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Grown for its distinctive foliage, Strobilanthes dyerianus is a popular bedding and container plant. A problem in production is that over-wintered stock plants often flower. Once the plant becomes reproductive, stem elongation slows and floral buds arise from every node, rendering the plants useless for propagation. The objectives of this research were to examine the effectiveness of manipulating environmental factors and the application of ethephon on preventing floral bud initiation, as well as determine optimal nitrogen rate for stock plant culture. The first experiment was performed in a glass greenhouse and ran 11 weeks, utilizing 8 h, 10 h, 12 h and a 4 h night interruption photoperiod treatments to determine critical photoperiod. None of the photoperiod treatments were significant for inhibiting flowering and there was a positive correlation between plant size and flowering. A second experiment was performed in growth chambers to create three photoperiods (8 h, 12 h and 16 h) with two temperature regimes (24C day/ 21C night and 17C day/ 14C night) for a total of six treatments. Neither photoperiod nor temperature inhibited bud initiation, and there was no correlation between plant size and flowering. The third experiment examined potential use of ethephon to maintain vegetative plants. Six rates of ethephon (0, 150, 300, 450, 600 or 750 mg·Lˉ¹) were applied at three frequencies (weekly, biweekly and monthly) over an eleven week period. Floral initiation was not totally inhibited, but flowering was highly correlated to plant size. Additionally, plant growth response to nitrogen was examined to determine the optimal rate for stock plant production. Plants were treated with 0, 100, 200, 300 or 400 mg·Lˉ¹ N from a 15 N – 2.2 P – 12.4 K fertilizer at each irrigation for eight weeks. There were no differences among plant quality ratings for plants receiving 100, 200, 300 or 400 mg·Lˉ¹ N, and plants grown with 200 mg·Lˉ¹ N had the largest leaf area and shoot dry weight. / Master of Science

Made available in DSpace on 2014-06-11T19:26:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-02Bitstream added on 2014-06-13T20:15:31Z : No. of bitstreams: 1 pantano_sc_me_botfca.pdf: 132910 bytes, checksum: c18c16187c2997e5f2fe00117f2e895a (MD5) / O experimento foi conduzido em um vinhedo comercial de uva 'Rubi' com seis anos de idade, localizado no município de Jales-SP durante os meses de agosto e setembro de 2001, com o objetivo de avaliar os efeitos de níveis e épocas de aplicação de etefon sobre a coloração e a qualidade dos frutos da uva ‘Rubi’. Os tratamentos consistiram da combinação entre duas épocas de aplicação e cinco concentrações de etefon (sem aplicação, 60, 120, 180 e 240mg.L-1) .O delineamento experimental utilizado foi inteiramente casualizado, em esquema fatorial 2x5. As características avaliadas foram: a) cor da baga, utilizando-se do sistema “L”, “a” e “b”; b) croma; c) massa média da baga; d) sólidos solúveis totais; e) acidez total titulável; f) textura; g) porcentagem de bagas verdes e i) umidade da ráquis. Conclui-se que o etefon melhorou a coloração das bagas, sem alterar a qualidade dos frutos e não houve efeito das épocas de aplicação. / The experiment was carried in a commercial vineyard of grape ' Rubi' with six years age, located in Jales-SP, Brazil, in the period of August to September, 2001. It had as aim to evaluated the effect of ethephon levels and moments application on coloration and quality of fruits of grape 'Rubi'. The treatments consisted of the combination among two moments of application and five ethephon concentrations (without application, 60, 120, 180 and 240mg.L- 1) .The experimental design was entirely casualized ,at factorial outline 2x5. The appraised characteristics were: the) color of the berry, being used of the system L , the and b ; b) it chromes; c) I weigh medium of the berry; d) total soluble solids; and) total titulable acidity; f) texture; g) percentage of green berry and i) humidity of the rachis. The results showed that the ethephon increased the coloration of the berry, did not alter the quality of the fruits, and there was no effect of the moments of application.

