Four isosteric series of plant growth-regulating compounds were prepared. Using an Avena sativa coleptile assay system, derivatives in series I and IV inhibited segment elongation to a greater degree than did comparable derivatives in series II and III.

Made available in DSpace on 2014-06-11T19:22:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-01-29Bitstream added on 2014-06-13T18:48:48Z : No. of bitstreams: 1 souza_fs_me_botfca.pdf: 722599 bytes, checksum: bddbe2539a4c9c196d08d8670e432f38 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente trabalho teve por objetivo avaliar o comportamento de plantas de algodão submetidas à aplicação de doses de cloreto de mepiquat e precipitações pluviais ocorrendo em diferentes momentos após a aplicação do produto. Procurou-se ainda desenvolver um método simples de estimativa da dose do produto a ser aplicada. Os tratamentos foram constituídos de três doses do regulador a base de cloreto de mepiquat (PIX®): 7,5, 15,0 e 22,5 g ha-1 e seis intervalos de tempo para aplicação de chuva simulada de 20 mm de intensidade: 0, 1, 3, 6, 12 e 24 horas, mais um tratamento sem a aplicação de chuva. Foram utilizados vasos de 12 litros de capacidade e seis sementes pré-germinadas com posterior desbaste para duas plantas por vaso. O delineamento experimental utilizado foi o inteiramente casualizado com quatro repetições. Os parâmetros avaliados foram: altura de plantas, número de ramos reprodutivos, massa de matéria seca, retenção de estruturas reprodutivas (coleta de estruturas reprodutivas e estruturas perdidas) e área foliar. Os resultados mostraram que o efeito do regulador foi prejudicado pela ocorrência de chuva nos momentos mais próximos a sua pulverização. As maiores doses mostraram ter efeito mais significativo nos parâmetros de crescimento avaliados, mostrando que chuvas ocorridas em momentos mais próximos após a pulverização causam maior comprometimento da ação do regulador nas plantas de algodão. É possível calcular a dose de regulador a ser aplicada conhecendo-se a altura atual das plantas. / The research had the objective to evaluate the behavior of cotton plants submitted to the application of doses of Mepiquat Chloride and precipitations happening in different times after the application of the product. A tentative for developing a simple method for estimating the dose of the product that would be applied was tried. The treatments were constituted of three doses of the growth regulator, mepiquat chloride (PIX®): 7,5, 15,0 and 22,5 g ha-1 and six time intervals for the application of simulated rain of 20mm of intensity: 0, 1, 3, 6, 12 and 24 hours, and one treatment without rain. Plots of 12 liters of capacity and six pre-germinated seeds were used with subsequent rough-hewing for two plants per plot. The experimental design used was the completely randomized with four replications. The parameters analyzed were: height of plants, number of reproductive branches, weight of dry matter, collecting of reproductive structures and lost structures, and leaf area. The results showed that the effect of the growth regulator was harmed by the rain occurrence in the closest moments of the application of the growth regulator. It was possible to calculate the regulator dose to be applied knowing the actual height of the plants.

Orientador: Ciro Antonio Rosolem / Banca: João Domingos Rodrigues / Banca: Ederaldo José Chiavegato / Resumo: O presente trabalho teve por objetivo avaliar o comportamento de plantas de algodão submetidas à aplicação de doses de cloreto de mepiquat e precipitações pluviais ocorrendo em diferentes momentos após a aplicação do produto. Procurou-se ainda desenvolver um método simples de estimativa da dose do produto a ser aplicada. Os tratamentos foram constituídos de três doses do regulador a base de cloreto de mepiquat (PIX®): 7,5, 15,0 e 22,5 g ha-1 e seis intervalos de tempo para aplicação de chuva simulada de 20 mm de intensidade: 0, 1, 3, 6, 12 e 24 horas, mais um tratamento sem a aplicação de chuva. Foram utilizados vasos de 12 litros de capacidade e seis sementes pré-germinadas com posterior desbaste para duas plantas por vaso. O delineamento experimental utilizado foi o inteiramente casualizado com quatro repetições. Os parâmetros avaliados foram: altura de plantas, número de ramos reprodutivos, massa de matéria seca, retenção de estruturas reprodutivas (coleta de estruturas reprodutivas e estruturas perdidas) e área foliar. Os resultados mostraram que o efeito do regulador foi prejudicado pela ocorrência de chuva nos momentos mais próximos a sua pulverização. As maiores doses mostraram ter efeito mais significativo nos parâmetros de crescimento avaliados, mostrando que chuvas ocorridas em momentos mais próximos após a pulverização causam maior comprometimento da ação do regulador nas plantas de algodão. É possível calcular a dose de regulador a ser aplicada conhecendo-se a altura atual das plantas. / Abstract: The research had the objective to evaluate the behavior of cotton plants submitted to the application of doses of Mepiquat Chloride and precipitations happening in different times after the application of the product. A tentative for developing a simple method for estimating the dose of the product that would be applied was tried. The treatments were constituted of three doses of the growth regulator, mepiquat chloride (PIX®): 7,5, 15,0 and 22,5 g ha-1 and six time intervals for the application of simulated rain of 20mm of intensity: 0, 1, 3, 6, 12 and 24 hours, and one treatment without rain. Plots of 12 liters of capacity and six pre-germinated seeds were used with subsequent rough-hewing for two plants per plot. The experimental design used was the completely randomized with four replications. The parameters analyzed were: height of plants, number of reproductive branches, weight of dry matter, collecting of reproductive structures and lost structures, and leaf area. The results showed that the effect of the growth regulator was harmed by the rain occurrence in the closest moments of the application of the growth regulator. It was possible to calculate the regulator dose to be applied knowing the actual height of the plants. / Mestre

