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1
Johnson, Robert Jean. "Plant growth regulators : an alternative to frequent mowing /". Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA232051.
Testo completoAbstract (sommario):
Thesis (M.S. in Management)--Naval Postgraduate School, June 1990.Thesis Advisor(s): Carrick, Pual M. "June 1990." Description based on signature page. DTIC Identifier(s): Plant growth regulators, growth indicators. Author(s) subject terms: Plant growth regulators, growth indicators. Includes bibliographical references (p. 39-40). Also available online.
2
Soomro, M. H. "The effects of plant parasitic nematodes and plant growth regulators on root growth of graminacious plants". Thesis, University of Reading, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378682.
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3
Nasim, Muhammad. "Response of rice plants to plant growth regulators under saline conditions". Thesis, University of Aberdeen, 2003. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU164162.
Testo completoAbstract (sommario):
Responses of rice to plant growth regulators on germination and seedling growth under NaCl salinity were studied to identify possible means of increasing salinity tolerance. Gibberellic acid (GA) promoted germination processes and a-amylase activity and increased plumule but reduced radicle growth after emergence. GA partitioned more metabolites towards the plumule than the radicle. Chlormequat (CCC) showed no beneficial effects and abscisic acid (ABA) inhibited germination under saline conditions. Overall there was no large difference in the performance of three rice varieties, BR29, IR8 and Pokkali in germination. Artificially aged seeds showed increased sensitivity to salinity and GA produced similar effects on germination of artificially aged rice seeds as on unaged seeds. Seed pre-treatment with GA was as effective in promoting germination under saline conditions as applying GA in the germination media. GA with low Ca promoted germination and plumule growth as well as radicle growth. GA increased plant height and fresh weight of seedlings under saline conditions, however it did not show a large positive effect on rice seedlings. CCC had no beneficial effects on rice seedlings. ABA showed possible beneficial effects on rice seedlings as it reduced Na+ uptake and increased K+ and Ca2+ uptake. GA in combination with ABA appeared to adapt rice plants better to saline conditions. GA in combination with low Ca also promoted rice growth under saline conditions.
4
Oliver, J. F. "The effects of plant growth regulators and plant parasitic nematodes on cereal root growth". Thesis, University of Reading, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233539.
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5
Christensen, Cynthia Lehua Warnock. "The effect of plant growth regulators on the growth of Closterium moniliferum". PDXScholar, 1990. https://pdxscholar.library.pdx.edu/open_access_etds/3968.
Testo completoAbstract (sommario):
Physiologic responses to Gibberellic Acid (GA), I-Naphthalene Acetic Acid (NAA), Benzylaminopurine (BAP), and Abscisic Acid (ABA). suggest that Oosterium monilfferum has the ability to utilize these plant growth factors. The growth promoters NAA and GA both increased growth when added to the media. The cell division regulator BAP (a synthetic cytokinin). also had a promotive effect on growth. Abscisic acid was found to be inhibitive to growth.
6
Fuentes, Hector David. "Studies in the use of plant growth regulators on phytoremediation /". View thesis View thesis, 2001. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030505.150607/index.html.
Testo completoAbstract (sommario):
Thesis (Ph.D.) -- University of Western Sydney, Macarthur, 2001.A thesis presented to the University of Western Sydney, in partial fulfillment of the requirements for the degree of Doctor of Philosophy, December, 2001. Bibliography : leaves 163-173.
7
Temple-Smith, Kay Elizabeth. "The mode of action of novel plant growth regulators". Thesis, University of Bristol, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317880.
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8
Norton, E. R., L. J. Clark, H. Borrego e Bryan Ellsworth. "Evaluation of Two Plant Growth Regulators from LT Biosysn". College of Agriculture, University of Arizona (Tucson, AZ), 2005. http://hdl.handle.net/10150/198160.
Testo completoAbstract (sommario):
A single field study was conducted during the 2004 cotton growing season at the University of Arizona Safford Agricultural Center to evaluate the effect of two plant growth regulators (PGRs) manufactured by LT Biosyn Inc. on the growth, development, yield, and fiber quality of cotton grown in the southeastern region of the state. This test was designed as a follow up study to work that was performed in 2003 on a grower cooperator site that demonstrated positive lint yield responses to the use of one of the PGRs used in this project. This was an eight treatment test involving the application of two PGRs, HappyGroTM (HG) and MegaGroTM (MG). The two formulations are intended to have different effects on plant growth and development. The HG formulation is a kinetin based product designed to enhance cell division and differentiation. The MG formulation is designed to enhance root growth early in the season. Several treatment combinations were designed to investigate varying scenarios of application of these two products alone and in conjunction with each other. The test included a control and each treatment was replicated four times in a randomized complete block design. Plant measurements were collected throughout the season to look for differences in plant growth and development. Lint yield was estimated by harvesting the entire plot and weighing the seedcotton with a weigh wagon equipped with load cells. Sub samples were collected for fiber quality and percent lint determinations. Plant measurements revealed extremely high fruit retention levels throughout the entire season with end of season levels near 75%. This high fruit retention resulted in very low vigor. Under these conditions, while lint yield was extremely high for this region (1300-1600 lbs. lint per acre), no statistical differences were observed among treatments. Fiber quality measurements also revealed no significant differences.
9
Fuentes, Hector D., of Western Sydney Hawkesbury University, of Science Technology and Environment College e of Science Food and Horticulture School. "Studies in the use of plant growth regulators on phytoremediation". THESIS_CSTE_SFH_Fuentes_H.xml, 2001. http://handle.uws.edu.au:8081/1959.7/112.
Testo completoAbstract (sommario):
Phytoremediation is a relatively new technology that uses plants for the clean up of contaminated soils.Its low cost, simplicity and environmentally friendly approach make this technology a viable option for remediation but the main drawback is that it must be considered as long term alternative given its slow speed. This work is the first to report the use of Plant Growth Regulators(PGR)to enhance the performance of phytoremediation so that less time is needed for remediation.Soil samples were taken from a heavy metal contaminated, abandoned mine site for plant growth trials. A clean soil was also analysed and used for reference.Trials were carried out by growing corn in the contaminated soils and using various concentrations of IBA and NAA together with soil amedments to see if these could increase the accumulation of Zn, Mn, Cu, Bb and Fe in corn. Several further tests were conducted and results noted.Doctor of Philosophy (PhD)
10
Tickes, B., e M. J. Ottman. "Evaluation of Plant Growth Regulators on Wheat in Arizona, 1987". College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/200841.
Testo completoAbstract (sommario):
Plant growth regulators are applied to small grains to decrease lodging which can adversely affect crop growth and yield. Wheat is intensively managed in Arizona, and lodging can be a problem. Chlormequat and ethephon were applied at various rates and times in six studies in 1987 to evaluate their use on Arizona's semi -dwarf cultivars with respect to lodging plant height, yield components and grain yield The results indicated that growth regulators applied at the recommended rates and times may decrease plant height and decrease kernel weight. However, the influence of growth regulator treatments on tiller number, head number, kernel number, and grain yield was not demonstrated. The ambiguous results obtained suggest our efforts need to be directed toward documenting the extent of lodging in the state, studying the effects of lodging and predicting when lodging will occur.
11
Hay, Elizabeth Irene. "Somatic embryo development and phenotypic variation in an abscisic acid-independent line of Larix x eurolepis". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0028/NQ32748.pdf.
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12
Attaha, Ali H. Mohamad. "Effects of some plant growth regulators on productivity of strawberries". Thesis, University of Manchester, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252892.
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13
Helps, I. M. "The synthesis of plant growth regulators via alkyne hexacarbonyldicobalt complexes". Thesis, University of Strathclyde, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381126.
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14
Sheridan, Norman P. "The interaction of plant growth regulators with cell membrane constituents". Thesis, Kingston University, 1986. http://eprints.kingston.ac.uk/20346/.
