Digital Commons Network^™

The Interactions Of Electrical Conductivity, Sodium Adsorption Ratio, Water Volume And Rhizobial Strain On Phaseolus Vulgaris L., David A. Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A greenhouse experiment was conducted to determine the interactive effects of water salinity, volume of water applied at each irrigation, sodium adsorption ratio and rhizobial strain upon 15 plant growth parameters of Phaseolus vulgaris L. Four levels of water salinity (EC_W 0.4, 3.0, 6.0, or 9.0 mmho/cm), three levels of water volume (200, 400, or 800 ml per pot), three levels of SAR (4, 16, or 64) and three strains of Rhizobium phaseoli (K-17, K-47, or K-52) were used. The treatments were replicated with all possible combinations. Data were subjected to analysis of variance, multiple comparisons, and path coefficient …

Fertility And Saline Water Management Interactions On Plant Growth And Nitrogen Fixation In Phaseolus, Robin R. Drysdale Rodriguez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A greenhouse study was conducted involving interactive effects on bean yield of three levels of irrigation water salinity, three frequencies of irrigation water app li cation, two level s of nitrogen, and seven levels of phosphorus fertilization to determine if the effects of adverse saline conditions or water stress could be overcome by fertility and/or saline water management.

Dry matter and bean yields were reduced with decreasing irrigation frequency (2 days to 8 days) and increasing salinity of irrigation water (0.5 mmho/cm to 8.0 mmho/cm). At low salinity levels (0.5 mmho/cm) dry matter production and the number of pods per …

Higher Plant Acclimation To Solar Ultraviolet-B Radiation, Ronald Robberecht

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plant acclimation to natural and intensified solar UV-B irradiance was investigated in three species, Oenothera stricta Ledeb., Rumex obtusifolius L., and R. patientia L. The objectives of this study were to determine: (1) the relationship between plant sensitivity and epidermal UV attenuation, (2) the effect of phenotypic changes in the leaf epidermis, resulting from UV-B exposure, on plant sensitivity to UV radiation, and (3) the plasticity of these changes in the epidermis leading to plant acclimation to UVB radiation.

Epidermal UV transmittance was found to differ in magnitude and spectral distribution among the three species examined in this study. Epidermal …

The Roles Of Mechanical Stress And Ethylene In Clinostat-Induced Leaf Epinasty And Gravitropic Response Of Dicot Shoots, Raymond M. Wheeler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aminoethoxyvinyl glycine (AVG) and silver thiosulfate, antagonists of ethylene biosynthesis and action in plants, both delayed onset of leaf epinasty in Xanthium strumarium L. (cocklebur) plants rotated on horizontal clinostats. Xanthium plants mechanically stressed by continuous horizontal or vertical shaking, or continuous twisting back and forth, did not develop any significant epinasty, while plants inverted every 20 minutes (upside down half the time) did develop epinasty. From this it appears that clinostat-induced epinasty is a result of gravity compensation rather than mechanical stress.

Treatment of Xanthium, Lycopersicon esculentum Mill. (tomato), and Ricinus communis L. (castor bean) …

Fall Regrowth Of Crested Wheatgrass And Fourwing Saltbush, Noor Mohammad

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

During 1980-81, studies with crested wheatgrass (Agropyron desertorum) and fourwing saltbush (Atriplex canescens) were conducted in controlled environment growth chambers as well as under field conditions to achieve the following objectives:

1. To determine the effect of nitrogen fertilizer on the water use efficiency.

2. To determine the effects of various temperature, water stress and nitrogen treatments on the productivity, nitrogen content and carbohydrate reserves.

3. To determine the effects of N fertilization on fall and spring regrowth.

Crested wheatgrass and fourwing saltbush plants were maintained in three growth chambers for 60 days under three temperature …

Effect Of Mild Water Stress And Enhanced Ultraviolet-B Irradiation On Leaf Growth Of Rumex Obtusifolius L. And Rumex Patientia L. (Polygonaceae)., Steve R. Holman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Leaves of Rumex obtusifolius L. and R. patientia L.were exposed to combinations of mild water stress and enhanced ultraviolet-B irradiation during their ontogeny. Two UV-B treatments (enhanced UV-B and control) and three water stress treatments (-0.0 MPa, -0.2 MPa and -0.4 MPa rooting medium matric potentials) were employed. The impact of the stress interaction was assessed on the basis of changes in leaf area, average adaxial epidermal cell size, and total number of adaxial epidermal cells per leaf. Although the level of UV-B irradiation applied was insufficient to significantly alter leaf growth at any given water stress, UV-B did interact …

The Energy Expenditure Of Heifers Grazing Crested Wheatgrass Rangeland In West-Central Utah, Kris M. Havstad

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The free-roaming ruminant requires energy for the demands of vii grazing, traveling and thermoregulation that are not required by its confined counterpart. Literature estimates of these additional costs range from 10 to 170 percent above maintenance. The uncertain magnitude of this increased demand and the factors that contribute to it impede the ability of the rangeland ruminant nutritionist to establish guidelines for the energy requirements of the free-roaming herbivore. This study was designed to estimate the energy expenditure of yearling Angus heifers while grazing a declining supply of available crested wheatgrass forage (Agropyron cristatum) on rangeland in west-central …

Some Morphological And Chemical Responses Of Blackbrush (Coleogyne Ramosissima) To Goat Browsing: Influences On Dietary Blackbrush Selection By Goats And Cattle, Frederick D. Provenza

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Domestic goats were used to modify the growth form of blackbrush, a spinescent shrub occurring in nearly monospecific stands on several million hectares of rangeland in the southwestern United States. The objective of this research was to evaluate goat browsing as a means of improving these rangelands for cattle. Winter goat browsing stimulated spring twig growth from basal and axillary buds which resulted in increased production.

Twig production by heavily browsed plants (>95 percent removal of current season's twigs) was a function of precipitation, soil depth, branch location on the plant, and period of rest after browsing. As precipitation …

Natural Pastures Of The Macquarie Region Of New South Wales: Their Origin, Composition And Management, David Leslie Michaelk

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two experiments were conducted in the semi-arid (400 millimeter annual rainfall) Macquarie region of New South Wales, Australia, at the Trangie Agricultural Research Station (31° 59'S; 147° S7'E), to examine (a) the way botanical parameters can be used to separate grazing and climatic impacts on range vegetation, and (b) how this delineation affects application of range science tenets (site, condition and trend) to different pasture types.

Two range sites were studied: Site 1, a light soil type, was dominated by annual grasses, legumes and forbs, whereas perennial grasses (mainly Chloris acieularis and Chloris truncata) dominated the heavy soils of …