Arsenic and its compounds, especially the trioxide, are used in the production of pesticides ( treated wood products ), herbicides, and insecticides.

Though herbicides are chemicals, they are often grouped with biological warfare and chemical warfare because they may work in a similar manner as biotoxins or bioregulators and also because the Army Biological Laboratory tested them and the Army's Technical Escort Unit which all chemical, biological, radiological ( nuclear ) materials.

Nowadays, the agencies that are responsible for the biotechnology regulation are: US Department of Agriculture ( USDA ) that regulates plant pests and medical preparation from living organisms, Environmental Protection Agency ( EPA ) that regulates pesticides and herbicides, and the Food and Drug Administration ( FDA ) which ensures that the food and drug products are safe and effective

In agriculture, genetically engineered crops are created to possess several desirable traits, such as resistance to pests, herbicides, or harsh environmental conditions, improved product shelf life, and increased nutritional value.

Among the most significant soil contaminants are hydrocarbons, heavy metals, MTBE, herbicides, pesticides and chlorinated hydrocarbons.

The cotton industry relies heavily on chemicals, such as herbicides, fertilizers and insecticides, although a very small number of farmers are moving toward an organic model of production, and organic cotton products are now available for purchase at limited locations.

Pesticides are categorized into four main substituent chemicals: herbicides ; fungicides ; insecticides and bactericides.

Many modern chemical herbicides for agriculture are specifically formulated to decompose within a short period after application.

Even when herbicides which have low toxicity to birds are used, they decrease the abundance of many types of vegetation on which the birds rely.

Generally, these are the fastest acting herbicides.

* Systemic herbicides are translocated through the plant, either from foliar application down to the roots, or from soil application up to the leaves.

They are capable of controlling perennial plants and may be slower-acting, but ultimately more effective than contact herbicides.

* Soil-applied herbicides are applied to the soil and are taken up by the roots and / or hypocotyl of the target plant.

# Preplant incorporated herbicides are soil applied prior to planting and mechanically incorporated into the soil.

# Pre-emergent herbicides are applied to the soil before the crop emerges and prevent germination or early growth of weed seeds.

# Postemergent herbicides are applied after the crop has emerged.

The ACCases of grasses are sensitive to these herbicides, whereas the ACCases of dicot plants are not.

Like other acid herbicides, current formulations use either an amine salt ( often trimethylamine ) or one of many esters of the parent compound.

However, herbicides with low residual activity ( i. e., that decompose quickly ) often do not provide season-long weed control.

In addition to health effects caused by herbicides themselves, commercial herbicide mixtures often contain other chemicals, including inactive ingredients, which have negative impacts on human health.

The health and environmental effects of many herbicides is unknown, and even the scientific community often disagrees on the risk.

The plant is edible, but often sprayed with herbicides.

The other most common color coded Ranch Hand herbicides were Agent Blue ( cacodylic acid ) that was primarily used against food crops, and Agent White ( picloram ) which was often used when Agent Orange was not available.

It is resistant to many herbicides ; in fact, herbicide use often selects for horsenettle by removing competing weeds.

Before the introduction of broad-leaf herbicides, white clover was more often added to lawn seed mixes than it is today, as it is able to grow and provide green cover in poorer soils where turfgrasses do not perform well.

Triazine compounds are often used as the basis for various herbicides such as cyanuric chloride ( 2, 4, 6-trichloro-1, 3, 5-triazine ).

Even though herbicides are chemicals, due to their mechanism of action ( growth regulators ) they are often considered a means of biological warfare.

Although ecologically there is no reason to consider it a pest, foresters sometimes consider the striped maple to be unwanted, often cutting it or applying herbicides to kill it.

65 % of the herbicides used contained 2, 4, 5-Trichlorophenoxyacetic acid that was found to have been contaminated with 2, 3, 7, 8-Tetrachlorodibenzodioxin, a human carcinogen by all routes of exposure.

The Da Nang, Bien Hoa and Phu Cat Air bases are still heavily contaminated with dioxin from the herbicides and have been placed on a priority list for containment and clean-up by the Vietnamese government.

During the Vietnam War, between 1962 and 1971, the United States military sprayed nearly of material containing chemical herbicides and defoliants mixed with jet fuel in Vietnam, eastern Laos and parts of Cambodia, as part of Operation Ranch Hand.

The lack of herbicides with broad-spectrum activity and no crop injury was a consistent limitation in crop weed management.

Pioneer Hi-Bred has marketed corn hybrids with tolerance to imidazoline herbicides under the trademark " Clearfield "-though in these hybrids, the herbicide-tolerance trait was bred using tissue culture selection and the chemical mutagen ethyl methanesulfonate not genetic engineering.

The infertility of most of the soils has required heavy inputs of chemical fertilisers, particularly superphosphate, insecticides and herbicides, which — with the ensuing damage to invertebrate and bacterial populations, and compaction of soils through heavy machinery and hoofed mammals — has done great damage to the fragile soils.

It also provides weed control throughout the growing season during the maturation of the crop plants, unless such weed control is instead achieved with low-till or no-till methods involving herbicides.

The risk of Parkinson's disease has been shown to increase with occupational exposure to herbicides and pesticides.

, studies on phenoxy herbicides were too few to accurately assess the risk of many types of cancer from these herbicides, even though evidence was stronger that exposure to these herbicides is associated with increased risk of soft tissue sarcoma and non-Hodgkin lymphoma.

* Contact herbicides destroy only the plant tissue in contact with the chemical.

Depending on the application, they may be less effective than synthetic herbicides and are generally used along with cultural and mechanical weed control practices.

Now, it is mainly used in a blend with other herbicides to allow lower rates of herbicides to be used ; it is the most widely used herbicide in the world, and third most commonly used in the United States.

Still used because of its low cost and because it works well on a broad spectrum of weeds common in the US corn belt, atrazine is commonly used with other herbicides to reduce the overall rate of atrazine and to lower the potential for groundwater contamination ; it is a photosystem II inhibitor.

The usage of herbicides can be combined with other methods of eradication and control, such as mowing, grazing, or burning, which can allow for an easier application of the chemical to the weakened plants.

The government has taken measures to halt or slow down the cultivation of opium poppies and cannabis by spraying crops with herbicides, which threaten the populations of many different species.

Monsanto is the largest producer of glyphosate herbicides in the United States through its Roundup product line, which is used to kill weeds, especially annual broadleaf weeds and grasses that compete with commercial crops.

The vegetation would have been cut regularly or sprayed with herbicides, so that trains were not obstructed and to lessen the risk of fire.

This includes woody material, pernicious weeds, diseased material and material treated with persistent pesticides and herbicides.

* Contact herbicides destroy only that plant tissue in contact with the chemical spray.