The first benzoic acids identified as herbicides were
TBA (2,3,6-trichlorobenzoic acid) and TIBA (2,3,5-
triiodobenzoic acid) in the 1940s. TBA controls many
broadleaf weeds and is selective in cereal crops, but it was
primarily used for the nonselective control of deep-rooted
noxious perennial broadleaf plants, including woody vines
and brush. TIBA was used as a general defoliant and as
a growth regulator for certain crops.
