Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 6 of 6
Full-Text Articles in Life Sciences
Physiological Regulation Of Cyclic Flowering In Flax, Aurora Salazar Hovland
Physiological Regulation Of Cyclic Flowering In Flax, Aurora Salazar Hovland
Electronic Theses and Dissertations
The flowering pattern of flax (Linum usitatissimum, L.) is cyclic in nature with periods of blossoming separated by periods of rest. To study the regulation of flowering cycles, four experiments were conducted. The first two dealt with nutritional aspects of cyclic flowering by imposing environmental stresses which conceivably might regulate flowering pattern nutritionally. The third and fourth experiments dealt with regulation from hormonal systems and included in vitro regulation of bud growth by growth regulators as well as characterization of endogenous hormonal systems by fluorimetry and bioassays. In the first experiment, the effects of light intensity, temperature, nitrogen and defoliation …
Estimation Of N Availability And No3-N Movement In Soils, Raymond Charles Ward
Estimation Of N Availability And No3-N Movement In Soils, Raymond Charles Ward
Electronic Theses and Dissertations
Objectives of this study were: (a) to evaluate several N soil tests that are used to estimate soil N availability, and (b) to measure the distribution of inorganic N in the soil profile after an application of fertilizer N. Small grain yield response from an application of 17, 34, or 67 kg N/ha was used as the parameter of N availability. These parameters were related to 23 independent variables by use of a step wise multiple regression program. Nitrogen soil tests and climatic factors (rainfall and temperature) were the independent variables involved in the analysis. Nitrogen soil tests included were …
Nitrate Movement In Freezing Or Frozen Soils, Donald G. Moore
Nitrate Movement In Freezing Or Frozen Soils, Donald G. Moore
Electronic Theses and Dissertations
Nitrate movement in freezing and frozen soils was studied in both disturbed and undisturbed soils by laboratory and field investigations. Thermoelectric cooling plates were placed in insulated freezing boxes. Soil cores placed in the freezing boxes were stored, frozen, or thawed at a specific temperature or temperature gradient. Field plots and soils columns reset into the field environment were used to observe migration of either fall- or winter-applied nitrate. Movement of surface applied nitrate was caused by passage of a freezing front through either saturated or unsaturated sand or saturated Vienna loam. The nitrate movement due to freezing was greater …
Tolerance Studies To Wheat Streak Mosaic Virus In Winter And Spring Wheats, Fazal Rahman
Tolerance Studies To Wheat Streak Mosaic Virus In Winter And Spring Wheats, Fazal Rahman
Electronic Theses and Dissertations
Thirty-five winter and fourteen spring wheat varieties were evaluated for their reaction to wheat streak mosaic virus during 1969-1970 and 1970-1971. Plants were mechanically inoculated and the effects of virus were measured, relative to the control plots, in regards to seed yield, protein percentage, plant height, test weight, 1000-seed weight, number of tillers per plant, number of heads per tiller, number of seeds per head, and number of plants in the 2-foot subplot. Varieties were compared visually for their susceptibility to the virus in terms of percentage infection and severity of symptoms. Seed yield, plant height, test weight, 1000-seed weight, …
Recognizability And Reproducibility Of Airphoto Interpreted Landscape Units, Robert Dean Heil
Recognizability And Reproducibility Of Airphoto Interpreted Landscape Units, Robert Dean Heil
Electronic Theses and Dissertations
A physiographic terrain analysis study using the principles of airphoto interpretation was made: (1) to determine the internal homogeneity of airphoto interpreted mapping units, (2) to determine the variability in characteristics among different occurrences of the same mapping unit, and (3) to determine if the units differentiated were sufficiently different to warrant discrimination. The study was conducted in Sedgewick County, Colorado. The study area was comprised of four distinctly different land forms [sic]: a major river and its associated floodplain and terraces; a level to nearly level loamy upland plain; a level to sloping sandy upland plain; and steeply sloping, …
Evidence For The Presence Of Two Nucleases In Barley Tissue And The Influence Of Genotype On Their Properties, Clay G. Johnson
Evidence For The Presence Of Two Nucleases In Barley Tissue And The Influence Of Genotype On Their Properties, Clay G. Johnson
Electronic Theses and Dissertations
Several lines of evidence have shown that genetic variability exists within the barley species (Hordeum vulgare L.) with respect to the kinetics and specificity of yeast ribonucleic acid degradation. Initial efforts demonstrated that ribonuclease (RNase), in the crude soluble protein fraction from the cultivar Dicktoo, was inhibited by KC1 and phosphate. RNase activity was enhanced if heated to 60 C for short periods. In contrast, RNase in the crude soluble protein of the cultivar Tennessee Winter showed no altered response by either KC1 or phosphate. Maximal RNase activity was at pH 5.0 for extracts of both cultivars (0.16 M KC1), …