An herbicide is a chemical or natural product that is used to inhibit or interrupt the development of unwanted plants, also known as weeds, on land where crops are or will be grown.
A weed is understood as any plant that grows and develops in place or time that is not desired by humans. Most weeds have the same characteristics: they are easy to spread, since they often have mechanisms that rely on the wind or water to disperse them, and they are very resistant due to their high seed production.
Among the problems that weeds create are crop reduction because they compete for the use of resources such as space, light, water, etc. They also affect the harvest process itself, which means that theyhinderor slow down the removal of the crop, and can also increase costs, because if they are not treated in time, they require a larger investment in time and money to get rid of them.
How to use an herbicide
To choose an herbicide, youmust bear in mind the harvest conditions, the type of weeds that you want to control, as well as the physical features of the soil. You can find herbicides on the market in solid or liquid formulations; it depends on the active ingredients and its application form.
Thereare well over 100 active ingredients or molecules found in registered herbicides today, and commercialized herbicides are made of different combinations or formulationsof these active ingredients.
There are three names on herbicide labels:
- Chemical name, which describes the herbicidal compound’s chemical composition.
- Common name, which is the generic name given to the active ingredient, approved by the corresponding authorities.
3.Trade name. For example, the herbicide sold under the trade name Glifos Titan has the common nameGlyphosate, which is its active ingredient, and the chemical name N – (phosphonomethyl) glycine.
The quantity of active ingredient in percentage and grams of active ingredient per liter orkilograms of the commercial product is indicated on the herbicide label. The herbicide formulation is also indicated on this product label. It can also be designated by one or several letters after the trade name.
Types of herbicides: nonselective vs. selective herbicide
There are several types of herbicides depending on the ways they are classified, how they are used, their chemical properties and mode of action. Herbicides can be broadly classified as nonselective or selective depending on the types of weeds they target.
A nonselective herbicide is a plant protection product that is applied with the purpose of controlling all types of weeds and plants indiscriminately. These herbicides are generally used for clearingterrain. By using them, you get complete control of annual and perennial weed species. It is usually sold in liquid format, and the dose will vary by weed type. The active material presented in the majority of these herbicides is glyphosate. They are normally used for land without crops, such as industrial zones, highways, etc.If they are applied on land with crops, it needs to be applied without affecting them. The crop selectivity and the weed control spectrumare often used in herbicides classifications. For example, herbicides for cereal crops and herbicides for broadleaf weeds.
Selective herbicidesare used to remove a particular weed type, while leaving the rest of the crop intact after being applied. For example, broadleaf weed (dicot) or narrow leaf/grassy (Cynodon, Cyperus, etc.) selective herbicides.
This kind of distinction between selective and nonselective herbicides will depend on the concentration or the applied dose. This is because a nonselective herbicide can be used as a selective one at low concentrations, and a selective one can eliminate any kind of plant if it is used with a high enough dose.