The apple rootstock ‘Geneva® 41’ (‘G.41’), is desirable for its resistance to fire blight, Erwinia amylovora, while producing high yields. However, ‘G.41’ and other Geneva® selections tend to form weak graft unions in the nursery that are susceptible to breaking in the wind, at harvest, or during shipment. In order to understand and remedy this graft union weakness, six scions (‘Fuji’, ‘Gala’, ‘Honeycrisp’, ‘McIntosh’, ‘Pink Lady’, and ‘Scilate’) by seven rootstocks (‘G.41’, ‘G.935’, ‘G.214’, ‘G.11’, ‘M.9-NIC 29’, ‘B.9’ and ‘EMLA 26’), by two grafting methods (chip bud and saddle graft) in a factorial design were tested for graft union flexural strength and flexibility. Additionally, plant growth regulators (PGR) were applied to trees with ‘G.41’ as rootstock as a solution to overcome graft union weakness. Transpiration rate and hydraulic resistance were measured for comparison of a weak graft forming rootstock (‘G.41’) to a strong graft forming rootstock (‘M.9-NIC 29’). ‘G.41’ consistently formed a weaker graft union regardless of scion or grafting method. Scions such as ‘McIntosh’ and ‘Pink Lady’ formed stronger graft unions, while ‘Scilate’ and ‘Honeycrisp’ form weaker graft unions. Saddle grafting did not improve graft union strength. Nurseries that graft on ‘G.41’ should choose scions that form stronger graft unions. Benzyl adenine (BA) in a latex paint increased the strength and flexibility of the graft union relative to scion cross sectional area (SCSA), but further research is needs to identify more efficient methods of application. Rootstock effect on transpiration rate was different between years. No detectable differences were found for hydraulic resistance through the graft union of different rootstocks, suggesting weaker graft unions did not limit hydraulic conductance or transpiration rate. Thus graft union weakness is not an indicator of poor vascular connection.

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on September 22, 2009). Thesis advisor: Dr. Bruce Barrett. Includes bibliographical references.

