 50 g of 56% MCPA can ensure a relatively good effect. Nicosulfuron + MCPA has advantages in fields with relatively many troublesome weeds such as purple nutsedge, field bindweed, reed, and Cyperus difformis in conventional corn fields, and its control efficacy against other broadleaf weeds is also outstanding. In addition, it also has good control efficacy against volunteer wheat seedlings and shattering sorghum. When used, it is less affected by high wheat stubble, drought, soil structure, and cultivation conditions, and is safe for subsequent crops with no residue.

However, note that hormone-type herbicides (such as MCPA, 2,4-D, fluroxypyr, dicamba, clopyralid, etc.) used in corn fields can cause relatively severe phytotoxicity when applied early or too late in corn. Generally, they cannot be used during the seedling stage before 4 leaves, and cannot be used after jointing. Use before 4 leaves can easily lead to weak meristem tissue, making corn prone to lodging. Use after jointing can cause deformity of aerial roots in corn and other crops, affecting stability, and in severe cases making tasseling impossible.

V. Nicosulfuron + Propisochlor · Atrazine / Acetochlor · Atrazine / Butachlor · Atrazine

A formula that truly has both stem and leaf treatment and closed-treatment effects, for example 2% nicosulfuron + 40% propisochlor · atrazine, 200 g per mu, but phytotoxicity is relatively likely to occur, especially the formula of nicosulfuron + acetochlor? atrazine. The safest is the formula of nicosulfuron + butachlor · atrazine.

Next is nicosulfuron + propisochlor? atrazine. Propisochlor also causes relatively severe phytotoxicity to corn. The better domestic ratio is: 2% nicosulfuron + 10% butachlor + 20% atrazine, 150 g/mu. 2-2.5% nicosulfuron + 20% propisochlor + 30% atrazine, 150 g/mu. The three-way mixture has a synergistic effect on crabgrass and redroot pigweed. Its function is positioned as post-emergence control of both grass and broadleaf weeds, while also having an excellent closed-treatment effect. This formula can effectively control troublesome weeds and common grass and broadleaf weeds such as green foxtail, creeping thistle, sowthistle, barnyardgrass, foxtail, goosegrass, amaranth, and goosefoot.

Nicosulfuron · butachlor · atrazine: Relevant formula screening reports show that when the three are mixed, butachlor:atrazine:nicosulfuron = (10-20):(10-20):(1-2), there is a partial synergistic effect on broadleaf weeds and an additive effect on grass weeds, and the dosage of the three active ingredients can be reduced. It is safe for corn and has no effect on growth. Field trials show that when applied as a uniform stem and leaf spray at the 3-5 leaf stage of corn and the 2-4 leaf stage of weeds, it has good control efficacy against annual weeds such as barnyardgrass, foxtail, goosefoot, and black nightshade.

VI. Nicosulfuron + Mesotrione + Atrazine

The registered contents are roughly 1-3% nicosulfuron + 3-7% mesotrione + 16-20% atrazine, in order to achieve control of both grass and broadleaf weeds. Mixed use of the three has the characteristics of broadening the weed control spectrum, reducing the dosage of single agents, and improving crop safety. The determination of the best ratio is greatly affected by the species of test weeds.

The characteristics of this formula are:

1. After corn sowing and before emergence, or in the early post-emergence stage, stem and leaf treatment plus soil closed treatment effectively controls many kinds of annual grass weeds and broadleaf weeds, with outstanding effect on purple nutsedge and perennial grass weeds.

2. Fast weed-killing speed, thorough kill with no rebound, low-temperature tolerant, drought resistant, can replace all post-emergence corn herbicides, is the most ideal one-time herbicide, saving time, labor, and money.

3. Three action targets, so weeds are not prone to developing resistance.

4. Target weeds: it can control purple nutsedge, annual and perennial grass weeds, and annual broadleaf weeds in corn fields.

VII. Mesotrione + Atrazine

A relatively good domestic formula is 16.7% atrazine + 3.3% mesotrione, 260 g per mu. 22.7% atrazine + 2.3% mesotrione, 250-300 g/mu. The purpose of adding atrazine is to reduce regreening of grass weeds and broaden the weed control spectrum.

These three formulas still have only moderate control efficacy against some grass weeds, especially no effect on foxtail and similar weeds. The key point of use is to apply the herbicide early, and at the same time, according to the weed spectrum, if the main weeds in the field are crabgrass, goosegrass, and foxtail, resolutely choose nicosulfuron-type products to improve control efficacy. The main selling point is fast visible effect, with higher safety than nicosulfuron-type products.

VIII. Nicosulfuron + Bromoxynil octanoate + 2,4-D butyl ester

Mixing the three can improve weed control efficacy and response speed and can improve crop safety. The best mixing ratio of the three is within the range of bromoxynil octanoate:nicosulfuron:2,4-D butyl ester = (17:4:9)-(15:4:11). Different ratios basically show additive effects on barnyardgrass and redroot pigweed.

Its characteristics are:

1. Broad weed control spectrum, high activity, kills both small and large weeds, kills both common and stubborn weeds, suitable for areas with relatively many broadleaf weeds in the field (such as small thistle, velvetleaf, copperleaf, Asiatic dayflower, field bindweed, etc.).

2. Three components provide multi-site control of weeds, resulting in thorough weed control.

3. Fast visible effect. The effect on broadleaf weeds is very fast, generally showing results in 2-3 days and killing weeds in 5-7 days. For grass weeds, it generally shows results in 7 days, with the heart leaves turning yellow, and kills weeds in 10—15 days, but the kill is thorough, with the stem base rotting.

