ECONOMICS OF HERBICIDE CONTROL OF LEAFY SPURGE (EUPHORBIA-ESULA L)

Leafy spurge (Euphorbia esula L.), a widely established exotic, noxiou s, perennial weed, is a major threat to the viability of commercial gr azing and to beneficial outputs of wildlands in the Upper Great Plains . Herbicide treatments are often recommended based upon measures of ph ysical control rather than on economic criteria. A deterministic, bioe conomic model was developed to evaluate the economic viability of curr ent herbicide control strategies for leafy spurge. Control viability i s highly site specific but falls into three categories. First, broadca st herbicide treatment may result in positive net returns for some gra zing situations, especially small infestations on highly productive la nd, in the Upper Great Plains. Second, treating the perimeter to preve nt patch expansion is viable in some situations when treating the enti re infestation is not viable. Finally, for well-established infestatio ns on less-productive land the best alternative, from an individual la ndowner's perspective, is to not treat leafy spurge with herbicide and bear the increasing productivity losses.