What does diquat mean?
Diquat is a nonselective, fast-acting herbicide belonging to the bipyridyl family of chemicals. Marketed chiefly as its dibromide salt, it kills plants by contact rather than through root uptake: when absorbed into green tissue and exposed to light, it disrupts photosynthesis in a way that generates highly reactive oxygen species, rapidly desiccating leaves and stems. Because it binds tightly to soil particles and leaves little residual activity, it has been widely used for clearing aquatic weeds in ponds and waterways and for pre-harvest desiccation of crops such as potatoes and seed plants. The name is largely confined to agricultural, regulatory, and scientific contexts, appearing in discussions of pesticide safety, water management, and food-residue limits, where its handling requires care owing to its toxicity to humans and animals.
nounA fast-acting contact herbicide of the bipyridyl family, used to control aquatic weeds and to desiccate crops such as potatoes before harvest.
- The bipyridyl herbicide used as a fast-acting contact weedkiller and crop desiccant.
"The farmer sprayed diquat on the pond to clear the choking mats of invasive waterweed."
"Regulators tightened limits on diquat residues found in treated potatoes."
"Because diquat acts only on the tissue it touches, it is valued where soil residual activity would be undesirable."
The plural is rare and appears mainly when distinguishing different formulations or residues of the compound.
"Analysts compared diquats from several commercial formulations."
Diquat destroys plant cells by hijacking sunlight itself, churning oxygen into destructive free radicals every time the weed photosynthesizes.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of diquat
The name diquat was coined commercially in the mid-twentieth century as a contraction of 'diquaternary', referring to the two quaternary nitrogen atoms in its bipyridyl molecular structure. It combines the Greek-derived prefix 'di-', meaning two, with a shortened form of 'quaternary', ultimately rooted in the Latin 'quaterni', meaning four at a time. The same naming pattern produced its chemical sibling paraquat, and both terms entered English usage alongside the postwar expansion of synthetic herbicides.
How diquat is actually used
Diquat is a technical and agricultural term, encountered mainly in farming, horticulture, environmental regulation, and chemistry rather than everyday speech. It is typically applied as the dibromide salt and carries connotations of industrial weed control.
Easily confused with diquat
Paraquat is a closely related bipyridyl herbicide that is far more toxic to humans; diquat is chemically similar but generally less acutely poisonous.