However, under abnormal conditions such as high temperature and drought, waterlogging in the field, or weak seedlings, phytotoxicity is likely to occur, with yellow or white spots appearing on the upper leaves of corn. At the same time, when applying, pay attention to the impact on surrounding broadleaf crops.

Other formulas containing bromoxynil octanoate, such as: nicosulfuron + bromoxynil octanoate + atrazine = 3:13:22. This formula reduces drift phytotoxicity to surrounding broadleaf crops, relatively improves safety, and at the same time improves control efficacy against some grass weeds, has a certain closed-treatment effect, and has a relatively longer lasting effect.

IX. Mesotrione + (S-)Metolachlor / Propisochlor / Acetochlor / Butachlor + Atrazine

Safety: mesotrione · acetochlor · atrazine < mesotrione · propisochlor · atrazine < mesotrione · butachlor · atrazine < mesotrione · (S-)metolachlor · atrazine, while the weed control effect is exactly the opposite.

A relatively good formula for mesotrione · propisochlor · atrazine is: 3.5% mesotrione + 15% propisochlor + 15% atrazine, 200 g/mu. A formula that truly has both stem and leaf treatment and closed-treatment effects, its function is positioned as post-emergence control of older broadleaf weeds, especially outstanding against troublesome broadleaf weeds, also controlling some grass weeds, while having an excellent closed-treatment effect.

It is relatively safe for hybrid corn, sweet corn, waxy corn, and popcorn. This formula has significant effects on velvetleaf, amaranth, goosefoot, smartweed, crabgrass, barnyardgrass, sedge, smallflower melic, cruciferous weeds, leguminous weeds, and others.

X. Formulas containing fluroxypyr

For example, 3% nicosulfuron + 5% fluroxypyr + 20% atrazine, 120 ml/mu. Because alligator weed and field bindweed are relatively abundant in some areas, such as southern Sichuan and Chongqing, this formula is more commonly used in areas with abundant alligator weed and field bindweed.

It can control annual grass weeds and broadleaf weeds, and also has a relatively good effect on troublesome broadleaf weeds. However, pay attention to the application timing of fluroxypyr in corn fields. When applied early or too late in corn, phytotoxicity is relatively severe. Generally, it cannot be used during the seedling stage before 4 leaves, and cannot be used after jointing.

In addition, there is also the formula of mesotrione · atrazine + fluroxypyr 1+1. This formula has only moderate control efficacy against grass weeds, especially foxtail, and crabgrass and goosegrass beyond the 4-leaf stage. It is greatly affected by temperature, and at low temperatures the speed of visible effect slows down noticeably.

It is mainly positioned as post-emergence control of most broadleaf weeds, especially in plots with abundant alligator weed and field bindweed, also controlling some young grass weeds, with a certain closed-treatment effect.

XI. Nicosulfuron + Dicamba

The mode of action of dicamba on weeds is similar to that of 2,4-D butyl ester and MCPA. It can control catchweed bedstraw, large vetch, cocklebur, creeping thistle, horsetail, field bindweed, eclipta, and others. The currently registered formula is 30% dicamba + 10% nicosulfuron, 150-210 g/ha. This formula focuses on controlling troublesome broadleaf weeds such as creeping thistle, field bindweed, and cocklebur, and has certain advantages in Northeast China. The main problem currently facing promotion is the relatively high selling price.

XII. Nicosulfuron + Bromoxynil octanoate

The commonly used formula is 4% nicosulfuron + 16% bromoxynil octanoate. After mixing the two in an appropriate ratio, the weed control spectrum can be broadened, and it has good control efficacy against both grass weeds and broadleaf weeds, with an additive effect on barnyardgrass. Note: Do not use in high-temperature weather, when rain is expected within 6 hours, or when the temperature is below 8 degrees C or near severe frost.

XIII. Nicosulfuron + Metribuzin

The ratio of metribuzin to nicosulfuron is relatively good between (1.25-5):1. The mixed use of metribuzin and nicosulfuron has a slight synergistic effect on barnyardgrass, and an additive effect on crabgrass, redroot pigweed, and velvetleaf. Mixed use of the two can complement each other's advantages in production.

XIV. Nicosulfuron + Atrazine + 2,4-D butyl ester

Atrazine:nicosulfuron:2,4-D butyl ester has a relatively good effect within the ratio range of (2-4):1:(2-6), showing additive and slightly synergistic effects on crabgrass and barnyardgrass, and additive effects on redroot pigweed and velvetleaf. Mixed use of the three can complement each other's advantages in production, delay herbicide resistance, and reduce use cost.

XV. Other precautions

Mixing 2,4-D butyl ester into corn field herbicide mixtures to enhance efficacy: when mixed into pre-emergence closed treatment, the active ingredient dosage per mu is 30-50 g. If low-temperature weather and leaching in sandy soil are not encountered, phytotoxicity generally will not occur.

For post-emergence mixing of 2,4-D butyl ester into nicosulfuron and atrazine, generally 40-50 g of a 72% formulation is used per mu. Improper application timing, weak seedlings, drought, and the dual action of nicosulfuron make phytotoxicity relatively likely to occur.

The above is an introduction to almost all corn field herbicide mixture formulas on the market. Through this article, farmers can gain a certain understanding of the types and ratios of herbicides, as well as the advantages and disadvantages of herbicides in various ratios. In corn fields, attention should be paid to timely weed control to prevent weeds from competing with corn for nutrients, causing problems such as excessive vegetative growth without fruiting or small ears.