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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.
321

Low Maintenance Overseed Trials 2007– 2008

Kopec, David M., Gilbert, Jeff J., Pessarakli, Mohammed, Nolan, Steve 02 1900 (has links)
Five hybrid ryegrasses were evaluated as low maintenance turfs against Gulf annual ryegrass an one turf-type perennial ryegrass, when mowed once a week at 2.75 inches. Among four improved hybrid ryegrass entries, several hybrid ryegrass entries did not statistically differ from the dark perennial ryegrass color as hybrid 05 ABL maintained dark color throughout the test from November 2007, to late April 2008. The entries 05 ABD, 04-1 LH and 04-2 LH all provided nominally dark color turfs, which held good color even up to the end of April. At a seed rate of 625 lbs PLS/acre, all entries produced acceptable "dense" turfs, with the exception of Gulf annual. The hybrids 05 ABL and 04-2 LH produced very dense turfs, with high apparent shoot densities very similar to that of perennial ryegrass. Both 04-1 LH and 0 5 ABD hybrids also produced satisfactory turf densities as well. While the perennial ryegrass "American Star" had very narrow leaves, the hybrid 04 2 LH also had fine leaves throughout the season. Hybrid 05 ABL was also fine textured. After emergence, 04-1 LH hybrid had somewhat wider leaves than some of the other hybrids, but it produced finer leaves shortly afterwards until the close of the test. Measured leaf widths ranged from 1.4 to 2.7 mm in February under peak performance conditions of growth and weather. American Star perennial ryegrass ranked highest for quality on most occasions, but was often included in the same statistical mean performance grouping (within the same LSD value range) with the hybrid entries of 04-2 LH, 04-1LH, 05 ABD, and 05 ABL. Froghair was generally better than Gulf annual in quality, while the check plots (nonoverseeded) showed green up by late April. At mid June, both Gulf annual and Froghair hybrid ryegrass had the least amount of overseed present, but the bermudagrass was not filling in quickly as other hybrids which had more bermudagrass cover present and less straw (from dead overseed) present. This was true for hybrids 05 ABL (41% bermuda: 13% straw), and 04-1 LH (25% bermuda: 11% straw). Therefore, there are hybrid entries which show better transition than Gulf annual, and at the same time produce lesser amounts of lingering necrotic tissue at transition.
322

Assessing the Potential Use of TENACITY (mesotrione) Herbicide For use as a Control Agent for Poa annua In Conjunction With Fall Overseeding of Bermudagrass

Kopec, David M., Gilbert, Jeff J., Nolan, Steve, Pessarakli, Mohammed 02 1900 (has links)
Tenacity herbicide (mesotrione) was evaluated for use as both a pre-emergent and post- emergent herbicide in conjunction with fall overseeding of bermudagrass with perennial ryegrass. Tenacity herbicide, when applied @7 DBOS, 1 DBOS, at first mowing (2 WAOS) or 3 weeks after the first mowing (5 WAOS) did not cause a reduction in stand of perennial ryegrass compared to non-treated controls. There was essentially no difference in ryegrass emergence and cover for Tenacity when applied at the 2.0 oz. versus the 3.0 oz AI/A rate. When applied at these rates at both 7 DBOS and at the first mowing, treatments 1, 3, and 6 produced similar results. Overseeding occurred on October 16, 2007. Intense Poa annua pressure dominated the overseed ryegrass by late December, causing a decline in existing ryegrass cover. Only the latter applied treatments (of Prograss, or tank mixes which contained Prograss with Tenacity) regained sizable amounts of ryegrass by the end of February and early March. Percent weed control was ineffective for treatments which did not include Prograss herbicide. The split application of Prograss of 0.75 lbs AI/a applied @ 8 WAOS and again @ 12 WAOS resulted in the greatest amount of Poa annua control, and the greatest amount of ryegrass. Tenacity (mesotrione), when applied at rates and timings observed here, was safe for perennial ryegrass emergence, but ineffective on Poa annua pre-emergence and as a post emergent agent based on the subsequent growth of Poa annua.
323

