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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Evaluation of Legacy (SP5075) For Post Emergence Control of Annual Bluegrass In Overseeded Bermudagrass Turf: Weed Control and Turfgrass Performance

Kopec, David M., Gilbert, Jeff J., Pessarakli, Mohammed, Nolan, Steve 02 1900 (has links)
SP 5075 (now commercially available as "Legacy" was evaluated as a post emergence herbicide on both non-overseeded and overseeded Tifway bermudagrass turf. From October 2007, to April 2008, monthly application rates of Legacy (alone) were applied at SP5075 @ 14.7 oz/product/acre, 22.1 oz/product/acre and at 29.4 oz/product/acre, along with SP5075 @ 14.7 oz/product/acre & Cutless @ 8.0 oz/product/acre, Primo Maxx alone at 22 oz/product/acre, and Cutless alone at 16 oz/product/acre. Chemical product applications did not affect emergence and treatments containing the formulated product of Legacy showed no inhibition. All treatments had enhanced turfgrass color over the UTC (untreated control) throughout all eight months of the test. The high rate of Legacy exhibited a brief decrease in density, color and quality form late November and into December. The high rate of Legacy produced the least amount of Poa annua cover, the greatest unmowed height suppression, the greatest seed head suppression and vegetative weed control of all treatments, and produced the least discontinuous surface. Cutless alone produced similar turf and Poa annua effects as the tank mix of Legacy at the low rate plus the inclusion of Cutless at 8.0 oz /prod/acre. The high rate of Legacy did not eliminate flowering, but postponed flowering of Poa annua well past the flushes of the UTC, noting that there was much less Poa annua present from this treatment when overseeded. Primo Maxx alone caused minimal seed head suppression of Poa annua, and minimal weed control of total Poa cover and seed heads. Best estimates of transition occurred on 30 June 2008, were treated overseeded turfs ranged from 58% to 80% bermudagrass cover, with 80% cover for Primo alone, with Cutless alone having 58% bermudagrass (UTC = 84%). Since the medium rate of Legacy produced similar Poa activity effects with better turf quality after overseeding (but then decreased in Poa activity afterwards), applications of the medium rate from initial overseed followed by subsequent applications at the high rate starting in January should be investigated for economic, turf performance and weed control performance.
42

Air-layering as a Method of Asexual Propagation of Mesquite

Hagen, R. H., Palzkill, D. A. January 1989 (has links)
Three 12-year-old Prosopis chilensis were successfully layered in spring and late summer. The best rooting occurred with 1 cm stems treated with either 5,000 or 15,000 ppm IBA. Air-layers treated with IBA had a higher rooting rate and better root quality than untreated air-layers.
43

Ethylene-Induced Flower Bud Abortion in Easter Lily is Inhibited by Silver Thiosulfate

Mason, Michael R., Miller, William B. January 1989 (has links)
Flower bud abortion, or "blasting" was shown to be at least partially caused by treating plants with ethephon, a chemical that releases ethylene. In floricultural greenhouses, ethylene could accumulate to levels that could induce commercially significant levels of flower bud injury. Silver thiosulfate (STS) was shown to be a potent inhibitor of ethephon injury. STS at (1 to 2 mM) could be applied as early as the visible bud stage (approximately 5 to 6 weeks before flowering) without phytotoxic effects. Using current silver prices, the material cost for our treatment is less than 0.4 cents per plant. Based on these results, a preventative STS application could potentially reduce much of the flower bud abortion seen in commercial greenhouses.
44

Pregermination Treatments and Temperature Requirements for Germination of Mexican Redbud, Evergreen Sumac, and Mealy Sage Seeds

Tipton, J. L. January 1989 (has links)
Scarification and stratification requirements of Mexican redbud and evergreen sumac seeds and the effects of temperature on Mexican redbud evergreen sumac, and mealy sage seed germination were investigated. The maximum predicted germination from a quadratic response surface was 94.9% after 62 minutes scarification and 35 days stratification for Mexican redbud and 59.3% after 52 minutes scarification and 73 days stratification for evergreen sumac. Mexican redbud seeds germinated from 23.8 to 30.5 C, evergreen sumac from 20.8 to 30.6 C, and mealy sage from 20.6 to 34.2 C. Maxium predicted final percent germination and the temperature at which it occurred for Mexican redbud, mealy sage, and evergreen sumac was 104.2 at 27.5 C, 89.8 at 29.2 C, and 42.4 at 22.1 C, respectively
45

Relative Drought Resistance of Desert Willow, Fruitless Mulberry, and Yellow Bells