The primary objectives of this research are to analyze the effects plant growth regulators and pinching practices have on the growth habit of Penstemon x mexicali Pikes Peak Purple and Red Rocks and to produce more marketable containerized Penstemon. A preliminary study analyzed the effects branching agent PGRs had on Pikes Peak Purple. We found that the PGRs benzyladenine and ethephon were successful at producing more branches than the untreated control when the plants were considered finished in the container. Another group of PGRs known as growth retardants were also evaluated on Pikes Peak Purple. Both high and low rates of foliar applications of paclobutrazol or uniconazole resulted in growth control of the crop. Liner drench or soak applications of paclobutrazol were the most effective at reducing growth but resulted in over-regulated and stunted plants. A separate study focused on the combination of branching agents and pinching practices on Pikes Peak Purple. Both pinching and the application of branching agents improved overall plant quality until the stage of flower initiation where further growth regulation was needed. Based on the results of the previous experiments, we conducted a study combining branching agents and growth retardants on Pikes Peak Purple and Red Rocks. We found that the most marketable Pikes Peak Purple plants were produced with one pinch during the liner stage, two applications of benzyladenine, and one drench application of paclobutrazol. The most marketable Red Rocks plants were produced with one pinch during the liner stage, and two applications of ethephon. / Master of Science

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 Haze', Gaura lindheimeri Engelm. & A. Gray 'Siskiyou Pink', Lavandula × intermedia Emeric ex Loisel. 'Provence', Leucanthemum × superbum (Bergmans ex J.W. Ingram) Bergmans ex Kent. 'Snowcap', and Salvia × 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 Kippenberg' (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. 'Goodness Grows.' 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. 'Tutti Frutti' 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 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 'Autumn Joy,' Gaillardia aristata Pursh 'Gallo Red,' Phlox paniculata L. 'Bright Eyes,' Nepeta racemosa Lam. 'Walker's Low,' Delosperma NE Br. 'Table Mountain,' and Achillea L. 'Moonshine' 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

Orientador: Carlos Alexandre Costa Crusciol / Banca: Alan Rodrigo Panosso / Banca: Paulo Alexandre Monteiro de Figueiredo / Banca: Fernando Cesar Pattaro / Banca: Hideto Arizono / Resumo: O cultivo da cana-de-açúcar sofreu muitas mudanças nos últimos 15 anos. Extinção da queima, mecanização completa do plantio e colheita, expansão rumo a áreas de cerrado são apenas algumas delas. Entretanto, alguns velhos e bem conhecidos problemas permanecem presentes. Embora conhecido e extensamente estudado, o florescimento da cana-de-açúcar continua a causar perdas de produtividade. O método de controle mais utilizado envolve o uso de ethephon, o qual, apesar de conhecida eficiência, não raro tem seus resultados questionados, principalmente por uso inadequado. O objetivo do presente trabalho foi caracterizar as variáveis envolvidas no processo de florescimento que afetam a eficiência de seu controle pelo ethephon e propor estratégias de manejo que otimizem seus resultados. O trabalho foi realizado durante os anos de 2014 e 2016 em quatro regiões produtoras de cana-de-açúcar do centro-sul brasileiro e envolveu a avaliação do uso de ethephon em diferentes épocas de aplicação em três cultivares de cana-de-açúcar. Os melhores resultados foram obtidos com aplicações realizadas entre 20 dias antes à 5 dias após o início do período indutivo (P.I.). O ponto ótimo de controle ocorreu quando a aplicação foi realizada entre 9 a 6 dias antes do início de P.I. A menor intensidade de florescimento foi acompanhada dos maiores ganhos em produtividade (p<0,05), com média oscilando entre 12 a 16 % em relação à testemunha. Aplicações realizadas durante e após o término do P.I. apresentaram r... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Sugarcane growth in Brazil has undergone many changes in the last 15 years. Extinction of trash burning, complete mechanization of planting and harvesting, expansion to Cerrado areas are just a few of them. However, some old and well-known problems remain. Despite being widely studied; the sugarcane flowering continues to promote yield losses. The most used method of control is ethephon, despite known efficiency, often has its results questioned, mainly due to inadequate use. The aim of this work was to characterize the variables involved in the flowering process that affect the efficiency of its control by ethephon and to propose management strategies that optimize its results. The work was carried out during the years 2014 and 2016 in four sugarcane producing regions of Brazil and involved the evaluation of ethephon sprayed in different dates and cultivars. The best results were obtained in sprays carried out between 20 days before and 5 days after the beginning of the inductive period (I.P.). The optimal spraying date was about 9 to 6 days before I.P. The lower