Use of Velocity for Post Emergence Control of (AB) in Overseeded Turf

Kopec, David M., Gilbert, Jeff J., Nolan, Steve, Pessarakli, Mohammed 02 1900 (has links)
Velocity herbicide was applied alone, or with mixtures of Tourney fungicide and/or Primo PGR for the post emergence control/suppression of Poa annua (var. annua) in bermudagrass overseeded with perennial ryegrass. When applied alone as a repeat applications, Velocity herbicide applied at 15 and 30 gm ai/a was safe on perennial ryegrass overseed (based on color response). Velocity was safe for the overseed ryegrass when tank mixed with Tourney fungicide, both with and without the addition of Primo PGR. Tourney fungicide when applied alone at either 8 or 16 oz./product/acre produced no negative affects. As expected, Primo alone produced a dark color turf (7.8, 7.5, 7.0, and 7.0) on all four dates, respectively. Several treatments caused moderate injury to the (AB) across the entire test period. These included Velocity alone at the 15 gm/ai/a rate, and Velocity @ 30 gm ai/a plus Tourney @ 8 oz.prod/acre. The greatest amount of injury to (AB) occurred on 3/11/2008 for Velocity at 30 gm ai/a, either with or without Tourney fungicide. Although visible injury to Poa annua resulted after treatments were applied, seed head suppression was the most consistent treatment response. While injury to the Poa was severe for some treatments (Velocity plus Tourney fungicide), the Poa annua did return, ranging from re-growth as "weak plants" to an actively growing turfs (as is sometimes typical after a surviving injury response). Based on results, perhaps a tank mix application of Velocity at 30 gm ai/a along with 8 oz. product/acre of Tourney and 6 oz./acre of Primo, followed by a repeat application 35 days later may provide the ultimate seed head suppression.
324

Evaluation of Dimension and Barricade for Pre-emergence Control of Poa annua in Overseeded Bermudagrass Turf

Kopec, David M., Gilbert, Jeff J., Nolan, Steve, Pessarakli, Mohammed 02 1900 (has links)
For pre-emergence control of Poa annua (PA), Dimension as the EC and 270 G (granular) formulations were applied either as single applications at 6 and 8 weeks before fall overseeding, followed by sequential applications of Barricade. Barricade was also applied 6 and 8 weeks before overseeding. The plots were overseeded on October 2, 2006 with a Citation III perennial ryegrass blend at the rate of 625 lbs PLS/A. When overseeded with perennial ryegrass: Both pre-emerge treatments of the 270G formulation, and Barricade applied at 0.77 lbs AI/A six weeks before overseed (6WB0S) had moderate to severe stunting. Both Dimension treatments (6 and 8 weeks BOS) had no apparent loss of vigor, and were equal in vigor with that of the non-treated turf. By mid December , the 270G treatments produced the least amount of ryegrass cover. Also on October 18, there was a slight reduction in ryegrass cover for Dimension and Barricade treated turfs. The single application treatments of Dimension produced slight/moderate percent weed control in February and March, which declined rapidly by the end of March. On March 15, Dimension applied at 32 ounces/product/acre at 6 and 8WBOS had a season maximum of 43%, and 20% weed control, respectively. Barricade applied at 0.77 lbs. product/A had the highest amounts of PA control realized in this test. The pre/post application of Barricade (alone) produced percent weed control values statistically similar to that of the single pre-emergence application of Barricade alone at either 6 or 8WBOS. The 270G treatments produced much higher levels of percent (PA) control than the liquid formulation on all three dates. In non-overseeded turf: Liquid Dimension treatments showed NO control whatsoever at 8WBOS. At 6WBOS, 24% PA weed control was the highest control achieved early on at the November 2 evaluation. Barricade, when applied once as a pre-emergence, had good to moderate percent PA weed control, which declined after December (45% in January) at the 6WBOS timing. The 270G treatments had very good initial weed control (as it did on the overseeded plots) with 93–97% weed control on November 2, 89% - 91% on November 17, and 71-80% weed control on December 7. The affect of overseed alone on suppression of PA was 72%, 60%, and 52% (16 Feb, 15 Mar, and 26 Mar).
325

Repeat Applications of Paclobutrazole (TGR) Plant Growth Regulator on Overseeded Bermudagrass Turf: Weed Control and Bermudagrass Transition