Testo completoAbstract (sommario):
The thesis describes the interaction of auxins with membrane fractions prepared from etiolated epicotyl tissue of ‘Pisum Sativum’ seedling. The interaction of auxins with phospholipids was also examined. Two classes of high affinity binding tissue sites were found in the growing region of the epicotyl tissue. Kinetic analysis of the data resulted in dissociation constant values of: K[sub]1=2.2x 10[sup]-7 M, n[sub]1=1.8x10[sup]-10 moles/g fresh wt; K[sub]2=11x10[sup]-7M, n[sub]2=3x10[sup]-10 moles/g fresh wt. These sites were not found in the non-growing region of the pea epicotyl suggesting that they may be involved in the growth process. From the competition studies reported here, it would appear that site 2 showed greater auxin specificity than site 1 and this could be considered a candidate as an auxin receptor. Sucrose gradient fractionation techniques were employed to further separate the two binding sites and it was shown that site 2 binding was associated with fractions rich in plasma membrane while site 1 was associated with the endoplasmic reticulum. Separation of the solubilized sites by gel permeation methods indicated an apparent molecular weight of 42,000 daltons. IAA was shown to complex with the polar head group region of phospholipids, in CDCl[sub]3, although the strength of the complex was rather low (Kd=1.9x10[sup]-2 Molal). The strength of binding was influenced by the polar head groups of the phospholipids, but did not appear to be affected by the fatty acyl chain length. The physiological significances of such interactions are discussed.
15
Magnitskiy, Stanislav V. "Controlling seedling height by treating seeds with plant growth regulators". Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1101741472.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Ohio State University, 2004.Title from first page of PDF file. Document formatted into pages; contains xix, 157 p.; also includes graphics. Includes bibliographical references (p. 147-157).
16
Augustyn-Gradkowska, E. "Stereocontrolled synthesis of plant growth regulators, abscisic acid and xanthoxin". Thesis, London Metropolitan University, 1985. http://repository.londonmet.ac.uk/3314/.
Testo completoAbstract (sommario):
The project is concerned with the total synthesis of plant growth regulators related to abscisic acid (ABA). The biological activity of these plant growth regulators, ABA and Xanthoxin, and their derivatives is influenced by the stereochemistry of the double bond system in the side chain, the 2Z,4E-isomers being most potent.
17
Zhang, Xunzhong. "Influence of Plant Growth Regulators on Turfgrass Growth, Antioxidant Status, and Drought Tolerance". Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30739.
Testo completoAbstract (sommario):
A series of studies were conducted to examine the antioxidant status, drought and disease tolerance, and growth response to foliar application of soluble seaweed (Ascophyllum nodosum) extracts (SE) and humic acid (HA; 25% active HA or 2.9% active HA) in tall fescue (Festuca arundinacea Schreb), Kentucky bluegrass (Poa pratensis L.) and creeping bentgrass (Agrostis palusttis Huds.) grown under low (-0.5 MPa) and high (-0.03 MPa) soil moisture environments.
Foliar application of humic acid (2.9 % active HA) at 23.7 and 47.4 l/ha improved leaf water status, shoot and root development in tall fescue, Kentucky bluegrass and creeping bentgrass grown under drought. Humic acid (2.9% active HA) at 15.5 l/ha or SE at 326 g/ha significantly reduced dollarspot incidence and improved turf quality in creeping bentgrass.
Drought stress induced an increase of antioxidants alpha-tocopherol and ascorbic acid concentrations in the three turfgrass species. In the experiment with Kentucky bluegrass, drought stress increased beta-carotene concentration, but did not significantly influence superoxide dismutase (SOD) activity.
Foliar application of humic acid (25% active HA) at 5 l/ha and/or SE at 326 g/ha consistently enhanced alpha-tocopherol and ascorbic acid concentrations, leaf water status, and growth in the three cool-season turfgrass species grown under low and high soil moisture environments. In the experiment with Kentucky bluegrass, application of HA at 5 l/ha plus SE at 326 g/ha also increased beta-carotene content and SOD activity under low and high soil moisture environments. There were close positive correlations between the antioxidant status and shoot or root growth in the three turfgrass species regardless of soil moisture levels.
The antioxidant SOD activity, photosynthetic capacity in terms of Fvm690, and chlorophyll content in terms of Fm730/Fm690 exhibited a seasonal fluctuation in endophyte [Neotiphodium coenophialum (Morgan Jones and Gams) Glenn, Bacon, Price and Hanlin] -free and endophyte-infected tall fescue. Application of SE enhanced SOD activity, photosynthetic capacity, and chlorophyll content in tall fescue, especially at 4 weeks after SE treatment. The SOD activity, photosynthetic capacity and chlorophyll content were not significantly influenced by the endophyte infection. A close positive correlation between SOD and photosynthetic capacity during the summer was found in endophyte-free and endophyte-infected tall fescue.Ph. D.
18
Deveson, M. R. "Effects of plant growth regulators on root growth and root/shoot integration in wheat (Triticum aestivum L.)". Thesis, University of Reading, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376235.
Testo completo
19
McCoy, Mark Christopher. "The effects of phytohormones on growth and artemisinin production in hairy root cultures of artemisia annua l". Link to electronic thesis, 2003. http://www.wpi.edu/Pubs/ETD/Available/etd-0529103-162012/.
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20
Guan, Ming. "Steroids in plant development : effects and possible role of brassinosteroids and estrogens". Thesis, University of Exeter, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328469.
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21
Bass, Peter R. "Purification of an enzyme involved in abscisic acid biosynthesis". Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385939.
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22
Castellaro, Simon John. "Aspects of the chemistry and biosynthesis of gibberellins". Thesis, University of Bristol, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329885.
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23
Feys, Bart Julienne Frans. "Towards positional cloning of COI1, an arabidopsis gene controlling the response to coronatine and methyl jasmonate". Thesis, University of East Anglia, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317974.
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24
Lombard, Petrus Johannes. "A biochemical study of budbreak and plant growth regulators in table grapes". Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52617.
Testo completoAbstract (sommario):
Thesis (MSc)--Stellenbosch University, 2002.ENGLISH ABSTRACT: The cultivation of table grapes in the warmer areas of South Africa, indeed worldwide, is complicated by rest breaking problems in spring due to delayed budbreak. In order to overcome these problems rest breaking agents, mainly hydrogen cyanamide, are applied. However, instead of alleviating the problem, additional problems such as uneven budbreak and reduced production are often induced. This study was initiated to further understand the physiological processes occurring during budbreak and how the application of hydrogen cyanamide influences these processes. The following aspects were investigated in this study: a. The effect of hydrogen cyanamide on tissue cytokinin (specifically zeatin riboside) levels of Sultanina table grape vines after application at different times before natural budbreak was studied over two seasons. In 1997, hydrogen cyanamide was applied at three weeks before induced budbreak and in 1998 at six weeks before induced budbreak. One year-old canes were sampled weekly after hydrogen cyanamide application, divided into distal and proximal sections, then further divided into buds, bark and wood tissues and the zeatin riboside (ZR) levels determined. A relatively high amount of chilling coupled to late hydrogen cyanamide application in 1997 led to a large effect on ZR release, but did not lead to significant shifting of the budbreak pattern. Zeatin riboside peaks were observed in buds, internode wood and bark of treated vines compared to control vines. The peaks were higher in distal portions compared to proximal portions in all tissues. The relatively lower chilling and earlier application of hydrogen cyanamide in 1998 had a larger effect on the budbreak pattern while the bud ZR peak was shifted earlier. The distal portion bud ZR . peak was again higher than the proximal portion bud ZR peak. In 1997, as sampling was not initiated early enough, bud ZR peaks were only observed after budbreak, while in 1998 bud ZR peaks were observed before and after budbreak. The effect of these ZR increases on the development of inflorescence primordia, subsequent bunch development and ultimately production, are discussed. b. Free xylem sap was sampled at cane and spur pruned lengths from unpruned canes of Sultanina from budswell until after budbreak in 1999 and from three table grape cultivars, i.e Sultanina, Alphonse Lavalleé and Sunred Seedless, in 2001 and ZR levels determined. The ZR levels in the buds of these three table grape cultivars, pruned to different cane lengths were also determined. One year old canes of these cultivars, were each pruned to long canes (14 buds) and short spurs (2 buds). The ZR content in buds of these canes at distal and proximal positions were determined weekly from budswell until after budbreak in 1999. Xylary ZR peaks occurred before 50% budbreak. Spur xylary ZR levels of all three cultivars followed a similar pattern, although at lower ZR levels than that of the canes. This is similar to previous studies on xylary ZR levels of apple shoots. The high levels of free ZR found in xylem sap at the distal portions of canes support the hypothesis of a cumulative ZR build-up effect as cane length increases. Spur pruning resulted in earlier budbreak and a higher final budbreak than cane pruning. The proximal portions of shoots, whether spur pruned or the proximal portions of canes, showed elevated ZR levels in all cultivars. This difference in ZR levels in bud tissue of different portions of the cane would suggest a difference in ZR consumption or turnover. The results of this study have important management implications for the cultivation of vines in warmer areas in which hydrogen cyanamide is used to alleviate budbreak problems.