flowering intensity was accompanied by higher yield (p<0.05), ranging from 12 a 16% compared to the control. Spraying done during and after the I.P. showed a gradual reduction in the efficiency flowering control. However, there was delay in panicle emission and reduction in the intensity of adverse factors such as pith, with a mean reduction of 40% compared to the control. Although its lower yields, those spraying dates showed higher yield (p<0.05) than the control, with an average of 6%. The anticipation of the control (over 25 to 30 days) was also inefficient in the flowering control and with has lower yields than spraying done later, even, those ones done after the end of I.P. Pith intensity was related to flowering, but also to the time of panicle exposure in the field and, mainly, to the conditions of water restriction. The use of ... / Doutor

Made available in DSpace on 2017-07-25T19:29:48Z (GMT). No. of bitstreams: 1 Pamella Hilgemberg.pdf: 1006022 bytes, checksum: 658a9e23cc65477b9afe8672032cdf1a (MD5) Previous issue date: 2010-08-19 / A correct management with lower costs in the crop can make a difference when one considers the maximization of yield for area of wheat crop management techniques should be adjusted to provide the greater profitability for producers of wheat. The aim of this study was to evaluate the effect of growth regulators and plant densities in three wheat cultivars. The experiments were deployed Farm School Capão da Onça in 2008, winter season. The treatments were sowing densities (150, 300, 450, 600, 750 and 900 seeds m-2) and with or without the growth regulator trinexapac-ethyl, in cultivars BRS208 and OR1. In the cultivar Safira, the treatments were six sowing rates (150, 300, 450, 600, 750, 900 seeds m-2) and regulators, trinexapac-ethyl and cycocel & ethepon. In all experiments, the regulators were applied between 1˚ and 2 ˚ node visible. Increasing the plant population decreased the number of tillers per plant, leaf area per plant, n ˚ green leaves per plant mother and increased productivity for the cultivars safira and OR1. In the experiments did not observe the presence of lodging, even in the cultivar safira, more susceptible. To cultivate safira observed an effect of regulators in the length of flag leaf, and to cultivate OR1, trinexapac-ethyl affected the width of the flag leaf. In the cultivar safira saw the effect of regulators in the reduction in height, which occurred specifically in 2 ˚, 3˚ and 4˚ internodes. The use of growth regulators in the experiments gave a decrease of plant height, for and the cultivar safira, regulators contributed to higher productivity, which was not observed OR1 and BRS208. / Um manejo correto com custos menores na cultura pode fazer diferença quando se considera a maximização da produtividade por área da cultura do trigo. Assim, as técnicas de manejo devem ser ajustadas de forma a proporcionar maior lucratividade o aos produtores de trigo. O objetivo deste trabalho foi avaliar o efeito de reguladores de crescimento e de densidades de plantio em três cultivares de trigo. Os experimentos foram implantados da Fazenda Escola Capão da Onça, no ano de 2008, safra inverno. Os tratamentos foram seis densidades de semeadura (150, 300, 450, 600, 750 e 900 sementes m-2) e o uso ou não do regulador de crescimento trinexapac-ethyl, para as cultivares BRS208 e OR1. Para a cultivar Safira, os tratamentos foram seis densidades de semeadura (150, 300, 450, 600, 750 e 900 sementes m-2) e os reguladores trinexapac-ethyl e cycocel & ethepon. Em todos os experimentos os reguladores foram aplicados entre o 1˚ e 2˚ nó visível. O aumento da população de plantas diminuiu o número de perfilhos por planta, a área foliar por planta, n˚ de folhas verdes por planta mãe e aumentou a produtividade para as cultivares safira e OR1. Nos experimentos não foi observada a presença de acamamento, mesmo na cultivar Safira, mais suscetível. Para a cultivar Safira observou-se efeito dos reguladores no comprimento da folha bandeira, e para a cultivar OR1, o trinexapac-ethyl afetou a largura da folha bandeira. Para a cultivar safira verificou-se o efeito dos reguladores na diminuição de altura, que ocorreu mais especificamente no 2˚, 3˚ e 4˚ entrenós. O uso de reguladores de crescimento nos experimentos conferiu uma diminuição de altura das plantas, e para a cultivar safira, os reguladores promoveram maior produtividade, o que não ocorreu para OR1 e BRS208.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-05-26T13:09:56Z No. of bitstreams: 2 Dissertação - Patrícia Aparecida de Carvalho Felisberto - 2015.pdf: 5137723 bytes, checksum: 1a2d107b747e1e556b5cc29325451197 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-05-26T13:14:03Z (GMT) No. of bitstreams: 2 Dissertação - Patrícia Aparecida de Carvalho Felisberto - 2015.pdf: 5137723 bytes, checksum: 1a2d107b747e1e556b5cc29325451197 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-05-26T13:14:03Z (GMT). No. of bitstreams: 2 Dissertação - Patrícia Aparecida de Carvalho Felisberto - 2015.pdf: 5137723 bytes, checksum: 1a2d107b747e1e556b5cc29325451197 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In the field aerial application of sugarcane ripeners, spraying should reach its target without drifting