Benfluralin is an herbicide of the dinitroaniline class. The mechanism of action of benfluralin involves pre-emergent inhibition of mitosis, root and shoot development,[1] same as trifluralin, from which benfluralin was developed in 1963.[2]
It is used to control grasses and other weeds. Annual use in the United States was approximately 700000lb in 2004,[3] down from 1200000lb in 1974, when it was used more than paraquat.[4] Non-agricultural use includes domestic use, turf, golf courses, ornamentals, tree plantations, roads and paths. It is used on lettuce, alfalfa, clover, fruit, nuts, berries, and vineyards. Benfluralin's EU approval expired in 2023,[5] leaving pendimethalin as the only EU-approved dinitroaniline.[6]
Benfluralin is practically non-toxic. Chronic exposure may harm the liver and kidneys. No endocrine disruption is known. EPA modelling puts benfluralin water concentrations below any level of concern, and real life evidence shows benfluralin levels to be lower than predicted. [7]
Benfluralin's soil half-life is moderate, 22-79 days, and volatilises quickly. It can bioaccumulate in fish, to whom it is very toxic. It is practically non-toxic to birds and bees.[7]
After application, benefin must be inforporated into soil. It is usually applied at ~1.2 lb/ac (1.35 kg/Ha) active ingredient.[8]
Benfluralin has been marketed as: benfluralin, benefin, Bonalan, Carpidor, Benefex, Emblem, Balan, balfin, Surflan XL 2G, XL 2G. (XL 2G tradenames also contain oryzalin.)
Benefin controls the following weeds: (non-exhaustive list) Grasses: Annual bluegrass (Poa annua), barnyardgrass / watergrass (Echinochloa crus-galli), crabgrass Digitaria, crowfootgrass (dactyloctenium aegyptium), foxtails / bottlegrass / bristlegrass / pigeongrass (Setaria), Johnsongrass (seedling only) (Sorghum halepense), junglerice (Echinochloa colonum), fall panicum (panicum dichotomiflorum), Texas panicum / buffalograss / coloradograss (panicum texanum) and ryegrass / sandbur (lolium multiflorum). Weeds: carpetweed (Mollugo verticillata), chickweed (stellaria media), florida pusley / purslane / mexican clover (Richardia scabra), knotweed (Polygonum aviculare), common lambsquarters (Chenopodium album), pigweeds (Amaranthus), common purslane (Portulaca oleracea) and redmaids (Calandrinia ciliata).[8]