Bensulide

Bensulide is a selective organophosphate herbicide used for controlling a wide range of weed species. It is primarily used in the cultivation of certain crops, including vegetables, fruits, and ornamental plants. Bensulide works by inhibiting the growth of weed seedlings, thereby preventing them from competing with the desired crops for resources.

Chemical Properties

Bensulide is an organophosphate compound, meaning it contains phosphorus. It has the chemical formula C12H21O3PS2 and is also known by its IUPAC name S-2-(phenylsulfonylamino)ethyl O,O-diisopropyl phosphorodithioate. It is a colorless to amber liquid with a slight aromatic odor.

Mode of Action

Bensulide acts as a pre-emergence herbicide, meaning it is applied to the soil before the weed seeds germinate. It inhibits the growth of weed seedlings by disrupting the process of cell division in their root tips. This prevents the weeds from establishing a strong root system and competing with the crops for water and nutrients.

Usage

Bensulide is used in the cultivation of a variety of crops. These include vegetables such as lettuce, carrots, and onions; fruits such as strawberries and citrus; and ornamental plants such as roses and chrysanthemums. It is typically applied to the soil surface and then incorporated into the soil to a depth of 1 to 2 inches.

Safety and Environmental Impact

Like other organophosphate compounds, bensulide can be toxic to humans and animals if ingested, inhaled, or absorbed through the skin. It is classified as a Category III toxin by the Environmental Protection Agency (EPA), indicating a low to moderate level of toxicity. Bensulide is also toxic to fish and other aquatic organisms.

In the environment, bensulide is moderately persistent, with a half-life in soil of 60 to 120 days. It has low mobility in soil, meaning it is unlikely to leach into groundwater. However, it can be transported in surface runoff, posing a risk to aquatic ecosystems.

Regulation

In the United States, bensulide is regulated by the EPA under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). It is classified as a Restricted Use Pesticide (RUP), meaning it can only be used by certified applicators or under the direct supervision of a certified applicator.

See Also

• Organophosphate
• Herbicide
• Weed control
• Environmental Protection Agency