• Genetic Gains and Stability for Germination Salt Tolerance in Alfalfa

      Poteet, David; Robinson, David; Smith, Steve; Dobrenz, Albert; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Improving the germination salt tolerance of alfalfa will help this crop endure both increasingly saline irrigation water and salt build -up in the soil. Seven previous cycles of selection for salt tolerance at germination plus the parental line, Mesa-Sirsa, were evaluated for percentage germination under various levels of NaCI solutions. Germination improved linearly from the earliest to the latest cycle of selection. Germination salt tolerance can be improved through recurrent selection techniques.
    • PEG-Induced Stress on Alfalfa Seedlings

      Ellsworth, Todd; Robinson, David; Dobrenz, Albert; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Performance of Germination Salt Tolerant Alfalfa on a Non-Saline Site

      Smith, Steve; Conta, Debra; Dobrenz, Albert; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
    • Salt Tolerance During Seedling Establishment in Alfalfa

      McKimmie, Tim; Dobrenz, Albert; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      Deposition of salts from irrigation water is an increasing concern for Arizona farmers and agronomists. Selection for salt tolerance during the seedling stage has been undertaken over the past three years. Yield tests were conducted in greenhouses and a significant increase in dry matter production was shown in the selected material.
    • Seedling Alfalfa Root Research

      Reffruschinni, Katie; Robinson, David; Dobrenz, Albert; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      There has been limited research on the rooting patterns of alfalfa. This information would be important in developing new germplasm sources that are more water efficient, salt tolerant and drought tolerant. Ten alfalfa varieties were evaluated for possible genetic control of rooting traits. Seedlings were grown hydroponically in a growth chamber. The cultivars evaluated showed a significant statistical difference for width of lateral root system and number of lateral roots. The variation in seedling rooting patterns is sufficient to warrant a selection program for improved lateral rooting patterns.
    • Stomatal Response to Water Stress in Two Pearl Millet Genotypes

      Osman, Mohamoud; Dobrenz, Albert; Tewolde, Haile; Voigt, Robert; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)
      A study was conducted in the field to test whether stomatal sensitivity to water stress can be used as a selection criterion for drought tolerance in two pearl millet genotypes. In both cultivars, stomatal aperture was significantly reduced by the water stress. However, the proportion of reduction per 20 mm decrease in applied water was much higher for the hybrid than for the female parent. This is clearly an indication of a higher stomatal sensitivity in the hybrid, which probably explains the superior performance under water stress that was previously observed in this genotype.
    • Strain Crossing for Large-Leaflet Alfalfa: A First Look

      Dobrenz, Albert; Robinson, David; Smith, Steve; Ottman, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 1987-09)