Thesis (MScAgric)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Maintaining constant high yields in „Abate Fetel‟ and „Forelle‟ orchards in South Africa is challenging. Improving productivity in these orchards could be achieved by increasing fruit set and fruit size. Fruit size is an important marketing and quality parameter and has a significant effect on the economic value of fruit. Various protocols to improve fruit set are used by South African producers but these are not well researched. We therefore evaluated different combinations of plant growth regulators including gibberellic acid (GA3), gibberellins 4+7 (GA4+7), GA4+7 combined with 6-benzyladenine (6-BA), aminoethoxyvinylglycine (AVG) and prohexadione-calcium (P-Ca) in combination with trunk girdling during flowering on „Forelle‟ and „Abate Fetel‟ to determine the best fruit set strategy. All applied growth regulators improved fruit set relative to an untreated control over two consecutive seasons, but GA3 and P-Ca reduced return bloom and AVG resulted in smaller fruit size relative to the other treatments. The application of synthetic cytokinins are believed to enhance fruit size by stimulating and extending the cell division period in fruit when applied at the correct stage of fruit growth. In addition, combination of P-Ca with GA4+7 was used successfully on Japanese pear (Pyrus pyrifolia Nakai) and „Bing‟ sweet cherry to improve fruit size. This combination of GA4+7 and P-Ca was evaluated and combined with 6-BA treatments on European pear (Pyrus communis L.) cultivars, Forelle and Abate Fetel, to see if a similar effect on fruit size could be achieved under South African growing conditions. On both „Forelle‟ and „Abate Fetel‟ the combination of GA4+7 and P-Ca increased fruit size, but was more pronounced in „Abate Fetel‟. Growth regulators N-phenyl-N‟ -1,2,3-thiadiazol-5-ylurea (TDZ), N (2-chloro-4-pyridyl)-N‟ -phenylurea (CPPU), 6-BA and 2,4-dichlorophenoxyacetic acid (2,4-D) successfully increased fruit size in pear cultivars Coscia and Spadona in Israel. These growth regulators were applied to „Forelle‟ and „Abate Fetel‟ to determine if a similar effect could be achieved. None of the synthetic cytokinins applied had a significant effect on increasing fruit size in these two cultivars over two consecutive seasons although 6-BA increased return bloom and 2,4-D application resulted in increased fruit set. The stage when the cell division period in „Forelle‟ and „Abate Fetel‟ ends was also determined as 34 and 45 days after full bloom respectively, which can be used in the future to better plan the timing of fruit size enhancement treatments. Based on results from various fruit set and fruit size improvement trials, it can be recommended to use GA4+7 or AVG to increase fruit set on „Forelle‟ and „Abate Fetel‟, depending on the fruit set history of the orchard. Results from fruit size improvement trials were variable, and emphasises the fact that a balance between yield and fruit size must be determined for an orchard to achieve good fruit size and maximum return. / AFRIKAANSE OPSOMMING: Die handhawing van konstante, hoë opbrengste in „Abate Fetel‟ en „Forelle‟ boorde in Suid-Afrika is 'n uitdaging. Produktiwiteit in hierdie boorde kan verhoog word deur vrugset en vruggrootte te verbeter. Vruggrootte is 'n belangrike bemarkings- en kwaliteitsparameter en het 'n betekenisvolle effek op die ekonomiese waarde van vrugte. 'n Verskeidenheid protokolle om vrugset te verbeter word deur Suid-Afrikaanse produsente gevolg, maar hierdie protokolle is nog nie goed nagevors nie. Verskillende kombinasies van plantgroeireguleerders insluitend gibberelliensuur (GA3), gibberellien 4+7 (GA4+7), GA4+7 in kombinasie met 6-bensieladenien (6-BA), aminoetoksievinielglisien (AVG) en prohexadioon-kalsium (P-Ca) in kombinasie met stamringelering is aan „Forelle‟ en „Abate Fetel‟ bome gedurende blomtyd toegedien om die beste vrugsetstrategie te bepaal. Alle plantgroeireguleerdes wat toegedien is het vrugset verbeter relatief tot 'n onbehandelde kontrole oor twee opeenvolgende seisoene, maar GA3 en P-Ca het die aantal blomme in die daaropvolgende seisoen verlaag en AVG het kleiner vruggrootte gelewer relatief tot alle ander behandelings. Dit is wel bekend dat die toediening van sintetiese sitokiniene vruggrootte verbeter deur die stimulering en bevordering van seldeling in vrugte wanneer dit in die regte groeifase toegedien word. Die kombinasie van P-Ca en GA4+7 was suksesvol om vruggrootte te verbeter toe dit aan Japanese pere (Pyrus pyrifolia Nakai) en „Bing‟ kersies toegedien is. Hierdie kombinasie van GA4+7 en P-Ca is geëvalueer en gekombineer met 6-BA-behandelings op die Europese peer (Pyrus communis L.) kultivars, Forelle en Abate Fetel, om te bepaal of dieselfde effek op vruggrootte bereik kan word onder Suid-Afrikaanse groei kondisies. Op beide „Forelle‟ en „Abate Fetel‟ het die kombinasies van GA4+7 en P-Ca vruggrootte verbeter, maar dit was meer opmerklik in die geval van „Abate Fetel‟. Die groeireguleerders N-feniel-N‟ -1,2,3-thiadiazol-5-ylurea (TDZ), N (2-chloro-4-piridiel)-N‟ -fenielurea (CPPU), 6-BA en 2,4- dichloorfenoksieasynsuur (2,4-D) het vruggrootte verbeter in „Coscia‟ en „Spadona‟ pere in Israel. Hierdie plantgroeireguleerders is toegedien aan „Forelle‟ en „Abate Fetel‟ om vas te stel of dieselfde effek verkry kon word. Nie enige van die sintetiese sitokiniene wat toegedien is het 'n betekenisvolle effek op die verbetering van vruggrootte in hierdie twee kultivars oor twee opeenvolgende seisoene getoon nie, alhoewel 6-BA die verbetering van blom in die daaropvolgende seisoen tot gevolg gehad en 2,4-D vrugset verbeter het. Die stadium waar seldeling in „Forelle‟ en „Abate Fetel‟ eindig is vasgestel as 34 en 45 dae na volblom, onderskeidelik, wat in die toekoms gebruik kan word om die beplanning en tydsberekening van vruggrootte behandelings te verbeter. Na verskeie vrugset en vruggroote verbeterings proewe, kan aanbeveel word dat GA4+7 of AVG gebruik kan word om vrugset in „Forelle‟ en „Abate Fetel‟ te verbeter, afhangende van die vrugset geskiedenis van die boord. Resultate van vruggrootte verbeterings proewe het gevarieër en beklemtoon net weer die feit dat 'n balans tussen opbrengs en vruggrootte bepaal moet word om optimale vruggrootte te handhaaf en so hoë winste te verseker. / SAAPPA