Kopec, David M., Gilbert, Jeff J., Pessarakli, Mohammed, Nolan, Steve 02 1900 (has links)
TGR (paclobutrazole) was applied to both overseeded and non-overseeded turfs in repeat monthly applications at either 8.0 oz or 12.0 oz product/1000 ft² rates. Applications were made in repeat monthly intervals to apply either three, four or five repeat applications beginning in December 2007, and ending in April 2008. When applied as a post emergent PGR material, TGR caused only a slight decrease in turfgrass color and quality of overseeded turfs in March at the high (and repeated) rate of 12.0 oz/product/acre. This effect was short lived, as overseeded turfs for the remainder of the season maintained fully acceptable color and quality through the spring transition period. Tenacity turfs always had quality scores of 6.0 or higher throughout the test. Seed head suppression was realized from TGR, with greater head suppression at the 12.0 oz rate than that of the 8.0 oz rate. Bermudagrass transition among TGR treated turfs was not different from that of the untreated controls, whether the turfs were overseeded or not. On 20 June 2008, percent bermudagrass plot cover ranged from 29-58% for TGR treated turfs, 40% for Tenacity, while the overseeded UTC had 35%, on average. The percent bermudagrass increased quickly after a 2.0 lb. /N /M application on June 20, to 68% to 90% bermudagrass cover for TGR treated turfs (UTC = 83%). After a scalping event (from 1.25 inches to 0.50 inches) performed on July 1, percent bermudagrass decreased temporarily (from bermudagrass removal), but rebounded within 15 days to yield 96% to 99% bermudagrass cover by the close of the test on 31 July, 2008. Like wise, Tenacity alone did not inhibit transition, as Tenacity treated turfs had bermudagrass cover slightly greater than that of the overseeded controls.
326

Use of Select Herbicides for Pre and Post Emergence Control of Poa annua When Overseeding Bermudagrass with Perennial Ryegrass

Kopec, David M., Gilbert, Jeff J., Pessarakli, Mohammed, Nolan, Steve 02 1900 (has links)
Overseeding bermudagrass turf with perennial ryegrass is essentially a standard practice in south western turfgrass maintenance. This practice complicates (and often negates) the pre-emergence control of Poa annua (PA) which germinates within the overseeding window. Outplay (mesotrione) was applies as pre , post and pre+post applications to control PA in golf turf (overseed on October 2, 2006). Outplay was applied with Trimmit as a post emergence treatment. Barricade and Barricade + Monument were applied post emergence. On non overseeded turf: The greatest amount of (PA) weed control was achieved by the treatment of Barricade 16 ounce/product/acre (8WBOS) and Monument 16 gm (2WBOS) (Table 3). This treatment had no PA initially (2 November) 93% control on 17 November, and 7 December, 90% control on 4 January, dropping to 77% control by 16 February. Outplay applied pre-emergence as a sole treatment had little or no affect on PA, providing essentially no control. This was even true for the high rate of 16 ounces of product, applied 1 week before overseeding. Outplay applied both pre/post at eight ounces also had little effect on PA. The same was true for Outplay applied as two post emergence treatments [( 8 + 8 ) or (16 + 16) ounce rates] (Table 3). Prograss had a maximum weed control of 50% on January 4, sixteen days after its repeat application of 64 ounce. The post emergence tank mix of Outplay and Trimmit, followed by Trimmit alone had a maximum of 50% (PA) weed control on January 4, which declined afterwards. Overseeded Turf: Barricade and Barricade plus Monument had good control initially (94% 16 February), noting that the addition of Monument increased percent weed control by 10% in March (Table 8). Outplay applied alone as a pre-emergence product, had minimal control, with the high rate of 16 ounces applied 1 week before overseeding providing nominal weed control (65%, 41%, 58%) on 16 February, 15 March, 26 March, respectively. Outplay applied as a post emergence treatment only, exhibited good to moderate weed control, with the 16 and 16 ounce repeat treatments having better weed control than the 8 ounce plus 8 ounce treatments (applied 8 weeks and 12 weeks after overseeding, respectively). The 16 and 16 ounce treatment had 100%, 82% and 78% weed control on 16 February, 15 March, and 26 March, respectively (Table 8). Prograss applied twice as a post emergence provided similar levels of PA control (100%, 85%, 89%) on those same dates, respectively. Finally, when Outplay was applied as a post emergence treatment with Trimmit, weed control was good to moderate, providing 88%, 67%, and 78% weed control on overseeded turfs on 16 February, 15 March, and 26 March, respectively (Table 8). The affect of overseeding itself based on NTC means of overseeding and nonoverseed turfs (no herbicides) showed that overseeding alone suppressed PA by 93% on 16 February, 91% on 15 March and 59% on 26 March.
327

