Plant growth regulator(s) (PGR) can be used as lodging inhibitors and/or yield promoters for spring barley (Hordeum vulgare L.). From 1987 to 1990 four field experiments were conducted to monitor barley main-stem apical development and to determine the effects of chlormequat (CCC) and ethephon on the development, physiology and yield of spring barley. Our data provide a description of barley apical development and the general pattern of leaf and spikelet primordium production under field conditions. In general, PGR treatment reduced the apical dominance of dominant sinks allowing the survival and greater development of more subordinate sinks. Early application of either CCC or ethephon retarded development of the main-stem apex from shortly after application to the awn elongation stage and reduced the number of aborted spikelet primordia, thus increasing the potential number of grains per spike and sometimes grain yield. Ethephon applied at ZGS 39 reduced plant height and lodging. Early application (ZGS 30) of ethephon, alone or in combination with CCC increased the number of spikes m$ sp{-2},$ but not grain yield. The number of spike-bearing shoots per unit area or per plant was increased by early PGR treatment, primarily by enhancement of tiller number rather than tiller survival. Early application of CCC or ethephon to spring barley is not justified, and caution must be taken when using ethephon at the currently recommended rate and stage for lodging control. Post-anthesis application of ethephon can efficiently enhance grain fill and yield of spring barley.

The effect of preharvest foliar applications of ethephon and postharvest curing on baked sweet potatoes (Ipomoea batata) were analyzed. Ethylene had negative effects on appearance of baked roots while curing increased the total phenolics in sweet potatoes. Panelists preferred the non-ethylene treated and green or cured over ethylene treated sweet potatoes with respect to texture, color and flavor. No differences in chemical or color properties were found between treatments. The effect of curing time (0, 7, 14 days) on baked sweet potatoes was studied. Curing caused more browning on flesh of sweet potatoes. Moreover, panelists preferred the texture of the green over the cured roots but did not find any differences in flavor sensory quality. The effect of hot water treatment on sprouting and spoilage of cured sweet potatoes was investigated. The most effective treatment was at 53-56 °C for less than 10 min, resulting in less than 60% (control=80%).

No description available.

