• The Binary Search for Accuracy in Plant Symbols

      Gibbens, R. P.; Bilan, T. N. (Society for Range Management, 1981-05-01)
      The transfer of data from field sheets to computer files always involves the risk of errors being made in plant symbols or other identifying codes. If a master list of symbols or codes is incorporated into the software programs used for data entry on CRT computer terminals the risk of making errors can be substantially reduced. This is done by utilizing the highly time efficient binary search to compare each entered symbol or code with the master list. Detection of errors before the data are transferred to computer files saves much time which would otherwise be spent in retrieving and correcting files.
    • Toxicity and Control of Kelsey Milkvetch

      Cronin, E. H.; Williams, M. C.; Olsen, J. D. (Society for Range Management, 1981-05-01)
      Kelsey milkvetch (Astragalus atropubescens Coult. and Fish.) contains miserotoxin (β-glucoside of 3-nitro-1-propanol). Chemical analyses and biological evaluations indicated moderately low concentrations of the toxin in this species. However, this plant has been implicated in cattle losses and a potential danger of both acute and chronic poisoning exists on grazing areas where kelsey milkvetch grows in abundance. It grows in mountainous areas in the Salmon River drainage in Idaho and the Big Hole River drainage in Montana. Kelsey milkvetch was controlled with an application of 2.24 kg/ha (2 lb/ac) of 2,4,5-T[2,4,5-tricholorophenoxy)acetic acid] and eradicated with an application of silvex [2-(2,4,5-tricholorophenoxy)propionic acid].
    • Translocation and Storage of 14 C-labled Total Nonstructural Carbohydrates in Honey Mesquite

      Fick, W. H.; Sosebee, R. E. (Society for Range Management, 1981-05-01)
      Translocation of total nonstructural carbohydrates (TNC) in mature honey mesquite (Prosopis glandulosa var. glandulosa) trees was studied by photosynthetically incorporating 14 CO2 on eight dates during the summer of 1975. Several plant parts were analyzed for TNC and relative total activity (RTA) to determine direction of translocation and sink strength. Stem and twig TNC fluctuated more than basal bud TNC in response to phenological development. Pods were generally the strongest TNC sink except during initial pod formation (June 25), when bidirectional translocation occurred and all plant parts sampled contained equal concentrations of the 14 C label. A RTA/TNC ratio used in conjunction with RTA and TNC suggested that increased TNC concentrations in the pods and stems may not always be due to increased import of TNC but caused by a reduction in growth with constant importation. Greatest translocation of TNC to the basal buds occurred between the phenological stages of green flower spikes (June 10) and pod formation (June 25) and during pod maturation (August 4 to August 19).
    • White-tailed Deer Diets from Pastures in Excellent and Poor Range Condition

      Bryant, F. C.; Taylor, C. A.; Merrill, L. B. (Society for Range Management, 1981-05-01)
      A study was initiated in August, 1975, to examine the forage available to and diet composition of white-tailed deer on pastures of excellent and poor range condition at the Sonora Research Station near Sonora, Texas. Grass and forb standing crop and deer feeding time on these two forage classes were considerably higher on the pasture in excellent range condition than that in poor range condition. Browse standing crop and feeding time was greater from the pasture in poor range condition. The Merrill 4-pasture grazing system appeared to increase the availability and use by deer of grass regrowth. Yearly averages of crude protein and phosphorus were higher in diet samples collected from the pasture in excellent range condition. Digestible energy levels were similar between pastures when averaged over the 1-year period. Digestible energy levels in diets were, however, higher from the excellent condition pasture in every season except winter. In winter, deer fed primarily on the foliage of oak on excellent condition range; but on the pasture in poor range condition, deer used large amounts of foliage and mast from juniper and dead leaves of persimmon in addition to oak foliage. Juniper and persimmon apparently contributed to the higher digestible energy levels observed on the pasture in poor range condition during the winter season. Energy may be a major nutrient limiting deer production on the Edwards Plateau.