AFRIKAANSE OPSOMMING: Die verbouing van tafeldruiwe in die warmer gebiede van Suid-Afrika, soos straks wêreldwyd, word bemoeilik deur rusbreekprobleme in die lente weens vertraagde bot. Rusbreekmiddels, meestal waterstofsiaanamied, word gevolglik toegedien om hierdie probleme te probeer oorkom. In plaas van opheffing van die probleem, veroorsaak hierdie toedienings somtyds addisionele probleme soos ongelyke bot en verlaagde produksie. Hierdie studie is aangepak om die fisiologiese prosesse wat tydens bot plaasvind, beter te verstaan, asook hoe die toediening van waterstofsiaanamied hierdie prosesse beïnvloed. Die volgende is in hierdie studie ondersoek: a. Die invloed van waterstofsiaanamied op lootweefsel sitokinien (naamlik zeatin ribosied, ZR) vlakke van 'n Sultanina tafeldruif wingerd is oor twee seisoene ondersoek na toediening op verskillende tye voor bot. Waterstofsiaanamied is in 1997 drie weke en in 1998 ses weke voor geïnduseerde bot toegedien. Een jaar oue lote is weekliks gemonster na waterstofsiaanamied toediening, verdeel in apikale en basale gedeeltes en verder verdeel in ogies, bas en houtweefsel en die ZR vlakke bepaal. Relatief hoër vlakke koue, gekoppel met later watersiaanamied toediening het in 1997 tot 'n groot effek op ZR vlakke gelei, maar het nie die botpatroon wesentlik verskuif nie. Zeatin ribosied pieke is waargeneem in ogies, internode hout en bas van behandelde wingerd in vergelyking met kontrole wingerd. Die pieke was hoër in apikale gedeeltes in vergelyking met basale gedeeltes in alle weefsels. Die relatief laer koue en vroeër toediening van waterstofsiaanamied in 1998 het 'n groter effek op die botpatroon gehad, terwyl die ogie ZR piek vroeër geskuif is. Die apikale gedeelte se ogie ZR piek was weereens hoër as die basale gedeelte se ogie ZR piek. Monstering was nie vroeg genoeg begin in 1997 nie, aangesien ogie ZR pieke slegs na bot waargeneem is, terwylogie ZR pieke in 1998 voor en na bot waargeneem is. Die effek van hierdie verhoging in ZR vlakke op die ontwikkeling van blom primordia, daaropvolgende tros ontwikkeling en uiteindelik produksie, is bespreek. b. Vry xileemsap is gemonster van langdraer en kortdraer gedeeltes van ongesnoeide lote van Sultanina vanaf ogieswel tot na bot in 1999 en vanaf drie tafeldruif kultivars, naamlik Sultanina, Alphonse lavalleé en Sunred Seedless, in 2001 en die ZR vlakke bepaal. Die ZR vlakke van ogies van hierdie drie kultivars, gesnoei tot verskillende lootlengtes is ook bepaal. Eenjarige lote van hierdie kultivars is gesnoei tot langdraers (14 ogies) en kortdraers (2 ogies). Die ZR vlakke in ogies geleë op apikale en basale gedeeltes van hierdie lote is weekliks in 1999 bepaal vanaf ogieswel tot na bot Xileemsap ZR pieke is waargeneem voor 50% bot. Kortdraer xileemsap ZR vlakke het 'n soortgelyke patroon as die langdraers gevolg vir al drie kultivars, alhoewel teen laer ZR vlakke as die langdraers. Hierdie waarneming is soortgelyk aan vorige studies op xileemsap ZR vlakke van appel lote. Die hoë ZR vlakke gevind in die xileemsap van die apikale gedeeltes van lote ondersteun die hipotese van 'n kumulatiewe opbou van ZR soos die lengte van die loot toeneem. Die snoei van lote as kortdraers het gelei tot vroeër bot en 'n hoër finale bot persentasie as die snoei van langdraers. Die basale gedeeltes van lote het verhoogde ZR vlakke in al drie kultivars getoon, onafhanklik van die feit dat dit vanaf die kortdraer of die basale gedeelte van 'n langdraer was. Hierdie verskil in ZR vlakke in ogie weefsel van verskillende gedeeltes van die loot impliseer 'n verskil in ZR verbruik of omset. The resultate van hierdie studie het belangrike bestuursimplikasies vir die verbouing van wingerd in warmer gebiede, waar waterstofsiaanamied gebruik word om botprobleme te oorkom.
25
Tunio, Shamsuddin. "Effect on environment and plant growth regulators on the growth of different wheat genotypes". Thesis, Bangor University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293125.
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Alghamdi, Mohammed A. M. "Plant growth regulators effects on vegative growth, yield and yield components in winter wheat". Thesis, University of Reading, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553077.
Testo completoAbstract (sommario):
Three glasshouse experiments and one field experiment were carried out to investigate the effect of the plant growth regulator on vegetative growth and yield components of reduced height isogenic lines of the wheat (Triticum aestivum L.) cultivar Mercia. The first experiment compared the growth regulator response of seven isogenic lines of Mercia. Subsequent experiments used four lines, (Mercia control, Rhtl Rht2, and Rht8). Two glasshouse experiments examined the responses under well watered and water stress conditions. The third glasshouse experiment examined rates and time of application under well watered conditions, whilst the field experiment had different rates of application. In all experiments growth regulators reduced plant height significantly in all lines. Growth regulator decreased total dry matter and grain yield with greatest reduction generally for the control and Rht8 lines. Rhtl was the least affected. There were few significant effects of growth regulator on gas exchange and chlorophyll fluorescence but the trend was for greater values with growth regulator. In the first glasshouse experiment, a rate of 2.0 1 ha-1 applied just before the third node detectable stage under non water stressed and water stressed conditions gave slight increases in yield of up to 14% except for line Rht10 which increased significantly in non-stressed conditions. In the second glasshouse experiment, a rate of 2.5 1 ha" applied at the start of stem elongation under 30% FC and 100% FC gave reductions in yield up to 16% for the growth regulator and 55% under water stress. In the field experiment, rates of 2.5 and 3.0 1 ha-1 applied at the start of stem elongation gave reductions in yield up to 20% mainly through individual seed weight. In the final glasshouse experiment, rates of 2.5 and 3.0 1 ha-l applied at 6 leaves unfolded and 1st node detectable both reduced grain yield.
27
Dhansay, Mohamed Afzal. "Synthesis and metal binding properties of selected organophosphorus plant growth regulators". Thesis, University of Cape Town, 1992. http://hdl.handle.net/11427/23201.
Testo completo
28
Puglisi, Sadie Erica. "Use of Plant Growth Regulators to Increase Branching of Clematis Spp". Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/35000.
