Corn herbicide: how to choose and how to apply

What are herbicides

The very term “herbicide” refers to a chemical used to kill plants. Herbicide-based preparations allow you to effectively and quickly get rid of unwanted vegetation. According to the principle of impact on plants, they are divided into drugs of selective (selective) and continuous action.

The latter are capable of killing all types of vegetation. The scope of their application is the destruction of unnecessary plantings around and on the territory of industrial facilities: on roads, airfields, under power lines, in reservoirs, canals. Selective preparations are designed to protect crops from weeds. They are used in the cultivation of corn.

Treatment with herbicides is popularly called “chemical weeding”. This is a really good comparison, because after the application of weed control agents there is no trace left.

With proper use, they are completely safe for crops, but it often happens that not only weeds, but also cultivated plants are destroyed. This outcome is possible if the herbicide is chosen incorrectly, or an excessive amount of it has been applied.

It is important to understand that any herbicide is a fairly strong chemical designed to kill resistant weeds. If crops of economic importance are treated with such a preparation, then there is a high probability that the plants will stop growing, or the crops will simply die from burns. As for corn, its processing makes sense only if there are a lot of weeds, and other, more gentle methods of dealing with them cannot be applied. Typically, this situation occurs when corn is grown in fields on a very large scale.

A wide variety of corn herbicides are now available, making it difficult to select the best one from the range. The most common are preparations based on 2,4-D amine salt, clopyralide, sulfonylurea, acetochlor. Each of the active substances has its own characteristics of application.

Amine salt is effective with good hydration. During drought, this herbicide can partially burn corn, as well as significantly inhibit its growth. The principle of action of the drug is not to dry the weeds, but to stop their growth and gradual death. Many business executives are perplexed and disappointed by the fact that even a few days after the application of the product, the weeds remain green and unharmed. However, one should not think that the herbicide is ineffective, it just takes 30-40 days for the complete death of plantings.

Clopyralid is a very highly potent post-emergence herbicide. Sulfonylureas are systemic drugs with a very broad spectrum of action with high selective activity against weeds. If you use these tools in tandem, the result can be simply amazing.

The choice of preparation depends not only on the active substance, but also on the purpose of its administration, the type of weeds and the time of application.

Corn can be processed in the following ways:

• The trimmer is a universal systemic preparation for the control of major annual and perennial dicotyledonous weeds. It is applied after germination when the plants reach 3-5 leaves.

• Kvazar is a systemic post-emergence preparation against annual and perennial weeds.

• Miranda is a complex preparation in the form of a suspension, intended for the destruction of weeds already in crops.

• Aztec is a soil herbicide used during corn sowing.

• Triton is a preparation for combating annual and annual weeds. The principle of action is to absorb the substance by leaves and quickly move to growth points, which leads to the rapid death of weeds.

• Turbin is a highly active preparation against annual grass weeds. Used in crops.

This is not the whole list of herbicides. There are also preparations that are applied to the soil even before sowing corn: Merlin, Saga. They are very convenient to use, as they relieve crops of weeds at the most necessary moment – at the initial stage of growth. However, processing with such means has a significant disadvantage – excessive drying of the soil.

Video “How to apply herbicides”

In this video, a plant expert will show you how to properly apply herbicides.

Types of weed

Corn belongs to heat-loving crops. Many gardeners grow it from seedlings, and plant it in open ground with the onset of warm days.

When cultivating corn on a large scale, it is not possible to grow seedlings, so the grains are sown directly into the ground in late spring. In this case, the first sprouts may appear only by mid-June.

Late planting and slow emergence mean that corn is more susceptible to weeds than other crops, which have time to grow well in the spring.

Weeds, like cultivated plants, are divided into annuals and perennials, which in turn are divided into monocots and dicots. The annual monocotyledonous weeds that most often attack corn include common barnyard grass, bristle grass, wild oat, and millet variety. Of the dicotyledonous annuals in plantings of corn, the following most often grow: blue cornflower, mountaineer, peas, jaundice, gauze, amaranth, chistets and many others.

Of the perennials, corn is often replaced by field thistle (sow thistle), bindweed (popularly called birch), dandelion, euphorbia, wormwood, ambrosia. Horsetail is often found in moist soil.

It is very difficult to get rid of these plants. Even repeated herbicide treatments do not always remove these weeds, as they are capable of producing new shoots. Another difficulty in weed control is that many species grow quite late – after the plantings have been processed. In addition, most weeds are prone to self-sowing, so the corn field has to be worked several times per season.

Processing instructions

Since any herbicide is a very active chemical, its application must be extremely careful and correctly dosed. Before using the drug, you should read the instructions on the package. For each agent, there is an exact dosage, method of application and types of weeds from which it is effective.

Corn can be cultivated in two ways: embedding in the soil and spraying weeds. In both cases, liquid solutions are used, which are diluted in the concentration recommended by the instructions. 

For spraying, solutions of a stronger concentration are used, since under the influence of wind, rain and other natural factors, the herbicide is partially removed from the weeds. It is noted that when sprayed on the leaves, no more than 30% of the drug remains. Both methods have their pros and cons. The advantages of spraying include the exclusion of soil pollution, and the fact that weeds die more slowly when spraying is considered a significant disadvantage.

If the herbicide is applied to the soil, then the solution must be carefully distributed over the surface so that it penetrates no lower than the planted grains. When applying soil preparations for corn, it is necessary to pay attention to the conditions under which they are active. For example, many of these herbicides do not show their activity in dry soil. If there is no rain, or they are very rare, there is a high probability that by the time the soil is moistened, the active components have already disappeared, and their application will be useless. This also applies to preparations based on 2,4-D amine, dicamba, which are active only in moist soil. In addition, they can be used at strictly defined times – when 3-5 leaves appear on the sprouts.

Almost all drugs are applied in the morning or in the evening, since a prerequisite for their safe use is a temperature regime not exceeding 25 ° C. At a higher degree, the agents have a toxic effect not only on corn, but also on the one who was engaged in the processing of plants. Therefore, when working with such substances, it is necessary to protect yourself – wear protective clothing, shoes and a respirator.

It is important to understand that the introduction of herbicides into the soil for corn is an irreversible process. Their validity period lasts from 1 to 2 months. At the same time, active substances penetrate into the roots, stems and leaves, which, of course, affects the quality of the crop. Therefore, corn is no longer processed approximately 1–1,5 months before harvest. If corn is planned to be harvested in milky maturity, then the use of drugs is stopped no later than a month before the collection of young heads.

Video “Protection of corn from weeds”

This video is a simple visual aid to effectively protect corn from weeds using technology based on Meister.