RESPONSE OF LEADING BELL PEPPER VARIETIES TO BENTAZON HERBICIDE

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).