Testo completoAbstract (sommario):
Clematis spp. L. is a twining vine covered in showy blooms. Typical growth of hybrids is from the main leader, producing a thin, unbranched plant with one cyme. Apical dominance is released by cutting back the vine during production. Cutting back, or pinching, of a plant is labor intensive and compromises bloom for vegetative growth at time of sales. The purpose of this project was to eliminate manual pinching by treating young plants with chemical plant growth regulators (PGRs) that enhance branching without removal of the apical meristem. The first project evaluated the use of Atrimmec (dikegulac sodium), Fascination (BA+GA4+7), Florel (ethephon), and Dropp 50 (thidiazuron) on Clematis cultivars Ernest Markham, and Hagley Hybrid, and Clematis viticella 'Polish Spirit.' Plants treated with 800 mg·L-1 Atrimmec, or 800 or 1200 mg·L-1 Fascination experienced an increase in branch numbers. The second experiment manipulated the ratio of the components of Fascination, 6-BA and GA4+7, to reduce phytotoxicity experienced in the first experiment. The optimal ratio to enhance branching was 1:1, which is the stock solution for Fascination. All ratios produced phytotoxic symptoms. A third experiment tested lower rates of thidiazuron and added CPPU (forchlorfenuron) to the list of PGRs to test. The last experiment took the most effective PGR treatments, Atrimmec at 800 mg·L-1, and Fascination at 800 or 1200 mg·L-1, and compared them to the current production practices of pinching. Large flowering cultivars of clematis were used, including 'Comotesse de Bouchard,' 'Ernest Markham,' and 'Hagley Hybrid.' Atrimmec increased branch numbers and suppressed leader lengths without a mechanical pinch. Results from Fascination varied by cultivar.Master of Science
29
Zhang, Yun-Heng. "Biochemistry and molecular biology of binding proteins for plant growth regulators". Thesis, De Montfort University, 2000. http://hdl.handle.net/2086/13254.
Testo completoAbstract (sommario):
Plant growth regulators have a vital role in plant growth and development. The cellular response to these regulators depends on the presence and the action of specific receptors. The plant growth regulators and their receptors act together in complexes which determine the final effects of the plant growth regulators. In the research reported here, emphasis has been given to the regulation of the activity of the receptors themselves. The regulation of the N-l-naphthylphthalamic acid (N~A) receptor through phosphorylation and dephosphorylation and the regulation of the auxin binding protein (ABP) through gene manipulation have been investigated. NPA, an auxin transport inhibitor, was found to bind specifically to a crude membrane preparation from sugar beet seedling leaf cell suspension cultures. The in vitro binding was optimal at pH 4.5 and 4?C. Binding parameters for NP A binding were determined by Scatchard analysis. The dissociation constant (Kd) and binding protein concentration were found to be 1.71 x 10-7 mol dm-3 and 220 pmoles g-I membrane protein respectively. It was found that the amount of specific 3H-NPA binding was significantly increased by adding Mg2+ A TP to the binding assay solution; treatment of membrane preparations with acid phosphatase, prior to the NP A binding assay, resulted in lower specific binding. A TP activation and phosphatase inactivation were culture stage dependent. Although a considerable effect could be detected when using cells from day 8 (representing the linear phase), the same treatment did not alter the binding if cells from day I (representing lag phase) or day 14 (representing the stationary phase) were used. These observations have strongly highlighted the possible involvement of a phosphorylation and dephosphorylation mechanism in vivo in the regulation of the activity of the NP A receptor. High phosphatase activity was found in the supernatant, but not in the membrane pellet, after 50,000 g centrifugation. The presence of a membrane-bound auxin receptor, ABP, was demonstrated by Scatchard analysis in sugar beet seedlings. The Kd value and the receptor concentration were found to be 2.15 x 10-6 mol dm-3 and 68 pmoles g-I membrane protein. The protein could be solubilised either with the detergent Triton X-I 00 or by acetone-washing, with a recovery of about 40%. An acetone-solubilised ABP preparation could be partially purified by DEAE-Sephacel ion exchange chromatography, NAA-linked AH-Sepharose 4B affmity chromatography or Sephadex G-200 gel filtration. The recovery after any of these chromatographic treatments was very low so that successive chromatography for further purification was unsuccessful. The low level of detectable binding after purification resulted mainly from the low abundance of ABP in the plant material. Non-radioactive labelling and detection techniques were used to show that an ABP-probe hybridized to sugar beet genomic DNA during dot blotting. The present study has indicated that receptor activity could be regulated by a phosphorylation and dephosphorylation mechanism in plants. The investigation has also suggested that the effect of plant growth regulators on plant development could be regulated through the manipulation of the expression of their receptor genes.
30
Welsh, Claire Jillian. "Promoting resilience in rain grown cotton systems with plant growth regulators". Thesis, University of Sydney, 2020. https://hdl.handle.net/2123/23910.
Testo completoAbstract (sommario):
Rain grown cotton production is typified by significant climate variability with water limitation a focal constraint. Ensuing system exposure to climate risk results in substantial variability in production area, lint yield, lint quality and profit outcomes. Climate risk management involves manipulating multiple agronomic management and genetic solutions simultaneously; moderating existing limitations to reach the system water-limited yield potential. Such strategies can introduce management diversity to the farming system, but lack application agility, have added implementation costs and system rain-dependency often precludes their implementation. This thesis informs discourse regarding novel adaptive management opportunities utilising plant growth regulators (PGRs), to enable in-season responsive management of limitations under dynamic climatic conditions, offset climate variability and improve system resilience. Ensuing outcomes being increased farm-gate profits, through provision of improved crop resource use efficiencies, lint yield and quality outcomes, with less annualised variability. A scarcity of detailed information exists regarding cotton crop and plant responses to exogenous Gibberellin, Cytokinin and Gibberellin biosynthesis inhibiting PGR treatment scenarios, notably in early growth and under water-limited rain grown production contexts. Understanding these responses can enable future development of frameworks for strategic, predictive applications within rain grown cotton systems.
31
Wright, Glenn C. "Use of Plant Growth Regulators for Improving Lemon Fruit Size - 2005". College of Agriculture, University of Arizona (Tucson, AZ), 2005. http://hdl.handle.net/10150/198104.
Testo completoAbstract (sommario):
Lemons were treated with several plant growth regulators for the 2005-06 season, with the hope of improving fruit size. These PGR’s included CropSet, Accel, Maxim, Messenger and MT350. Although there were some increases in yield, these were just trends, and were not statistically significant. Similarly, there was no improvement in fruit size with application of the treatment
32
Bariola, Louis A. "Using Plant Growth Regulators to Control Pink Bollworms and Boll Weevils". College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219781.
Testo completo
33
Wright, Glenn C. "Use of Plant Growth Regulators for Improving Lemon Fruit Size - 2006". College of Agriculture, University of Arizona (Tucson, AZ), 2007. http://hdl.handle.net/10150/223662.
Testo completoAbstract (sommario):
Lemons were treated with several plant growth regulators for the 2006-07 season, with the hope of improving fruit size. These PGR’s included Bluestim, Accel, Maxim and MT1350. Although there were some increases in yield, these were just trends, and were not statistically significant. Similarly, there was no improvement in fruit size with application of the treatments.
34
Hood, L. R. "Multiple Plant Growth Regulator Use on Short Staple Cotton". College of Agriculture, University of Arizona (Tucson, AZ), 1993. http://hdl.handle.net/10150/209534.
Testo completoAbstract (sommario):
A field trial was initiated during the 1992 growing season to evaluate the activity of Cytokin and Piz applied alone or in combination to short staple cotton. The Cytokin treatment significantly increased lint yield over the other treatments. There were no statistically significant differences between the non-treated check and any other treatment. The Cytokin treatment increased lint yield an average of 81 pounds over the check plots. Fruit retention remained high throughout the season, indicating that Pix would not normally have been needed.
35
Hood, L. R. "Multiple Plant Growth Regulator Use on Short Staple Cotton". College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/210271.
Testo completoAbstract (sommario):
A field trial was conducted during the 1992 & 1993 growing seasons to evaluate the activity of Cytokin and Pic applied alone or in combination to short staple cotton. The Cytokin treatment significantly increased tint yield over the other treatments in 1992. There were no statistically significant seed cotton differences between the non - treated check and any treatment in 1993. Fruit retention remained high throughout 1992 and very high throughout the 1993 season. Under high fruiting conditions, use of a plant growth regulator would not normally be recommended.
36
Grossman, Mara Celeste. "Controlling Growth in Echinacea Hybrids". Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/77578.
