• Spraying Tarweed Infestations on Ranges Newly Seeded to Grass

      Hull, A. C. (Society for Range Management, 1971-03-01)
      A high elevation, tarweed-infested range which had been newly seeded to grass was sprayed with 3 rates of 2,4-D at 2 growth stages of the seeded grass. 2,4-D at 0.5 lb./acre killed over 97% of the tarweed and 1 and 2 pounds killed 99 and almost 100, respectively. Rate of spraying when grasses had 1 to 2 leaves did not affect numbers of grass plants but killed more tarweed than did spraying when grasses had 2 to 4 leaves.
    • Thermal Regulation of Water Uptake by Germinating Honey Mesquite Seeds

      Scifres, C. J.; Brock, J. H. (Society for Range Management, 1971-03-01)
      Ambient temperature regulated the rate and extent of water imbibition by germinating honey mesquite (Prosopis glandulosa Torr., var. glandulosa) seeds. Honey mesquite seeds required less water and less time for germination at 85 than at 100 or 70 F. Seeds at 70 F contained almost 3 times as much water as seeds at 85 F when germination first occurred although the rate of water uptake (mg/seed/hr) was reduced considerably. Decreasing moisture availability to 8 atm influenced the rate of water absorption by seeds more at 85 and 100 F than at 70 F.
    • Timing Use of Cool- and Warm-Season Grasses on Pine Ranges

      Pearson, H. A.; Mann, J. F.; Howard, D. A. (Society for Range Management, 1971-03-01)
      A 3-pasture rest-rotation grazing system based on plant growth and development during 2 annual precipitation periods resulted in more equitable utilization of cool- and warm-season grasses (Arizona fescue and mountain muhly) on ponderosa pine range. Plant and cattle productivity were maintained and utilization of forage species was more uniform./El presente estudio se llevó a cabo en un tipo de vegetación de pino ponderosa (Pinus ponderosa) cerca de Flagstaff, Arizona, E.U.A. Los pastos de esta zona se caracterizan por una mezcla de zacates de verano e invierno. Esto dificulta el pastoreo uniforme de las especies debido a la mezcla. Este estudio significó que con un sistema de rotación con tres potreros se obtuvo mas uniformidad de pastoreo de los diferentes zacates. Las épocas de pastoreo y descanso fueron conforme a las épocas de crecimiento relacionadas a las épocas de precipitación.