occurs, avoiding contamination of surrounding crops. The aim of this research was to evaluate the effects of sugarcane ripeners simulated drift using sublethal rates in maize when applied to V4 and V8 stages of development. For this purpose were installed two trials on the Federal University of Goiás, Regional Jataí. Each plot contained 10 rows of SYN 7G17 maize hybrid. Each trial consisted of eight treatments established in design with randomized blocks where the treatments were arranged at factorial design of 2 x 4, plus one control treatment, with four replications. First factor corresponds to spraying at the V4 and V8 stages of maize and the second factor to sublethal rates of 3; 6; 9 to 12% of 475.2 g a.i. ha-1 ethephon (Trial I), 216.0 g a.e. ha-1 glyphosate (Trial II) and 15.0 g a.i. ha-1 sulfometuron methyl (Trial III). At 20 and 36 days after sowing, when the maize were in V4 and V8, respectively, applications of ripeners were performed.The phytotoxicity effects were noticeable in both stages at 7, 14, 21, 28 and 42 days after spraying only for Trial III. For glyphosate, the length and diameter of ear were reduced in size to both stages. Maize is sensitive to sublethal rates starting from 0.45 g a.i. ha-1 sulfometuron methyl in V4 and V8 stages of development. The lower grain yield was only to plants subjected to sublethal doses of sulfometuron methyl, being lower yield when drift occurs in the V8 stage of development compared to the V4 stage. / Na aplicação aérea de maturadores de cana-de-açúcar, a pulverização deve atingir o seu alvo sem que ocorra deriva, evitando a contaminação de culturas circunvizinhas. Objetivou-se com a pesquisa avaliar o efeito de subdoses de maturadores de cana-de-açúcar na cultura do milho quando aplicadas em estádios de desenvolvimento V4 e V8. Foram instalados três ensaios na Fazenda da Universidade Federal de Goiás, UFG, Regional Jataí. Cada parcela continha 10 linhas do híbrido de milho SYN 7G17. Cada ensaio foi constituído de oito tratamentos estabelecidos em delineamento com blocos casualizados em esquema fatorial 2 x 4 mais um tratamento controle (sem aplicação de maturador), com quatro repetições. O primeiro fator corresponde a aplicação nos estádios V4 e V8 da cultura do milho e o segundo fator às subdoses de 3; 6; 9 e 12% de 475,2 g i.a. ha-1 de ethephon (Ensaio I), 216,0 g e.a. ha-1 de glyphosate (Ensaio II) e 15,0 g i.a. ha-1 de sulfometuron methyl (Ensaio III). Aos 20 e aos 36 dias após a semeadura, quando as plantas de milho se encontravam em V4 e V8, respectivamente, foram realizadas as aplicações dos maturadores. Os efeitos de fitotoxicidade foram perceptíveis em ambos os estádios aos 7, 14, 21, 28 e 42 dias após a aplicação apenas para o Ensaio III. Para glyphosate, o comprimento e diâmetro de espigas foram afetados para ambos os estádios. A cultura do milho é sensível a subdoses a partir de 0,45 g i.a. ha-1 de sulfometuron methyl em estádios de desenvolvimento V4 e V8. A produtividade de grãos foi menor apenas para as plantas submetidas às subdoses de sulfometuron methyl, com menos efeito quando a deriva ocorre no estádio de desenvolvimento V8 em comparação ao estádio V4.

Ethylene has long been considered as the main plant growth regulator that plays a key role in the regulation of leaf senescence. In sweet potato, ethephon, an ethylene releasing compound, promoted leaf senescence and H2O2 elevation. These ethephon-mediated effects were alleviated or attenuated by exogenous reduced glutathione and ascorbic acid. Ethephon treatment gradually increased endogenous total and reduced glutathione and ascorbic acid levels in sweet potato detached leaves 3 days after treatment. The H2O2 amount, however, was also increased at 72 h after treatment. Sweet potato detached leaves pretreated with reduced glutathione did significantly increased endogenous total and reduced glutathione levels at 24 h and remarkably decreased H2O2 amount at 72 h after ethephon application compared to that of ethephon alone control. Ethephon caused quick elevation of a small H2O2 peak at about 4 h after application, and the enhancement was eliminated by reduced glutathione pretreatment in treated sweet potato leaves. Pretreatment of diphenylene iodonium (DPI), an NADPH oxidase inhibitor, also repressed leaf senescence and H2O2 elevation at day 3 after ethephon treatment in sweet potato detached leaves, and the attenuation was effective within the first 4 h after ethephon treatment. For senescence-associated gene expression, ethephon and L-buthionine sulfoximine (BSO), an endogenous glutathione synthase inhibitor, did induced asparaginyl endopeptidase (SPAE) and cysteine proteases (SPCP1, SPCP2 and SPCP3) gene expression and the activation was repressed by reduced glutathione pretreatment. Based on these data we conclude that ethephon treatment may cause quick elevation of a small H2O2 peak likely via the NADPH oxidase, which may function as a signal component leading to leaf senescence, H2O2 elevation and senescence-associated gene expression in sweet potato detached leaves. The rate of endogenous antioxidant such as reduced glutathione elevation is also important and affects leaf senescence, H2O2 elevation and senescence-associated gene expression in sweet potato leaves.