Testo completoAbstract (sommario):
New hybrid Echinacea cultivars, based on crosses of Echinacea purpurea (L.) Moench with several other Echinacea species, have generated interest and excitement in the marketplace due to novel flower colors and forms. However, these cultivars vary significantly in their growth habits and requirements from the species. We examined factors in the production of Echinacea hybrid cultivars to provide guidance to growers. Foliar sprays 600 mg·L⁻¹ benzyladenine (BA) increased numbers of branches between 19% and 83% in Echinacea cultivars while 400 mg·L⁻¹ dikegulac sodium or 500 mg·L⁻¹ ethephon did not improve branching. Of several height control PGRs applied to E. ‘Marmalade,’ only plants treated with two applications of 5000 mg·L⁻¹ daminozide were shorter (24%) compared to untreated controls although flowering was also reduced by 70%. Echinacea ‘Harvest Moon’ plants were shorter in response to all of the PGRs applied, with the best results seen in plants treated with foliar sprays of uniconazole (one application of 30 mg·L⁻¹ or two applications of 15 mg·L⁻¹ ), two applications of 5000 mg·L⁻¹ daminozide, or 4 mg·L⁻¹ paclobutrazol applied once as a drench. Supplying N at 150 mg·L -1 during the growing season provided Echinacea cultivars adequate nutrition and maximized numbers of branches and flowers and shoot dry weight. In overwintering, fertilization treatments that resulted in low substrate electrical conductivity going into dormancy, 5.0 kg·m controlled release fertilizer 15N-3.9P-10K or 150 mg·L⁻¹ N using 15N-2.2P-12.5K applied using constant liquid feed, resulted in the highest survival rates of Echinacea cultivars. As a monitoring tool, SPAD measurements were not successful in predicting tissue N levels in Echinacea hybrids. Twenty-one hybrid cultivars acquired as stage 3 tissue culture plantlets were grown under one of three photoperiods (10-hour, 16-hour, or 24-hour) for 10 weeks before being transplanted to larger containers and grown under natural daylength until flowering. Providing Echinacea hybrid cultivars with a 16-hour photoperiod during liner production resulted in plants which flowered soonest without negative effects on growth. The need for height control PGRs varied by cultivar; however, overall height control PGRs controlled flower stalk height and increased market rating.Ph. D.
37
Snelson, Jonathan Bundy. "Plant Growth and Root Zone Management of Greenhouse Grown Succulents". Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/32398.
Testo completoAbstract (sommario):
Effects of media, soil moisture, fertility rate, and plant growth regulators on plant growth were investigated for 13 taxa of succulents.
Media: Liners were grown in five common greenhouse substrates: 80% peat, 60% bark + 30% peat moss, 80% pine bark/20% Permatil (v/v), 100% composted pine bark, or whole tree substrate until market ready. Overall, higher percentage bark mixes yielded smaller plants, with lower shoot dry weights, shoot heights and widths.
Soil Moisture: Liners were potted into a 60% bark/30% peat soilless potting mix. In group 1 , irrigation to container capacity occurred when volumetric soil moisture content fell below 30%, 20%, or 10%,. Group two (seven species) irrigation thresholds were shifted to 35%, 25%, and 15%. Effects of irrigation rate were significant in three of the 13 species studied, and those effects were species-specific.
Fertility Rate: Liners were potted into60% bark/30% peat substrate. Fertility reatments in group were 0, 50, 100, or 200 mg.L-1 nitrogen. Group 2 plants received treatments of 50, 150, 250, or 350 mg.L-1 nitrogen. Four of the 11 species studied were affected by nitrogen rate, with rates up to 200 mg.L-1 generally producing the largest plants.
PGRs: Seven species were potted into a 60% bark/30% peat substrate. Group one plants were treated with a foliar application of benzyladenine (Configure) at rates of 0, 400, 800, or 1600 mg.L-1. Group 2 plants were treated either BA at 0, 250, 500, or 1000 mg.L-1, dikegulac sodium (Augeo) at 400, 800, or 1600 mg.L-1, or a tank mix of 500 mg.L-1 Configure and 800 mg.L-1 Augeo. BA caused an increase in branches leaders or offsets in two species.Master of Science
38
Abdul-Razak, Mubarak Ali. "INFLUENCE OF GROWTH REGULATORS AND FERTILIZERS ON COTTON YIELD AND PLANT BEHAVIOR". Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/184196.
Testo completoAbstract (sommario):
The effect of the plant regulator Mepiquat chloride (PIXᵀᴹ) (1,1-dimethyl-piperidinium chloride), in the early flowering stage, and combinations with soil and foliar application of fertilizers was investigated through seven field experiments conducted in 1982 and 1983 at three University of Arizona experimental locations. Three upland cotton cultivars (Gossypium hirsutum L.), 'Deltapine 55', '61' and '62' were used. Cotton yield, boll properties, fiber properties, leaf chlorophyll content, plant height, plant partitioning and maturity were investigated. Petiole nitrate, leaf area index (LAI) and LAI interrelationship with yield were also included in this study. The use of PIX resulted in an increase in seed cotton yield and boll weight in one of the experiments, while fiber properties did not show any significant response to either PIX or fertilizers. PIX, however, had the tendency to enhance maturity by about 1 week. Use of PIX reduced plant height in all tested cultivars at all locations. The reduction in plant height ranged from 7 to 28% depending on the cultivar, location and the amount of PIX applied. The chlorophyll a and b content of leaves increased significantly as a result of PIX application in two of four tests, while their ratio decreased. Leaf area index between treatments were not significantly different except at one sampling date. In a regression study, however, yield was found to be related positively to LAI when soil and foliar application of fertilizer were added, while it was negative when PIX was applied. Neither PIX nor BALANCEᵀᴹ (1:18:18:1) application affected plant partitioning nor petiole nitrate concentration at most of the sampling dates.
39
Norton, E. R. "Scheduling Techniques for the Use of Pentia Plant Growth Regulator". College of Agriculture, University of Arizona (Tucson, AZ), 2005. http://hdl.handle.net/10150/198162.
Testo completoAbstract (sommario):
A single field study was conducted at the University of Arizona Safford Agricultural Center during the 2004 season to evaluate the utilization of a feedback technique that is based upon plant growth and development to schedule applications of the new plant growth regulator (PGR) from BASF, Pentia. A simple three treatment study was constructed consisting of a control treatment (no Pentia application), a scheduled treatment (application of 16 oz/acre at first bloom regardless of plant growth), and a feedback treatment (applications based upon plant growth and development). Application decisions on the feedback treatment were made using height to node ratios (HNR) as a measure of plant vigor. Treatment applications were made on the scheduled regime on 14 July with a one time 16 oz/acre application. The feedback regime received an application (16 oz/acre) of Pentia five days later on 19 July. An additional application (16 oz/acre) was made on the feedback treatment on 3 August due to continued high HNR levels. Significant differences in plant vigor were observed post application among the three treatments as measured by end of season HNR ratios. Yield results indicated positive lint yield response to Pentia application with both the scheduled and feedback treatment producing statistically higher yields than the control. Differences between the feedback and scheduled treatments were not statistically different however a slight yield increase was observed in the scheduled treatment. The second Pentia application made to the feedback treatment was not necessary. End of season HNR measurements indicate that the additional 16 oz/acre application suppressed growth to below the average baseline for HNR. These results indicate that potential positive response to PGR applications, specifically Pentia, under conditions of high vigor.
40
Eksteen, Lambertus Lochner. "Reducing height and lodging in canola (Brassica napus L.) using plant growth regulators". Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95845.
