• Economics of Tall Larkspur Control

      Nielsen, D. B.; Cronin, E. H. (Society for Range Management, 1977-11-01)
      Tall larkspur (Delphinium barbeyi Huth.) was chemically controlled in the subalpine areas of the Manti Canyon Cattle Grazing Allotment in Central Utah, and the reduction in cattle losses on controlled areas was observed. Without control, an average of 36 mature cattle were lost per year over a 15-year period, and an average of 11 calves were lost per year over an 8-year period. Cost of control ranged from $15-$22 per acre of larkspur for the first application, and from $13-$17 per acre for the second application. Cattle losses were reduced over 90% in the sprayed pastures. Thus, the estimated annual value for adult cattle saved was $8,250 and for saved calves it was $1,200. Internal rates of return ranged from 72.25% to 60%, with the rate dependent upon whether calves saved were included. A return of 10% can be expected from larkspur control if eight to nine cows are saved each year for 10 years.
    • Herbicides, Nitrogen, and Control of Tall Larkspur under Aspen Trees

      Cronin, E. H.; Bowns, J. E.; Johnson, A. E. (Society for Range Management, 1977-11-01)
      Tall larkspur (Delphinium barbeyi Huth.) dominates the herbaceous vegetation under quaking aspen (Populus tremuloides Michx.) on large areas of mountain summer ranges in southern Utah. These tall larkspur plants are more susceptible to single applications of 2,4,5-T and silvex than reported for the same species growing in the open subalpine meadows of central Utah. The herbicide treatments evaluated provide a means of manipulating the vegetation to produce various proportions of grasses and forbs that would be safe and desirable for cattle or for dual use by cattle and sheep. Nitrogen fertilization applied in addition to herbicide treatments did not enhance control of tall larkspur or stimulate forage production. High rates of nitrogen applied to otherwise untreated plots did not control tall larkspur, and increased forage production only the first year after application.