Tipton, J. L. January 1989 (has links)
Desert willow and yellow bells had a higher capacity to avoid drought than fruitless mulberry under moist conditions, but the reverse was true under dry conditions. Desert willow and yellow bells had a higher tolerance to dehydration than fruitless mulberry, resulting in a higher relative resistance to drought under either moist or dry conditions. Detached leaves from desert willow and yellow bells plants grown under stress restricted water loss better than those grown under no stress. Fruitless mulberry leaves lost water at essentially the same rate regardless of irrigation.
46

The Golf Industry in Arizona: An Economic Summary

Wade, James C., Barkley, David January 1989 (has links)
In 1987, 191 golf facilities in Arizona were surveyed to determine the employment, income, revenues, and expenditures generated by the state's golf course industry. The direct plus indirect employment and income benefits are estimated to be 12,400 jobs and $155 million in wages, respectively.
47

Winter Turf Performance Trials

Kopec, David M., Mancino, Charles F., Ralowicz, Andrew E., Petty, Michael J., Olson, Mark, Moharram, Hisham N. January 1989 (has links)
Overseeding trials were conducted to evaluate the turf-type fitness of cool season grasses for use in the desert when bermudagrass is dormant. Perennial ryegrass, fine fescues, rough stalk bluegrasses and creeping bentgrasses were tested for turfgrass quality, color, percent ground cover and uniformity under a close mowing (3/8 inch) regime. Entries varied significantly from each other once seasonal hard frosts did not recur after January. Certain entries had better turf performance under hot (late spring) conditions. Both commercially available and experimental germplasm were evaluated.
48

Turfgrass Evaluations of Curly Mequitegrass, Hilaria belangeri (Steud.) Nash.

Ralowicz, A. E., Mancino, C. F., Maricic, A., Nelson, D., Kopec, D. M. January 1989 (has links)
Curly mesquitegrass, Hilaria belangeri, is being evaluated for utilization as a desert turf. Experiments were conducted on plant material collected throughout Arizona to: (a) quantify the natural variation in turfgrass qualities in this species; (b) evaluate the field performance of selected plant material to fertilizing and mowing practices; and (c) assess the effects of planting date and seeding rate on seedling establishment. Thirty-four percent of the rated plant material displayed low growing height while 26.9 % of the plant material had short leaf length. Thirty-five and 23.5 % of the rated plant material had acceptable or better than acceptable color ratings and fine leaf width, respectively. In another experiment, nitrogen had no significant effect on plant color, however, increasing nitrogen increased percent ground cover. Percent ground cover also increased as the height of cut increased. Substantial variation was observed in the number of stolons per plant, and high stolon numbers were not associated with high nitrogen levels. Planting time had a significant influence on seedling establishment. Seeding rates also differed significantly in the number of seedlings established per m².
49

Germination of Lehman Lovegrass and Black Grama Under Controlled Environment Conditions

Kopec, D. M., Scott, R., Munda, B. D., Pater, M. J., Mancino, C. F., Ralowicz, A. E. January 1989 (has links)
Mechanical scarification greatly improved the germination of Lehmann Lovegrass seed. Depending on the type and duration of scarification, seed gemzination can be improved from 10 %-12% germination (untreated seed) to over 90% (60-second scarification in a commercial seed scarifier). Black grama is sensitive to both dehulling and dehulling followed by scarification. Unhulled black grama seed should be used for field plantings.
50

Characterization of Amino Acids and Carbohydrates Found in Whitefly Honeydew As the First Step Toward Bioloical Control

Byrne, D. N., Miller, W. B., Stanghellini, M. E. January 1989 (has links)
A Florida strain of sweet potato whitefly, Bemisia tabaci (Gennadius), was found to have an expanded range which includes several new food crops. To determine why, we examined how it processes plant nutrients. The amino acid and carbohydrate content of phloem sap of poinsettia and pumpkin and of honeydew produced by the Florida strain and a strain from Arizona feeding on both plants were analyzed. Poinsettia phloem sap contained 15 amino acids; 14 of these were in pumpkin phloem sap. Almost all the same amino acids were in the honeydews produced by the two strains on the two hosts. Approximately half of the amino acids found in the honeydew were at concentrations which were significantly lower than concentrations in the phloem sap. Honeydew from both hosts contain six additional amino acids. The major one was glutamine which may be used to expel nitrogen. Carbohydrates in phloem sap and honeydew were common transport sugars, like sucrose. Both honeydews contained trehalulose, a disaccharide not previously associated with insects. Both strains processed phloem sap and honeydew from both plants in the same manner, but the Florida strain produced significantly larger quantities of honeydew; it is therefore assumed to process more phloem sap. Since this strain has access to more phloem sap it also has access to more of the amino acids which are in short supply in the phloem sap of some plants allowing it to broaden its range.

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