Testo completoAbstract (sommario):
Thesis (MScAgric)--Stellenbosch University, 2014.ENGLISH ABSTRACT: In South Africa, canola (Brassica napus L.) is produced under short day conditions during winter months. These conditions, together with high fertiliser application levels required to maximize grain yields, often result in tall growing bulky crops which are prone to lodging. This will especially be true if canola production is expanded to irrigated areas. Plant growth regulators (PGRs) have successfully been used to reduce canola plant height and lodging under experimental conditions in Australia and are worldwide commercially used to reduce plant height and lodging in winter cereals such as wheat and barley. The primary objective of this study was to determine the effect of anti-lodging PGRs on the agronomic and quality characteristics of commercial canola cultivars under South African conditions. This study was conducted under field conditions at three research farms, as well as controlled glasshouse conditions at Welgevallen Research Farm, situated in the Western Cape Province of South Africa. Foliar treatments consisted of a control (untreated) and four PGRs; CeCeCe® 750 (chlormequat chloride), Moddus® 250 EC (trinexapac-ethyl), Primo MAXX® (trinexapac-ethyl), and Kelpak®, applied either individually or in combination with wetting agent at budding stage (growth stage 3.1) of canola. Whilst glasshouse trials were conducted with spring canola cultivars “Hyola 555TT” and “43C80”, field trials were done with Hyola 555TT only. Monitoring and measuring various plant parameters during different growth stages of canola, the morphological and physiological impact of PGR-treatments on growth and development were determined. Though Primo MAXX® tends to reduce plant height in all trials; reductions were only significant during one of the glasshouse trials. Fortunately, compared to the control, none of the PGRs significantly reduced the leaf area, number of flowers or number of pods plant-1 during this study, while Primo MAXX® and Moddus® 250 EC tend to increase the grain yield under field conditions. This study indicates that PGRs can possibly be used to improve lodging resistance and yield of canola. Identifying the most effective PGRs on specific cultivars, the results of the study will contribute to the knowledge of using PGRs in canola to reduce lodging and improve grain yields in South Africa.
AFRIKAANSE OPSOMMING: In Suid-Afrika word canola (Brassica napus L) gedurende die wintermaande onder kort-dagtoestande verbou. Hierdie verbouingstoestande, tesame met verhoogde toediening van bemesting vir maksimum opbrengs, lei dikwels tot welige, hooggroeiende plantegroei, wat „n geneigdheid toon om om te val (lodge). Hierdie probleem vererger indien canola onder besproeiingstoestande gekweek sou word. Plantgroeireguleerders (PGRs) is reeds met sukses onder eksperimentele toestande in Australië gebruik om die planthoogte en dus omval (lodging) van canola te beperk. Plantgroeireguleerders word reeds kommersieel gebruik om planthoogte en omval van wintergraangewasse, soos koring en gars te verminder. Die hoofdoel van hierdie studie was om die effek van omval-teenwerkende PGRs op die agronomiese en kwaliteitseienskappe van kommersiële canola-kultivars onder Suid-Afrikaanse groeitoestande te bepaal. Hierdie studie is uitgevoer d.m.v. veldproewe op drie navorsingsplase, sowel as gekontrolleerde glashuisproewe te Welgevallen Navorsingsplaas, geleë in die Wes-Kaapprovinsie van Suid-Afrika. Blaartoedienings het bestaan uit „n kontrole (onbehandeld) en vier PGRs: CeCeCe® 750 (chlormequat chloride), Moddus® 250 EC (trinexapac-ethyl), Primo MAXX® (trinexapac-ethyl) en Kelpak®, wat afsonderlik of in kombinasie met benattingsmiddels toegedien is tydens die blomknopverskyningstadium (groeistadium 3.1) van canola. Die glashuisproewe is uitgevoer met lente-canolakultivars, nl. “Hyola 555TT” en “43C80”, terwyl veldproewe slegs uitgevoer is met Hyola 555TT. Verskeie plantparameters is gemonitor en gemeet gedurende die verskillende groeistadia van canola, waartydens en die morfologiese en fisiologiese impak van PGR-toedienings op die groei- en ontwikkeling van canola bepaal is. Alhoewel Primo MAXX® neig om die planthoogte in al die proewe te verkort, het dit planthoogte slegs beduidend verkort in een van die glashuisproewe. Geen van die PGRs het in vergelyking met die kontrole, die blaar-oppervlakte, aantal blomme of aantal peule plant-1 beduidend verminder gedurende die studie. Primo MAXX® en Moddus® 250 EC het inteendeel daartoe geneig om die saadopbrengs onder veldtoestande te verhoog. Hierdie studie toon dus dat PGRs moontlik gebruik kan word om omval te verminder en die opbrengs van canola te verhoog. Deur die mees doeltreffendste PGRs op spesifieke kultivars te identifiseer, kan die resultate van hierdie studie bydra tot die kennis van die gebruik van PGRs op canola, om omval te voorkom en saadopbrengs in Suid-Afrika te verhoog.
41
Zhou, Dongfang. "Using Plant Growth Regulators to Improve the Quality of Containerized Herbaceous Peony". Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/98808.
Testo completoAbstract (sommario):
Herbaceous peonies (Paeonia lactiflora Pall.) are common perennials used both in gardens and the landscape as well as for cut flowers. Peonies require a chilling period to break dormancy but not for flower bud differentiation. For all studies discussed in this dissertation, two peony cultivars, Sarah Bernhardt and Inspecteur Lavergne, small (3–5 eye) crowns from Holland were potted in 3.8-L pots in mid-November of 2017 and 2018. Our overall objective was to determine if we could manipulate chilling time, along with application of gibberellic acid (GA3) and growth retardants, to produce marketable containerized peonies from a small crown in a single season (November to May).
We evaluated chilling, GA3 and a growth retardant (uniconazole; UNZ) under controlled chilling and greenhouse forcing conditions. All potted plants were held outdoors at Battlefield Farms (Rapidan, VA, 38˚ N) for 4 weeks [in 2017, 400 chilling units (CU) according to Fulton Chilling Model] or in a 10°C cooler for 5.5 weeks (in 2018, 400 CU) to root, then placed in a 5°C cooler for 3, 4 or 5 weeks (total 752, 869 or 986 CU). GA3 was applied as a 0 or 100 mg·L-1 drench at 250 ml/pot after the plants were moved into the Virginia Tech greenhouse (Blacksburg, VA, 37˚ N) for forcing. Uniconazole drenches were applied to each cultivar under each chilling treatment at 355 ml/pot at 0, 15, or 20 mg·L-1 at 7 days after the GA3 drench applications. Three weeks chilling at 5°C (752 CU total) provided sufficient chilling for 'Sarah Bernhardt' and 'Inspecteur Lavergne'. Application of GA3 reduced production time and resulted in a greater number of shoots, and, in three of the four studies, increased the number of flowering shoots in three of the four studies. Substrate drench application of 15 mg·L-1 UNZ prior to spring emergence reduced plant width moderately resulting in improved compactness of both cultivars.
We evaluated the effects of plant growth retardants applied with different methods at different stages of production on the growth and development of containerized peony under nursery conditions. All potted plants were placed in an unheated coldframe at the Virginia Tech Urban Horticulture Center (Blacksburg, VA, 37˚ N) for one month after potting to promote rooting and then were moved outdoors to a gravel pad to receive natural chilling from November to February. In 2017–18, substrate drenches of UNZ at 0, 15, 30 or 45 mg·L-1 or paclobutrazol (PBZ) at 0, 30, 60 or 90 mg·L-1 at 237 mL/pot were applied about 4 weeks after potting for both cultivars in mid-December 2017. In 2018–19, fall drenches of uniconazole at 0, 15, 30 or 45 mg·L-1 at 237 mL/pot were applied about 4 weeks after potting in mid-December 2018, or spring sprenches of uniconazole were applied at 0, 15, 30 or 45 mg·L-1 at 840 mL·m-2 in March 2019 after 50% shoot emergence for each cultivar. Plant growth retardant applications had little effect on plant growth of either cultivar, but treated plants were of a darker green color compared to the control plants. In addition, higher rates of uniconazole applied as a fall drench increased the number of flowering shoots of both cultivars and the percentage of plants flowering for 'Sarah Bernhardt' in the second season of the study where plants were more protected from spring freezes. Fall paclobutrazol drenches or spring uniconazole sprenches had little effect on flowering.
