Greenhouse and field studies were conducted to assess the relative tol
erance of leading bell pepper (Capsicum annuum L.) varieties to the he
rbicide bentazon, In the greenhouse, nine bell pepper varieties varied
in bentazon tolerance. One of the most tolerant varieties, 'King Arth
ur', was not severely injured, and its shoot mass was not reduced by 2
.0 kg.ha(-1) bentazon. The shoot mass of one of the least tolerant bel
l varieties, 'Summer Sweet 860', was reduced by 1.0 kg.ha(-1) bentazon
, The bentazon rates resulting in 50 percent reduction in shoot mass (
MR50) or injury (I-50) estimated by logit-prohit analysis were 7.9 and
3.1 kg.ha(-1) for 'King Arthur' and 3.8 and 1.5 kg.ha(-1) for 'Whoppe
r Improved', respectively. In a field study, F-1 'King Arthur', the to
lerant control 'Santaka', and the F-2 progeny of 'King Arthur' were si
milar in bentazon tolerance, and there was no genetic segregation for
tolerance in the F-2 population. Some modern bell pepper varieties app
ear to be sufficiently tolerant to allow bentazon use. Chemical name u
sed: -methylethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2 dioxide (b
entazon).