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

Os vegetais possuem metabólitos endógenos circulantes nos tecidos, que não necessariamente possuem função nutricional, mas atuam na regulação do crescimento e do desenvolvimento, os hormônios vegetais. Estes, quando utilizados exogenamente, permitem ações planejadas no crescimento das plantas. Igualmente, análogos sintéticos com ação semelhante vêm sendo utilizados na agricultura com o mesmo objetivo. No entanto, o efeito destes reguladores vegetais é variável entre as espécies e em suas fases fenológicas, com necessidade de estudos especificos que propiciem respostas adequadas aos objetivos de sua aplicação. Da mesma forma, encontramos também moléculas capazes de atuar na produção endógena de hormônios, limitando ou induzindo sua produção, afetando os processos de crescimento e desenvolvimento vegetal. A aplicação de tais substâncias na agricultura pode ser benéfica no controle do crescimento vegetal, revertendo a energia produzida pela fotossíntese para a produção dos cultivos. Diversos cultivos, incluindo os de cereais, tendem à um crescimento vegetativo exagerado com o incremento do uso de fertilizantes, causando quedas de produtividade e problemas na colheita devido ao acamamento das plantas. Diante disso, o presente estudo tem como objetivo avaliar as alterações morfológicas e fisiológicas do uso de reguladores vegetais na cultura do trigo (Triticum aestivum L.) e da cevada (Hordeum vulgare L.), visando redução do porte das plantas sem alterações ou com incremento de produção. Os experimentos foram desenvolvidos com ambas espécies de cereais, semeadas em vasos. As aplicações dos tratamentos foram realizadas no início da fase de alongamento do colmo. Nos experimentos, foram avaliados os efeitos da pulverização foliar de diferentes reguladores vegetais que restringem a síntese de giberelina na planta: ácido abscísico (ABA), etil trinexpac (Moddus), daminozide (SADH), ethephon (Ethrel) e cloreto de clormequat (CCC). Foram avaliadas variáveis relacionadas ao retardamento do crescimento vegetativo e à produção de carboidratos, assim como a produção das plantas tratadas, tais como: altura das plantas, índice SPAD, transpiração, condutância estomática e massa seca do caule e espigas. Os dados obtidos foram submetidos à análise de variância e quando significativos, os tratamentos foram comparados pelo teste de Tukey ao nível de 5% de probabilidade. A pulverização de ABA, SADH e Ethrel diminuiu significativamente a massa seca do colmo e promoveu retardamento do crescimento, no entanto, a aplicação de ABA aumentou significativamente o índice de colheita, assim como a massa seca dos grãos. Tratamentos com duas pulverizações de ABA 24 g L-1, com uma semana de intervalo restringiu o alongamento da planta, melhorando a arquitetura da mesma, o teor de clorofila e as trocas gasosas, nas culturas de trigo e cevada, estimulando incremento de 23% na massa seca dos grãos de trigo e de 33% em cevada; assim sendo, a aplicação deste retardante de crescimento pode ser considerada para ser utilizada em lavouras de cereais. / Plant tissues contain circulating endogenous metabolites which not necessarily play nutritional function but can regulate growth, plant hormones, that can be also exogenously applied for planned effects in plant growth. These molecules when sprayed on plants allow desirable effects on the plant growth. Moreover, synthetic analogues with similar action have been used in agriculture for the same purpose. However, the effect of growth regulators is variable among species and their phoenological stages, requiring specific studies that provide appropriate responses to their application. Similarly, there are also capable of acting on endogenous hormone production, limiting or stimulating their biosynthesis and consequently affecting the processes of growth and plant development. The application of such molecules in agriculture can be beneficial in controlling the plant growth, reversing the energy produced by photosynthesis for that growth to agronomic yield of crops. Several crops, including cereals, tend to respond with excessive vegetative growth to the increase of fertilizer application causing productivity decreases and damages to the crop due to the plant lodging. Thus, the present study was carried out to evaluate the morphological and physiological changes by the use of plant growth regulators on wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), aiming the reduction of the plant size and increases of productivity. The experiments were conducted with both cereal species sown in pots. The applications of the treatments were performed at the beginning of stem elongation stage The effects of foliar application of different plant growth regulators that restrict the gibberellin synthesis in the plant were evaluated: Abscisic acid (ABA), trinexapac-ethyl (Moddus), Daminozide (SADH), Ethephon (Ethrel), and chlormequat chloride (CCC). The following variables were measured: plant height, SPAD index (indirect chlorophyll content), transpiration, stomatal conductance, and dry mass of stems and spikelets. The data were analyzed by the Tukey test at 5% probability level. The spray with ABA, SADH, and Ethrel decreased significantly the dry mass of the stem and promoted growth retardation (plant height). However, the application of ABA increased significantly the harvest index, as well as the dry mass of the grains. Treatments with two sprays of ABA (24 g L-1), with an interval of a week restricted the plant growth in height improving the architecture thereof, chlorophyll content, and gas exchange, resulting in an increment of 23% and 33% in dry matter of grains of wheat and barley, respectively. Therefore, the application of ABA may be considered as an alternative for improving the productivity of cereal crops.