Orientador : Elizabeth Orika Ono / Banca: João Domingos Rodrigues / Banca: Vandeir Francisco Guimarães / Banca: Manoel Abilio de Queiroz / Banca: Silvio José Bicudo / Resumo: Tratamentos com reguladores vegetais foram estudados em plantas de soja (Glycine max (L.) Merrill cv. BRS-184) para avaliar o teor de clorofila das folhas, a altura da planta, o número de ramificações e altura de vagens. O experimento foi conduzido em casa de vegetação do Departamento de Botânica do Instituto de Biociências de Botucatu - UNESP. O delineamento experimental utilizado foi inteiramente casualizado, com três repetições e oito tratamentos (testemunha; GA3 100 mg L-1; BAP 100 mg L-1; IBA 100 mg L-1; Stimulate® (IBA+GA3+Cinetina) 20 mL L-1; cloreto de mepiquat 100 mg L-1; cloreto de mepiquat 100 mg L-1+BAP 100 mg L-1+IBA 100 mg L-1 e ethephon 600 mg L-1. Os tratamentos foram aplicados três vezes, espaçados em 30 dias durante o ciclo da planta a partir do 43º dia e foram realizadas seis avaliações espaçados em 13 dias. Os tratamentos com BAP, ethephon e cloreto de mepiquat + IBA + BAP mantiveram o teor de clorofila nas folhas alto até o final do ciclo da planta. A altura de plantas foi menor que a testemunha em todos os tratamentos a partir de 90 dias após a semeadura, com exceção do tratamento com GA3, que manteve a altura de plantas superior durante todo ciclo da cultura. As ramificações das plantas foram incrementadas pelo tratamento com ethephon, que apresentou, a altura da primeira vagem inferior à testemunha. No tratamento com GA3, a altura da primeira vagem foi superior. / Abstract: Treatments with plant growth regulators were studied in soybean plants (Glycine max (L.) Merrill cv. BRS-184) to assess the leaf chlorophyll content, the ramification number and the height of the pods. The experiment has been carried out at the greenhouse of the Botanic Department, Bioscience Institute, University of the Sao Paulo State - UNESP, campus of Rubiao Junior, Botucatu, Brazil. The used experimental design delineation was completely randomized block with three replications and eight treatments (control; GA3 100 mg L-1; BAP 100 mg L-1; IBA 100 mg L-1; Stimulate® (IBA+GA3+Cinetin) 20 mL L-1; mepiquat chloride 100 mg L-1; mepiquat chloride 100 mg L-1+BAP 100 mg L-1+IBA 100 mg L-1 and ethephon 600 mg L-1. The treatments were applied three times every 30 days during the plant cycle after 43 days and six evaluations have been made every 13 days. The treatments with BAP, ethephon and mepiquat chloride + IBA + BAP maintained the high chlorophyll content until the end of the plant cycle. The height of the plants was lower than the control in all treatments after the 90th day of sowing, excepting the treatment with GA3, which maintained the height of the plants during the cycle of cultivation. The plant stems were increased by the ethephon treatment; however, the height of the first pod was the lowest in this treatment and the highest in the treatment with GA3. / Doutor