To determine the best timing for spring GA3 applications under nursery conditions, we applied three models based on natural chilling accumulation. The models were a modified Fulton Chilling Model (FCM) for herbaceous peonies, Blackberry Chilling Model 5 (BCM5) for blackberry, or a visual development model (VDM) which was 10% of plants showing shoot emergence in the spring. We choose 1,000 CU for the first two chilling models as the chilling required to break dormancy and promote normal plant growth and flowering. All plants were held in an unheated coldframe at the Virginia Tech Urban Horticulture Center for one month after potting to promote rooting, then were moved outdoors to a gravel pad to receive natural chilling over the winter months. Drenches of 0 or 100 mg·L-1 GA3 were applied at 250 mL/pot to each cultivar under each chilling model when the specific conditions were met. Due to greater winter injury in the 2017–18 season, results varied by year. In the 2017–18 season, GA3 applied according to BCM5 reduce days to emergence for both cultivars and reduce the plant width of 'Inspecteur Lavergne', and later application according to BCM5 and VDM reduced plant length and diameter of 'Sarah Bernhardt'. Reductions in plant size may have been due to greater winter injury due to the earlier emergence of GA3 treated plants. In the 2018–19 season, earlier GA3 drench applications tended to reduce days to emergence for both cultivars and the FCM application reduced days to bud for 'Inspecteur Lavergne', but GA3 drench applications had no effect on plant size. GA3 can be applied after chilling (1,000 CU) using a suitable chilling model such as FCM for peonies, or BCM5, or VDM, but GA3 had little effect on plant development under nursery conditions.
We also evaluated GA3 effects on peony bud differentiation and development during controlled chilling and early forcing, as well as effects on growth and flowering. All potted plants were held in a 10°C cooler for 5.5 weeks (400 CU) to root, then placed in a 5°C cooler for 4 weeks (total 869 CU). GA3 was applied at 0 or 100 mg·L-1 pre-chilling or post-chilling as a 250 ml/pot drench. Bud differentiation and development of excised buds were evaluated using a stereomicroscope at potting, after rooting (before chilling), after 1, 2, 3 or 4 weeks of chilling, and at 5, 10 or 15 days after the beginning of forcing. All buds were removed from the sample plants, measured for bud length and diameter, and dissected under a stereomicroscope to assess differentiation stages. Root dry weights and crown dry weights were also determined after rooting, after chilling, and at 15 days of forcing. Ten plants of each treatment were grown in the Virginia Tech greenhouse after chilling until flowering. GA3 applications did not advance the bud development stage because most of buds were already in the reproductive stages before dormancy, but GA3 enhanced bud elongation during chilling and the early forcing period. Our findings suggest that GA3 applications can reduce the time to emergence and flowering, as well as increase the numbers of shoots and flowering shoots. GA3 applied right after rooting in, prior to the chilling period, or before greenhouse forcing, resulted in earlier emergence and flowering with higher quality plants. However, earlier applications, pre-chilling, tended to produce plants with more shoots.
Overall, our experiments indicate that three weeks of chilling at 5°C (752 CU total) is a sufficient chilling regime for forcing 'Sarah Bernhardt' and 'Inspecteur Lavergne' peonies, and 1,000 CU of naturally accumulated chilling is sufficient for nursery production. GA3 applications can reduce the time to emergence and flowering, as well as increase the numbers of total shoots and flowering shoots. Timing of GA3 application is flexible; it can be applied right after rooting, before the chilling period, just before greenhouse forcing, or after shoots have begun to emerge. Plant growth retardant applications had a little effect on the growth of tested cultivars, but all plants treated with growth retardants are generally darker green in color. Additionally, growth retardant applications have some positive effects on flowering.Doctor of Philosophy
Herbaceous peonies (Paeonia lactiflora Pall.) are common perennials used both in gardens and the landscape as well as for cut flowers. Peonies require a chilling period to break dormancy but not for flower bud differentiation. For all studies, two peony cultivars, Sarah Bernhardt and Inspecteur Lavergne, 3 to 5 eye small crowns from Holland were potted in 3.8-L pots in mid November of 2017 and 2018. Our overall objective was to determine if we could manipulate chilling time, along with application of gibberellic acid (GA3) and growth retardants, to produce marketable containerized peonies from a small crown in a single season (November to May). We evaluated chilling, GA3 and a growth retardant (uniconazole) under controlled chilling and greenhouse forcing conditions. We evaluated the effects of plant growth retardants (uniconazole or paclobutrazol) applied with different methods (fall drenches or spring sprenches) at different stages of production on the growth and development of containerized peony under nursery conditions. To determine the best timing for spring GA3 applications under nursery conditions, we applied three models based on natural chilling accumulation. We also evaluated GA3 effects on peony bud differentiation and development during controlled chilling and early forcing, as well as growth and flowering. Overall, 3 weeks chilling at 5°C [752 chilling units (CU) total] is a sufficient chilling regime for forcing 'Sarah Bernhardt' and 'Inspecteur Lavergne' peonies, and 1000 CU naturally accumulated chilling is sufficient for nursery production. GA3 applications can reduce the time to emergence and flowering, as well as increase the numbers of shoots and flowering shoots. Timing of GA3 application is flexible, it can be applied right after rooting, after the chilling period, or after shoots have begun to emerge. Plant growth retardant applications had little effect on plant growth of either cultivar, but all plants treated with growth retardants were darker green in color. Additionally, growth retardant applications had some positive effects on flowering.
42
McCarthy, Timothy James. "Studies towards the total synthesis of (+)-ovalifoliene and other plant growth regulators". Thesis, University of Liverpool, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314551.
Testo completo
43
Grossman, Mara Celeste. "Use of Plant Growth Regulators to Improve Branching of Herbaceous Perennial Liners". Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/32830.
Testo completoAbstract (sommario):
The objective of this study is to evaluate the efficacy of PGRs to improve branching during
production of herbaceous perennial liners and finished plants. The effects of benzyladenine (BA)
on the branching and root and shoot growth of Agastache Clayt. Ex Gronov. 'Purple Hazeâ ,
Gaura lindheimeri Engelm. & A. Gray 'Siskiyou Pink', Lavandula à intermedia Emeric ex
Loisel. 'Provence', Leucanthemum à superbum (Bergmans ex J.W. Ingram) Bergmans ex Kent.
'Snowcap', and Salvia à sylvestris L. (pro sp.) 'May Night' was tested. Root dry weight was found
to be highly correlated to root volume and root surface area. In liners, all taxa except Salvia had
increased branching while all except Gaura had reduced rooting. Increased branching was not
evident in most taxa as finished plants. The effects of BA on Aster 'Professor Anton Kippenbergâ
(Symphyotrichum novi-belgii L.'Professor Anton Kippenburg'), Campanula punctata Lam.
'Cherry Bells,' Cosmos atrosanguineus (Hook) Voss., Verbena bonariensis L. 'Lollipop,'
Rosmarinus officinalis L.'Hill Hardy' and Veronica spicata L. â Goodness Grows.â was tested. BA
increased branching of three taxa as liners while roots were not affected. The addition of IBA did
not improve root growth in BA-treated plants. Dikegulac sodium and ethephon were evaluated as
branching enhancers in the same six perennials. Dikegulac increased branching of all except
Campanula while ethephon increased branching in Veronica and Verbena. The effects of
application time of BA on the branching of Agastache Clayton ex Gronov. â Tutti Fruttiâ and
Verbena bonariensis 'Lollipop' was evaluated with application of BA at 0, 7, 14, 17, 20 and 21
days after sticking (DAS); however growth was reduced in plants treated before rooting had
occurred. Agastache finished plants treated at 14 DAS had increased branching whereas
iii
branching was not affected in Verbena liners or finished plants. The effects of single or multiple
applications of BA and dikegulac sodium on Sedum spectabile Boreau â Autumn Joy,' Gaillardia
aristata Pursh â Gallo Red,â Phlox paniculata L. â Bright Eyes,â Nepeta racemosa Lam. â Walkerâ s
Low,â Delosperma NE Br. â Table Mountain,â and Achillea L. â Moonshineâ were evaluated. Two
applications of PGR was most effective at increasing branching in finished plants. High rates of
dikegulac sodium reduced growth in most plants studied while BA increased branches without
negatively affecting plant growth.Master of Science
44
Ibrahim, Mohammed. "Physiological and metabolic responses of two rose varieties to plant growth regulators". Thesis, Ibrahim, Mohammed (2018) Physiological and metabolic responses of two rose varieties to plant growth regulators. PhD thesis, Murdoch University, 2018. https://researchrepository.murdoch.edu.au/id/eprint/45991/.