Os vegetais possuem metabólitos endógenos circulantes nos tecidos, que não necessariamente possuem função nutricional, mas atuam na regulação do crescimento e do desenvolvimento, os hormônios vegetais. Estes, quando utilizados exogenamente, permitem ações planejadas no crescimento das plantas. Igualmente, análogos sintéticos com ação semelhante vêm sendo utilizados na agricultura com o mesmo objetivo. No entanto, o efeito destes reguladores vegetais é variável entre as espécies e em suas fases fenológicas, com necessidade de estudos especificos que propiciem respostas adequadas aos objetivos de sua aplicação. Da mesma forma, encontramos também moléculas capazes de atuar na produção endógena de hormônios, limitando ou induzindo sua produção, afetando os processos de crescimento e desenvolvimento vegetal. A aplicação de tais substâncias na agricultura pode ser benéfica no controle do crescimento vegetal, revertendo a energia produzida pela fotossíntese para a produção dos cultivos. Diversos cultivos, incluindo os de cereais, tendem à um crescimento vegetativo exagerado com o incremento do uso de fertilizantes, causando quedas de produtividade e problemas na colheita devido ao acamamento das plantas. Diante disso, o presente estudo tem como objetivo avaliar as alterações morfológicas e fisiológicas do uso de reguladores vegetais na cultura do trigo (Triticum aestivum L.) e da cevada (Hordeum vulgare L.), visando redução do porte das plantas sem alterações ou com incremento de produção. Os experimentos foram desenvolvidos com ambas espécies de cereais, semeadas em vasos. As aplicações dos tratamentos foram realizadas no início da fase de alongamento do colmo. Nos experimentos, foram avaliados os efeitos da pulverização foliar de diferentes reguladores vegetais que restringem a síntese de giberelina na planta: ácido abscísico (ABA), etil trinexpac (Moddus), daminozide (SADH), ethephon (Ethrel) e cloreto de clormequat (CCC). Foram avaliadas variáveis relacionadas ao retardamento do crescimento vegetativo e à produção de carboidratos, assim como a produção das plantas tratadas, tais como: altura das plantas, índice SPAD, transpiração, condutância estomática e massa seca do caule e espigas. Os dados obtidos foram submetidos à análise de variância e quando significativos, os tratamentos foram comparados pelo teste de Tukey ao nível de 5% de probabilidade. A pulverização de ABA, SADH e Ethrel diminuiu significativamente a massa seca do colmo e promoveu retardamento do crescimento, no entanto, a aplicação de ABA aumentou significativamente o índice de colheita, assim como a massa seca dos grãos. Tratamentos com duas pulverizações de ABA 24 g L-1, com uma semana de intervalo restringiu o alongamento da planta, melhorando a arquitetura da mesma, o teor de clorofila e as trocas gasosas, nas culturas de trigo e cevada, estimulando incremento de 23% na massa seca dos grãos de trigo e de 33% em cevada; assim sendo, a aplicação deste retardante de crescimento pode ser considerada para ser utilizada em lavouras de cereais. / Plant tissues contain circulating endogenous metabolites which not necessarily play nutritional function but can regulate growth, plant hormones, that can be also exogenously applied for planned effects in plant growth. These molecules when sprayed on plants allow desirable effects on the plant growth. Moreover, synthetic analogues with similar action have been used in agriculture for the same purpose. However, the effect of growth regulators is variable among species and their phoenological stages, requiring specific studies that provide appropriate responses to their application. Similarly, there are also capable of acting on endogenous hormone production, limiting or stimulating their biosynthesis and consequently affecting the processes of growth and plant development. The application of such molecules in agriculture can be beneficial in controlling the plant growth, reversing the energy produced by photosynthesis for that growth to agronomic yield of crops. Several crops, including cereals, tend to respond with excessive vegetative growth to the increase of fertilizer application causing productivity decreases and damages to the crop due to the plant lodging. Thus, the present study was carried out to evaluate the morphological and physiological changes by the use of plant growth regulators on wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), aiming the reduction of the plant size and increases of productivity. The experiments were conducted with both cereal species sown in pots. The applications of the treatments were performed at the beginning of stem elongation stage The effects of foliar application of different plant growth regulators that restrict the gibberellin synthesis in the plant were evaluated: Abscisic acid (ABA), trinexapac-ethyl (Moddus), Daminozide (SADH), Ethephon (Ethrel), and chlormequat chloride (CCC). The following variables were measured: plant height, SPAD index (indirect chlorophyll content), transpiration, stomatal conductance, and dry mass of stems and spikelets. The data were analyzed by the Tukey test at 5% probability level. The spray with ABA, SADH, and Ethrel decreased significantly the dry mass of the stem and promoted growth retardation (plant height). However, the application of ABA increased significantly the harvest index, as well as the dry mass of the grains. Treatments with two sprays of ABA (24 g L-1), with an interval of a week restricted the plant growth in height improving the architecture thereof, chlorophyll content, and gas exchange, resulting in an increment of 23% and 33% in dry matter of grains of wheat and barley, respectively. Therefore, the application of ABA may be considered as an alternative for improving the productivity of cereal crops.