The effects of hormonal chemicals and different genotypes on fruit growth of greenhouse-grown tomatoes (Lycopersicon esculentum Mill.) were examined. Continuous root application of 10nM N⁶-benzylaminopurine in Hoagland's nutrient solution to tomato seedlings of 'Fireball' and 'Red Cherry' significantly delayed anthesis of 'Fireball', but not 'Red Cherry'. Ovary diameter at anthesis, final fruit diameter, and fruit weight of both cultivars were unaffected. Irrespective of treatments, a significant positive correlation was obtained between ovary diameter at anthesis and final fruit diameter. A single foliar application of 0.25mM or 0.37mM β-na-phthoxyaceticacid (βNOA) at the appearance of the first in florescence of ‘Fireball' significantly increased ovary diameter at anthesis, but had no effect on final fruit diameter. Flowers on the second inflorescence of tomato plants treated with 0.37mM βNOA had smaller ovary sizes at anthesis than those of untreated plants. Application of 0.125mM βNOA, and 1µM, 10µM, and 100µM gibberellin A₃ had no significant effect on ovary diameter at anthesis or final fruit diameter. A significant positive correlation was also shown between ovary diameter at anthesis and final fruit diameter of βNOA treated plants. Among the twelve genotypes tested, significant correlations between ovary diameter at anthesis and final fruit diameter were found for 'Fireball', 'Michigan/Ohio Hybrid', and 'New Yorker'. The remaining genotypes showed no significant correlations between ovary diameter at anthesis and final fruit diameter. The average ovary diameter at anthesis (of all the genotypes) was significantly correlated with final fruit diameter, fruit weight, and locule number. / Master of Science

The relationship between porcine growth hormone (pGH) and insulin-like growth factor-I (IGF-I) in swine was investigated. IGF-I levels were measured by radioimmunoassay (RIA) with an antisera specific for human IGF-I after ultrafiltration of acidified samples. Ultrafiltration quantitatively separated carrier proteins and IGF-I. Failure to separate these species interfered with the RIA. Using this assay, swine chronically treated with pGH had 2.6-fold higher sera levels of IGF-I than controls, whereas, serum IGF-I from a hypophysectomized animal was only 4% that of normal animals. The ultrafiltration procedure was incorporated into a protocol to measure IGF-I in sera from neonatal swine treated with pGH (5O ug •kg BWt⁻¹•d⁻¹). Treatment of neonatal pigs with pGH for one or two weeks elevated pGH in sera, but did not significantly affect either growth or serum IGF-I concentrations. Preliminary studies were performed to determine if neonatal swine hepatocytes secreted IGF-I in vitro. Results indicated that neonatal hepatocytes synthesized limited quantities of IGF-I that approached the detection limits of the RIA. Furthermore, pGH did not stimulate hepatocyte IGF-I synthesis in vitro or in vivo. Neonatal hepatocytes synthesized a protein species that bound labeled IGF-I and had a molecular weight similar to a carrier protein in swine serum. Estimation of the rate of carrier protein synthesis suggested that IGF-I and carrier proteins are coordinately regulated in isolated neonatal hepatocytes. These results suggest that IGF-I is not inducible in the neonatal pig by GH therapy and that growth in neonatal swine is either maximal or GR-independent. / M.S.

Creeping Bentgrass (Agrostis stolonifera var. palustris (Huds.) Farw.) is the most widely used cool-season turf grass used for putting greens in North America. Frequently it becomes invaded with a persistent weed, annual bluegrass (Poa annua L.). Studies were conducted on a predominately annual bluegrass area managed as a putting green to attempt to quantify the impacts of plant growth regulator, seeding rate" and season on the success of introducing creeping bentgrass. Also, the impact of plant growth regulating substances on creeping bentgrass overall quality and seasonal rootmass production was evaluated. It was observed that creeping bentgrass does not become well established when overseeded into annual bluegrass regardless of plant growth regulator applications or season. Additionally 1I plant growth regulator application, following seedling emergence reduced creeping bentgrass seedling populations. Competition from established annual bluegrass and close frequent cutting were deemed reasons for lack of creeping bentgrass establishment success. Creeping bentgrass turf was maintained at a high level of quality with plant growth regulating substances. The use of the plant growth regulator trinexapac-ethyI reduced clipping production and was not detrimental to root production. Propiconizole application increased clippings and controlled Sclerotinia dollarspot. The application of a proprietary biostimulator material (3D) enhanced creeping bentgrass green color and generally increased rootmass over untreated turf. / Master of Science