Graduation date: 1990

Thesis (Ph. D.)--Virginia Polytechnic Institute, 1964. / Typewritten. Vita. Abstract at end. Bibliography: leaves 93-96. Also available via the Internet.

Thesis (Ph. D.) -- Lincoln University, 2007. / Also available via the World Wide Web.

Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains viii, 65 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 54-57).

No-till pasture renovation can increase the quality and forage yield of underproductive pastures. Decreased erosion, lower costs, and less lost grazing time are advantages of no-till renovation compared to conventional renovation. Unwanted vegetation is first controlled with herbicides to decrease competition for introduced orchardgrass. Two field trials were conducted using a split-plot design to compare three seeding methods and two herbicides. An Aerway no-till drill, a Tye double disk drill, and broadcast followed by harrowing were the seeding methods. Paraquat and glyphosate were used to determine herbicide effect on vegetation control. Orchardgrass did not adequately survive at either trial site. However, where some orchardgrass did survive, vegetation control was more important than seeding method. Competition from annual grasses, many germinating after herbicides were applied, was the reason for renovation failure. Herbicide and initial growth for best control. Yield was doubled in the first harvest by the addition of fertilizer. Early spring forage production from poor pastures is usually more than adequate, so the increase from fertilizer is of marginal value unless it is stored for later use. Yield increase did not carry over to the second harvest when it could be better utilized. Later application dates would extend yield increases from certain species if water is available. / Graduation date: 1994

Thesis (Ph. D.)--University of Wisconsin--Madison, 1958. / Typescript. Abstracted in Dissertation abstracts, v. 19 (1958) no. 6, p. 1157-1158. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 126-134).

Thesis (M.S.)--University of Kentucky, 2008. / Title from document title page (viewed on March 18, 2008). Document formatted into pages; contains: viii, 73 p. : ill. (some col.). Includes abstract and vita. Includes bibliographical references (p. 67-72).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Experiments were conducted in the field, greenhouse, and controlled environment chambers to study the effect of environmental factors on tillering, growth, and carbohydrate content of orchardgrass. Tillers of one genotype were studied with several variable factors (light, temperature, moisture,. nitrogen, and/or defoliation) in each of four experiments. Factorial treatment combinations were used in each of the four experiments to study single factors and interactions. Tillering declined to 73 and 26% of normal light when light intensity was reduced in the greenhouse and field, respectively. In the controlled environment chambers, tillering rates were higher with an 18-hour than for a 9-hour day with 3100 F.C. in both chambers. Soluble carbohydrates in the stubble were associated with tillering. There was a marked increase in water soluble carbohydrates as light energy increased up to normal sunlight. Ory matter production was associated with tillering and carbohydrate contents of orchardgrass, factors which increased tillering augmented clipping dry weights. Tillering and foliage growth were much higher when day temperature was 80*F. as compared with 60°F. There was a sharp increase in soluble carbohydrates with low temperature, but at the high temperature carbohydrates did not accumulate as they were apparently utilized for fast growth and tillering. Carbohydrate accumulation per se was not associated with tillering nor yields when temperatures were sub~-optimum for fast growth. Tillering was increased 30% by irrigation. Tillering of orchardgrass plants, defoliated to 1.5, 3, and 6 inches in combination with other treatments, showed increased tillering and dry matter production as defoliation intensities were relaxed. High tillering rates were associated with the magnitude of carbohydrates in orchardgrass stubble. Root development at the end of the experiment was much poorer for intensive defoliation as compared with lax defoliation. Nitrogen stimulated tillering and retarded soluble carbohydrate accumulation in orchardgrass stubbles, Nitrozen stimulated the production of new tissue and nitrogen compounds at the expense of stored carbohydrates in the stubbles. With slow orchardgrass growth under low nitrogen, soluble carbohydrates in the stubble accumulated. There was good evidence that soluble carbohydrates are directly associated with tillering and growth of orchardgrass when factors such as light, nitrogen, and water do not limit growth. Carbohydrate accumulatpeiro nse is not associated with tillering, if any environment growth factor is sub-optimum for tillering and growth. sub-optimum for tillering and growth. / Ph. D.

Three cycles of recurrent restricted phenotypic selection (RRPS) were carried out on two cultivars each of timothy (Phleum pratense L.) and orchardgrass (Dactylis glomerata L.). The selections were conducted at the E. A. Lods Agronomy Research Center of Macdonald Campus of McGill University from 1984 to 1988. Individual plant selections were based on dry matter yields of 25 plants. Within each of 16 grids, the five highest yielding genotypes were selected (i.e. 80 genotypes overall) and allowed to interpollinate. Equal weights of seeds from each of the 80 selected plants were mixed in each cycle. Evaluation trials were carried out in both sward and spaced stand from 1989 to 1993 to assess the effectiveness of selection in improving dry matter yield. Several other morphological and physiological characteristics of cycles were recorded to find possible associated changes. / Three cycles of RRPS were not effective in increasing forage dry matter yields. The lack of response may be due to a narrow genetic base in the source populations and/or the population size under selection may have been too small, resulting in inbreeding depression. Another explanation for the ineffective selection may be non-random pollination among selected plants. The selection for forage yield produced some minor changes in other characteristics. There was a tendency towards increased plant height and circumference in orchardgrass; however, for timothy, height and circumference were reduced by selection. Cycle 3 of Avon orchardgrass was one day later in maturity and there was also a tendency for later maturity for timothy.