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.
328

Nuotykių parko „lokės pėda“ tvarkymo ir želdinimo ekologiniai principai / Ecological background of the management and ornamental plantation in treetop adveture park „lokės pėda“

Armolaitytė, Rasa 03 January 2011 (has links)
Tyrimų objektas – Jonavos r., netoli nuo azotinių trąšų gamyklos AB „Achema“ Neries upės šlaite įrengtas nuotykių parkas UAB „Lokės pėda“. Tyrimų tikslas – paruošti „Lokės pėda“ parko teritorijos tvarkymo ir želdinimo kultūriniame kraštovaizdyje ekologinius principus. Šiam tikslui pasiekti spręsti tokie uždaviniai: (1) išanalizuoti informaciniai šaltiniai ir mokslinė literatūra; (2) įvertintas oro užterštumas AB „Achema“ teršalais; (3) nustatytas dirvožemių trofiškumas ir degradacija; (4) įvertinta medžių būklė; (5) tirti medynų ir gyvosios dirvožemio dangos pokyčiai. UAB „Lokės pėda“ nuotykių parko, kuris yra tik 1,4 km atstumu į šiaurę nuo AB „Achema“, oras gali būti užterštas NO2 ir NH3 dujomis. Parko šlaite augančiame miške yra vietų, kuriose lankytojai yra sunaikinę dirvožemio žolinę dangą ir miško paklotę. LAMMC Miškų institute atliktos analizės parodė, kad dėl to padidėja dirvožemių viršutinio mineralinio sluoksnio tankis, šis sluoksnis yra užteršiamas sieros junginiais, sumažėja dirvožemio pasotinimas maisto medžiagomis, organine anglimi ir suminiu azotu. Pagal lajų defoliaciją įvertinus šlaito miške medžių būklę, nustatyta, kad parke ir šalia augančiame miške geriausios būklės yra paprastieji klevai ir mažalapės liepos, o paprastieji ąžuolai ir paprastieji uosiai džiūsta. Palyginus su natūraliu mišku, parko trasose ir tarp trasų skirtingų rūšių medžių būklė nėra blogesnė. Tačiau parke yra medžių, kurie turi mechaninius pažeidimus: nubrozdinimus ir neteisingai... [toliau žr. visą tekstą] / The object of research – the treetop adventure park JV „Lokės Pėda“ settled on the slope of river Neris in Jonava district near nitrogen fertilizer plant JV „Achema“. The research aim – to prepare the landscape management and plantation ecological principles in the park. There following objectives were set up: (1) to analyse the informative sources and scientific literature; (2) to evaluate air pollution by emissions from JV “Achema”; (3) to determine soil fertility and degradation; (4) to evaluate tree condition; and (5) to estimate the changes in stand and ground vegetation cover. The treetop adventure park JV „Lokės Pėda“ what is situated only 1.4 km north from JV “Achema”, could be polluted with NO2 and NH3. Thus, in the forest down the park slope there are places where the visitors have destroyed ground vegetation cover and forest litter. According to the obtained research data the bulk density of the uppermost layer of mineral soils is increasing, the topsoil is polluted with sulphur compounds, the soil decreases in saturation of the nutrients, organic carbon and total nitrogen. Evaluating of the tree defoliation down the slope it was estimated, that in the park and the forests close to the park the trees of Acer platanoides and Tilia cordata are in beneficent condition. While, the trees of Quercus robur and Fraxinus excelsior are dying. But if to compare with natural forests, in the park tracks and between the tracks the decline in different tree condition is not... [to full text]
329

Propagation of Coleonema album (Thunb.) Bartl. & J. C. Wendl. : a horticultural and medicinal plant.