Made available in DSpace on 2017-07-10T17:37:44Z (GMT). No. of bitstreams: 1 Tatiana_Werle.pdf: 502997 bytes, checksum: a8ed05a8a76d34c68e008dc33707334a (MD5) Previous issue date: 2011-08-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In an attempt to induce the grapevines buds sprouting in mild winter regions, characterized by mild temperatures during the hibernal season, it becomes necessary the use of sprouting inducers. Considering the grapevines cultivation expansion in Western Paraná, the current study had as its aims to determine the optimal concentration of hydrogenated cyanamide, ethephon and Stimulate® bio-stimulant for the induction and uniformity of sprouting in Niagara Rosada cultivar, as well to indicate the most effective product in the uniformity sprouting inducing and which promotes improved productivity and fruits quality. The experiment was conducted in a commercial vineyard located in the municipality of Quatro Pontes, West of Paraná State. The experiment was carried out in outlined blocks in factorial scheme 3 X 5, totaling 15 treatments with four repetitions, and each plant was considered an experimental unit. The treatments consisted of the following concentrations: 0; 10 mL L-1; 20 mL L-1; 30 mL L-1 and 40 mL L-1 of hydrogenated cyanamide (H2CN2); 0 ; 2 L ha-1; 4 L ha-1; 6 L ha-1 and 8 L ha-1 of ethephon; 0; 5 mL L-1; 10 mL L-1; 15 mL L-1 and 20 mL L-1 Stimulate® bio-stimulant. The products application was made immediately after pruning, by spraying with backpack sprayer. After pruning, it was assessed the number of buds per plant, time to sprouting onset after application, number and percentage of sprouting per plant, production per plant, expected productivity, average weight of berries, number of berries per cluster, width of shoulder and berries, berries length, soluble solids content, titration total acidity, pH and ratio. Considering the conditions under which the experiment was conducted, one can conclude that: The concentration of hydrogenated cyanamide which showed higher percentage of 'Niagara Rosada' grapevine sprouted buds was the 20mL L-1; the ethephon concentration which provided the highest percentage of Niagara Rosada grapevine sprouted buds was the 8 L ha-1; the bio-stimulant concentration which provided the highest percentage of Niagara Rosada grapevine sprouted buds was the 5 mL L-1; the hydrogenated cyanamide provided the anticipation and uniformity of the Niagara Rosada grapevine sprouting. The buds spraying with hydrogenated cyanamide, ethephon and bio-stimulant resulted in no effect on the grapevine productivity and quality, cv. Niagara Rosada / Na tentativa de induzir a brotação das gemas de videiras em regiões de inverno ameno, caracterizado por temperaturas suaves durante a estação hibernal, torna-se necessário o emprego de indutores de brotação. Considerando a expansão do cultivo de videiras no Oeste do Paraná, o presente trabalho teve como objetivos verificar a concentração ideal de cianamida hidrogenada, ethephon e do bioestimulante Stimulate® para a indução e uniformização de brotação na cultivar Niagara Rosada, bem como indicar o produto mais eficiente na indução de uniformização de brotação e que promove melhor produtividade e qualidade de frutos. O experimento foi conduzido em vinhedo comercial localizado no município de Quatro Pontes, Oeste do Estado do Paraná. O experimento foi implantado em delineamento de blocos em esquema fatorial 3 X 5, totalizando 15 tratamentos com quatro repetições, sendo que cada planta foi considerada uma parcela experimental. Os tratamentos foram compostos pelas seguintes concentrações: 0; 10 mL L-1; 20 mL L-1; 30 mL L-1 e 40 mL L-1 de cianamida hidrogenada (H2CN2); 0; 2 L ha-1; 4 L ha-1; 6 L ha-1 e 8 L ha-1 de ethephon; 0; 5 mL L-1; 10 mL L-1; 15 mL L-1 e 20 mL L-1 de bioestimulante Stimulate®. A aplicação dos produtos foi feita imediatamente após a poda, através de pulverização com pulverizador costal. Após a poda avaliou-se o número de gemas por planta, tempo para início da brotação após a aplicação, número e porcentagem de brotações por planta, produção por planta, produtividade esperada, massa média das bagas, número de bagas por cacho, largura do ombro e das bagas, comprimento das bagas, teor de sólidos solúveis, acidez total titulável, pH e ratio. Considerando as condições em que foi conduzido o experimento pode-se concluir que: A concentração de cianamida hidrogenada que proporcionou maior porcentagem de gemas brotadas de videira Niagara Rosada foi a de 20 mL L-1; A concentração de ethephon que proporcionou maior porcentagem de gemas brotadas de videira Niagara Rosada foi a de 8 L ha-1; A concentração de bioestimulante que proporcionou maior porcentagem de gemas brotadas de videira Niagara Rosada foi a de 5 mL L-1; A cianamida hidrogenada proporcionou a antecipação e uniformização das brotações de videira Niagara Rosada. A pulverização das gemas com cianamida hidrogenada, ethephon e bioestimulante não resultou em efeito sobre a produtividade e qualidade de videira, cv. Niagara Rosada

