metiram

Metiram is a fungicide in the dithiocarbamate class used to control a range of fungal diseases on crops and ornamental plants. It is typically applied as a protective foliar spray and provides contact activity with limited systemic movement in the plant. Metiram formulations are used on crops such as grapes, apples, pears, stone fruits, strawberries, tomatoes, and various ornamentals.

Chemistry and formulation: Metiram is an organosulfur compound belonging to the ethylenebisdithiocarbamate family. Commercial products are formulated as metal-containing salts or complexes, and may be used alone or in mixtures with other pesticides depending on local regulations and crop target.

Mode of action and limitations: The precise mechanism is not fully understood, but dithiocarbamates are thought to inhibit fungal enzymes and create protective films on surfaces that deter infection. Their activity is largely protective and non-systemic.

Safety and environment: Metiram can be irritating to skin and eyes and may be toxic to aquatic organisms. Like other dithiocarbamates, it can form breakdown products such as ethylenebis(dithiocarbamates) including ETU under certain conditions, which has prompted regulatory scrutiny. Use is subject to label requirements, protective equipment, and adherence to pre-harvest intervals and residue limits.

Regulatory status: Regulatory status varies by country. Some jurisdictions have restricted or suspended certain uses, while others permit application under specific conditions and restrictions.

See also: Ethylenebisdithiocarbamates, ziram, maneb, mancozeb.