defoliant(redirected from Chemical defoliants)
Also found in: Dictionary, Thesaurus, Encyclopedia.
a chemical used to remove the leaves from plants to facilitate mechanical harvesting. The early defoliants, especially arsenical compounds, presented serious hazards if the plants were later fed to livestock or if the spray drifted to nearby pasture paddocks. Modern defoliants are nontoxic if used according to manufacturer's recommendations. See mcpa, tributyl triphosphorotrithioite, thidiazuron.