Ethylene and carbohydrate deprivation were investigated as possible causes of bud abortion in Lilium longiflorum Thunb. Silver thiosulfate (STS) was investigated as an inhibitor of ethylene-induced abortion. Fourteen days of 92.5% irradiance reduction increased bud abortion when plants were exposed to 2.07 mM ethephon. Percent bud abortion was 39% and 60% for plants grown in full irradiance and reduced irradiance, respectively. Ethephon resulted in 54% abortion, regardless of irradiance at 4.15 mM. A 70% irradiance reduction for 14 days did not increase bud abortion when plants were treated with ethephon. STS was applied to plants at visible bud +2 weeks followed by ethephon application 2 days later. Bud abortion was reduced from 69 to 13% with 2 mM STS; the STS x ethephon interaction was significant. STS inhibited ethephon-induced bud abortion when applied at visible bud, 4 weeks prior to ethephon application; However, STS application at flower bud initiation did not prevent/reduce ethephon-induced bud abortion.

Ethephon treatment caused SPCP3 gene expression (Chen et al., 2006), reduction of chlorophyll content, decrease of Fv/Fm value, increase of H2O2 amount, and more cell death, and accelerated leaf senescence in detached sweet potato leave. Exogenous application of modulators such as reduced glutathione, EGTA or cycloheximide delay leaf senescence and cell death caused by ethephon. These data suggest that oxidative stress, calcium influx and de novo synthesized protein may influence ethephon-mediated leaf senescence and cell death. When ethephon induced leaf senescence and cell death, granulin-containing cysteine protease SPCP3 gene was induced. Transgenic Arabidopsis system was used to explore the possible physiological role and function of SPCP3. The results showed that ectopic expression of SPCP3 in transgenic Arabidopsis plants caused earlier flowering, less rosette leaves when flowering, higher yellowing silique percentage during harvest, and lower germination percentage than that in control. During drought treatment, transgenic plants also exhibited reduction of Fv/Fm value and relative water content, but an increase in H2O2 content and cell death. These data suggest that ecopic expression of SPCP3 caused altered developmental characteristics and drought stress sensitivity. Previous report suggests that granulin-like domain may play a role in regulating enzymatic activity of granulin-containing cysteine protease (Yamada et al., 2001). In this report we demonstrate that pre-removal of granulin-like domain of SPCP3 does not affect significantly drought stress sensitivity compared to full-length SPCP3 in transgenic Arabidopsis plants. Based on these data we conclude that oxidative stress, calcium influx, and de novo synthesized proteins may be involved in ethylene signaling leading to leaf senescence and SPCP3 gene expression in detached sweet potato leaves, and ectopic SPCP3 expression in transgenic Arabidopsis plants caused altered developmental characteristics and enhanced drought sensitivity. Granulin-like domain may have no significant influence on SPCP3-mediated effect on drought stress sensitivity.

A major sweet potato leaf-type catalase was detected and identified from fullyexpandedmature leaves using in-gel activity staining assay with native- andSDS-PAGEs. The putative catalase activity band was inhibited by a catalaseinhibitor 3-amino-1,2,4-triazole. The major leaf-type catalase activity wasoptimal over 8, and was significantly repressed by £]-mercaptoethanol. However,its activity was much less affected by temperature within the range of 5 to 450C.Temporal and spatial expression showed that it was specifically detected inleaves, but not in roots and stems. Its activity increased from the immature L2leaves, and reached the maximal at the fully-expanded mature L3 leaves, thenslightly decreased in partial yellowing senescent L4 leaves, and was almost notdetected in completely yellowing L5 leaves similar to folding unopenedimmature L1 leaves. The catalase level showed approximately inversecorrelation with the H2O2 amounts in leaves of different developmental stages.Dark and ethephon, an ethylene-releasing compound, also temporarily enhancedthe catalase activities from 6 h to 24 h, however, the enhanced activitydecreased from 24 h to 48 h in detached leaves after treatment. The catalaselevel also showed approximately negative correlation with the H2O2 amounts intreated leaves. The major leaf-type catalase activity was repressed by EGTA,and the repression can be reversed by exogenous CaCl2. The major leaf-typecatalase activity was also repressed by calmodulin inhibitor chlorpromazine,and the repression can be reversed by exogenous purified SPCAM calmodulinfusion protein. Chlorpromazine-treated leaves also elevated H2O2 amount.Based on these data we conclude that a major leaf-type catalase with maximalactivity in L3 leaf was identified in sweet potato. Its activity was temporarilyenhanced by dark and ethephon, and was modulated by external calcium ion(Ca2+) and calmodulin. A possible physiological role and function in associationwith cellular H2O2 homeostasis in cope with developmental and environmentalcues in sweet potato leaves is suggested.