Testo completoAbstract (sommario):
Rose (Rosa hybrida) is one of the most popular cut flowers with a worldwide production of more than 300 million stems per year. The perfume industry, which relies on a range of scented rose varieties, is also an important industrial application for roses. Among the numerous types of roses are some recent varieties including Hybrid Tea and Floribunda roses. The major problem in Australia is accelerated pre- and post-harvest flower drop and senescence, caused by deficiencies in endogenous plant growth regulators (PGRs). PGRs play important roles in the growth and development of flowers, especially in aromatic plants, stimulating the emission of volatile organic compounds (VOCs). The PGRs benzyladenine (BA) and naphthalene acetic acid (NAA) which belong to cytokinin and auxin group of PGRs respectively, are used by the floriculture industry as important growth regulators for promoting rose growth and development. However, it is still unknown that how these regulators and their application dosages influence rose plants. Therefore, this thesis aimed to evaluate and determine the efficacy of various concentrations of BA and NAA on arrange of morphological and physiological characteristics of roses to increase flowers longevity in two rose varieties (Floribunda and Hybrid Tea). In addition, this study was conducted to understand how different concentrations of BA and NAA effect the metabolic changes in different rose tissues together with a comparison of VOCs changes.
This work in this thesis developed and optimized the headspace solid-phase microextraction (HS-SPME) with three-phase fibre 50/30μm divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) coupled with gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS) method for exploring and analysing VOCs emitted from the intact and excised flowers, leaves, and stems as well as from the rhizosphere and whole plants of the two rose varieties.
This study has optimized different environmental factors involved in the performance of the two rose varieties was conducted, and three physiological characteristics photosynthesis rate, respiration rate, and chlorophyll content were assessed. Three different concentrations (0, 100 and 200 mg/L) of BA and NAA were applied to the two rose varieties, and different morphological and physiological characteristics were evaluated. For physiological effects (photosynthesis rate and chlorophyll index) studies, application of 200 mg/L of both BA and NAA were shown to increase plant height, numbers of branches and flowers, stem and flower diameters, length of flower stems and flower longevity, compared to the control. However, for the respiration rate, the control plants had significantly superior performance to the plants treated with 100 and 200 mg/L BA and NAA, for both rose varieties.
The VOC profiles of the two rose varieties were characterized by the optimized HS-SPME-GC method. The effects of different concentrations (0, 100 and 200 mg/L) of BA and NAA on the VOCs emitted from different rose tissues for the two rose varieties were determined. The highest amounts extracted, and evaluated from the sum of peak areas were achieved after the application of 200 mg/L BA and NAA in both varieties. Of the emitted VOCs, 20 were significantly different in treated compare to non-treated Floribunda and Hybrid Tea roses from different rose tissues. Moreover, five compounds 4-heptyn-2-ol, cis-muurola-4(14)5-diene, γ -candinene, y-muurolene and prenyl acetate increased significantly after applications of 200 mg/L of BA and NAA. These five compounds have great potential to develop commercially important new rose growth regulators. The actual dosages of BA applied to the leaves was determined using filter paper as 11.16 mg/cm2 and 7.17 mg/cm2 for Hybrid Tea and Floribunda respectively. In conclusion, the application to rose plants of different concentrations of BA and NAA can promote a number of changes to both morphological and physiological parameters, and in turn have a significant effect on metabolite changes in different rose tissues. Application BA and NAA method could be applied to other floriculture plants to increase the flowers production in rose or other ornamental plants.
45
Rethwisch, Michael D., Michael D. Kruse e Justin Parker. "Effects of Aerially Applied Plant Growth Regulators on Alfalfa Quality and Yields". College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/202434.
Testo completoAbstract (sommario):
Plant growth regulators were aerially applied on April 26, 1996, to two alfalfa fields, one (Cibola) in its first year of production and the other field (CUF 101) in its third year. The first year field was approximately 50% through the cutting cycle and the third year field was approximately 30% through the cutting cycle when applications were made. No statistical differences were noted in hay tonnage the first cutting after application. Yield increases due to treatments were noted in the second cutting and maximum increases ranged from 277 -461 lbs of hay per acre. No yield or quality differences were noted the third cutting after application. The two fields differed in their response. The lowest rates of plant growth regulators produced higher yields in the first year field, but these treatment rates had greatly lowered hay quality the previous cutting. These effects were not noticed in the third year stand field. Increased hay tonnage was noted in the third year field from the 16 oz/acre rates, but was not evident in the first year field. Hay quality was usually highest in the check the first two cuttings after treatment. It is unknown if the differences noted between the two fields are due to different age of plants, variety and/or stage of growth when treatments were applied.
46
Rethwisch, Michael D., Greg Hurtado e Rosario Hurtado. "Comparison of Various Plant Growth Regulators on Pima S-7 Cotton Yields". College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/210772.
Testo completoAbstract (sommario):
All plant growth regulators and nutritional products applied to Pima S-7 cotton during bloom economically increased lint yields, with increases ranging from 80 - 261 lbs. /acre. Greatest increase was noted with Boll-Set Plus, a product that contains raised levels of calcium and zinc. Cytokin and Boll -Set Plus significantly increased yields at one location. A lint yield increase of approximately 40 lbs/acre was noted when Tech-Flo Alpha was added to Cytokin. A single application of Foliar Triggrr resulted in equal yields as two applications of the Cytokin plus Tech-Flo Alpha.
47
Clark, L. J., e E. W. Carpenter. "Plant Growth Regulator Studies at the Safford Agricultural Center, 1993". College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/209604.
Testo completo
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Clark, L. J., e E. W. Carpenter. "Plant Growth Regulator Studies at the Safford Agricultural Center, 1994". College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/210270.
Testo completoAbstract (sommario):
Methanol, Cytokin and PGR IV plant growth regulators were tested on long and short staple cotton on the Safford Agricultural Center in 1994. It was a follow up study on Methanol and Cytokin and a first time look at PGR IV.
49
Norton, E. R., e H. J. Borrego. "Evaluation of Plant Growth Regulator Formulations in Arizona Cotton Production Systems". College of Agriculture, University of Arizona (Tucson, AZ), 2006. http://hdl.handle.net/10150/198211.
Testo completoAbstract (sommario):
A single experiment was conducted in 2005 at the University of Arizona Safford Agricultural Center in an effort to continue to evaluate several different formulations of the plant growth regulator (PGR) mepiquat chloride. Plots were established with the cultivar Deltapine DP 655BR on 19 April 2005. Four treatments were imposed on 18 July 2005 of 16 oz./acre applications of Mepex, Pix Ultra, and Pentia, plus a control plot. Plots were four 36” rows wide and extended the length of the irrigation run of 220 feet. Plots were arranged in a randomized complete block design with four replications. Plots were monitored with respect to plant growth and development through collecting plant measurement data over the course of the season. Yield results were obtained by harvesting the center two rows of each plot and weighing the resultant seedcotton. Fiber quality was determined from a sub-sample collected from each plot at harvest. Plant growth and development trends indicated strong fruit retention levels all season with strong early season vigor. Each of the PGR applications had significant impact on plant height effectively reducing internode elongation. Lint yield results indicated increased yields for all PGR applications over the control with Pentia producing a statistically significant higher yield. Fiber quality was also impacted by PGR application. All PGR treatments had trends toward higher staple length, fiber strength, and fiber uniformity. These results are consistent with previous results indicating that PGR applications have the potential to increase yields under situations were high vigor is present.
50
Leitao, Daniela. "Effects of commercial kelp extract and plant growth regulators on growth of Gracilaria gracilis in culture". Master's thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/6707.
Testo completoAbstract (sommario):
The addition of a local commercial seaweed extract (Kelpak®) to crop plants has proven to be beneficial as it improves growth and yields. Its efficiency has been attributed to its production method that involves a cold process, resulting in a product containing significant amounts of plant growth regulators (auxins and cytokinins). The aim of this study was therefore to investigate the effects of this commercial seaweed concentrate (Kelpak®) on the growth of Gracilaria gracilis (Stackhouse) Steentoft, Irvine et Farnham, with a view to the potential in mariculture, especially as this red seaweed is currently under cultivation in South Africa as feed in abalone aquaculture.