Fajinmi, Olufunke Omowumi. 06 November 2013 (has links)
Coleonema album is a South African green treasure, endemic to the Cape region and hard to find in other parts of the country. It is ranked among the most highly utilized medicinal plants at present. The plant extracts exhibit a wide range of pharmacological activities due to its bioactive compounds. Immunat, a tincture from this plant is marketed commercially. Medicinal plant gatherers are on the lookout for this plant due to its high demand and market price. Several natural product companies in South Africa are now exporting Coleonema album oil. Its showy beautiful white flowers make it a valuable ornamental plant. There is no accredited germination protocol available for this medicinal and ornamental plant till date. In this study, the chemical and environmental conditions required for optimum seed germination and seedling growth were studied. The effect of light, temperature shifts, cold and warm stratifications, smoke-water, butenolide, pH levels, plant growth regulators (kinetin, 6-benzyladenine, indole acetic acid and α-Naphthalene acetic acid), salt solutions (sodium chloride and ammonium nitrate) on seed germination were investigated. Seeds showed favourable response of germination at low temperatures (10 and 15 ºC). Seeds exposed to continuous darkness at low temperatures showed highest germination at 15 ºC. Temperature shift (from 20 ºC to 15 ºC) favoured seed germination. pH 6 is the most conducive pH level for Coleonema album seed germination (52.5%). Sodium chloride and ammonium nitrate solutions (pretreatment for 2 weeks) significantly improved germination at a 10-2 M concentration with 62.5 and 75% germination respectively. Coleonema album seeds exhibit a temperature-dependent physiological dormancy. Seed germination of this plant is quite erratic as seed germination started 21 days after incubation and lasted for over 90 days. Germination rate of the seeds is too slow to meet the local and international demand for this plant. Plant tissue culture techniques have been used as an alternative for mass cultivation of plants that are difficult to propagate from seeds. Therefore, an effective micropropagation protocol was developed as a measure to conserve this highly utilized medicinal plant. The effects of the cytokinins: BA, kinetin, TDZ and topolins on in vitro shoot formation of Coleonema album were investigated. Of all the cytokinins tested, 5 μM mT gave the highest number of shoots (14.50) per explant. Combination of 5 μM mT with various concentrations of IBA and NAA significantly increased shoot production. Shoots cultured on IBA supplemented medium produced roots. Root production from NAA cultures is unfavourable as most of the shoots developed callus at the base of the stem. The result of this study has shown that mT has potential as a highly active alternative to BA and other cytokinins for Coleonema album in vitro shoot production. Over 1,000,000 plantlets could be produced annually using the in vitro propagation protocol developed in this study. The results of this study will be useful as a guide for mass cultivation of this ornamental and medicinal plant. It will also provide an opportunity for propagation of Coleonema album in other parts of the country. By virtue of this, the pressure on the wild population of this species could be greatly reduced. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2012.
330

Water use and drought resistance of turfgrass and ornamental landscape plant species

Domenghini, Jacob Cody January 1900 (has links)
Doctor of Philosophy / Department of Horticulture, Forestry, and Recreation Resources / Dale Bremer / Greg Davis / In 2005, turfgrass was estimated to cover approximately 20 million ha of urbanized land. That area is increasing with rapid urbanization, stressing the importance of water conservation in the lawn and landscape industry. Turfgrasses have been identified for replacement by presumably more water-efficient ornamental plant species to conserve water. However, research comparing drought resistance and evapotranspiration (ET) of turfgrasses with ornamental landscape plants is limited. Two studies were conducted to evaluate water use and performance under drought stress of several ornamental and turfgrass species. An online course was developed to educate students about critical water issues related to irrigation in urbanizing watersheds. In a field study, ET was measured using lysimeters and plant water status was evaluated under deficit irrigation (100%, 60%, and 20% ET) in Festuca arundinacea Schreb., Buchloe dactyloides (Nutt.) Engelm. ‘Sharps Improved’, and Ajuga reptans L. ‘Bronze Beauty’. Evapotranspiration was similar between A. reptans and F. arundinacea, and was 32 and 35% greater than ET of B. dactyloides. In a greenhouse study, the performance of one turfgrass (Poa pratensis L. ‘Apollo’) and eight landscape species (Achillea millifolium L., Ajuga reptans L. ‘Bronze Beauty’, Liriope muscari Decne., Pachysandra terminalis Siebold and Zucc., Sedum album L., Thymus serpyllum L., Vinca major L., and Vinca minor L.) was evaluated during a severe dry down and subsequent recovery. S. album, L. muscari, and P. terminalis performed the best, requiring 86 to 254 d to decline to a quality rating of one (1-9 scale: 1=dead/dormant, 9=best quality). The remaining species required 52 to 63 d. The only species to recover were P. pratensis [46% pot cover (PC) after 60 days], S. album (38% PC), and V. major (35% PC). A survey was developed to measure student learning as it relates to the level of sense and meaning present in the content of a new online course entitled “Water Issues in the Lawn and Landscape.” Survey results were compared with student learning as measured through a post-test. Post-test scores declined as the difference between sense and meaning increased (r =-0.82; P=0.03), indicating student learning is higher when both sense and meaning are present.

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