Aminopyralid

Aminopyralid is a selective herbicide widely used in agriculture to control broadleaf (dicotyledonous) weeds. It is known for its high efficacy at low doses, persistence in the soil, and residual action.

Common name (ISO): Aminopyralid

Synonyms: DE-750; XDE-750; XR-750 (development codes); Chaparral and other

Gross chemical formula: C6H4Cl2N2O2

Number CAS: 150114-71-9

Chemical class: A herbicide from the pyridine carboxylic acid (or picolinic acid) family, which includes compounds such as clopyralid, picloram, and triclopyr. It is classified as an organochlorine pesticide with plant growth regulator properties.

Development history: Developed by Dow AgroSciences (now Corteva Agriscience) as part of a series of synthetic auxinic herbicides, aminopyralid emerged from research to improve selectivity and persistence compared to precursors such as clopyralid. It was commercially launched in 2005 under the name Milestone in the US, expanding to products such as GrazonNext HL.

Mode of action: It acts as a synthetic plant growth regulator, mimicking the natural plant growth hormone (auxin). Absorbed by leaves and roots, it is translocated systemically, disrupting metabolic growth processes such as cell division and elongation, leading to deformation, growth inhibition, and selective death of broadleaf weeds. It does not significantly affect grasses (monocotyledons), making it selective for pastures. Its post-emergence action is residual, with mobility in the soil.