Made available in DSpace on 2016-01-26T18:56:31Z (GMT). No. of bitstreams: 1 Luciana Midori Takamori.pdf: 833111 bytes, checksum: 9cc8e066771c7d927c3b5a8b15bc398c (MD5) Previous issue date: 2014-11-05 / The establishment of an efficient methodology for regeneration in Urochloa spp via somatic embryogenesis is an essential step for genetic engineering works and to support the breeding programs of the signal grass. The aim of this study was to evaluate different concentrations of growth regulators on callus induction, somatic embryogenesis and plant regeneration of Urochloa spp. using mature seeds as the initial explant. Firstly, eight treatments were tested containing different concentrations (1, 2, 4 and 8 mg L-1) of 2,4-D or picloram, using Marandu cultivar. After, the same concentrations of picloram were tested for others genotypes: cultivars Xaraés and Piata of U. brizantha, U. decumbens cv. Basilisk, U. humidicola. cv. Llanero and U. ruziziensis cv. Ruziziensis. The experiments were conducted in a completely randomized design with four replications per treatment, and each replicate consisted of a petri dish containing 10 seeds each. The experiments were repeated three times. Seeds were sterilized in 5% NaOCl containing three drops of Tween 20, washed five times in sterile distilled water and inoculated onto MS medium containing the treatments described above. The experiments were maintained in growth chamber at 25 ° C ± 2 ° C in the dark, and sub-cultured every 14 days until the emergence of embryogenic calluses. To induce plant regeneration, these calluses were transferred to hormone-free MS medium for 14 days in indirect light followed by transfer to MS/2 medium containing 2 mg/L-BA in direct light with a photoperiod of 16 hours. The number of seeds that produced primary calluses, the number of calluses with shoots and the number of regenerated plants were analyzed in each treatment. To demonstrate embryogenic competence, the different calluses types were cyto-chemically analyzed by double staining with acetic carmine and Evans blue. There was no significant difference between concentration of 2,4D or picloram for production of primary calluses of U. brizantha Marandu ranging from 58.5% to 69.2%. Calluses induced under picloram showed the highest percentage of shoot formation differing significantly from those induced under 2.4D. The genotypes U. decumbens cv. Basilisk, U. brizantha cv. Marandu and Xaraés showed the significant highest number of regenerated plants at 1 mg/L picloram. Green and morphologically normal plants were regenerated and acclimatized, opening the possibility of using this protocol to obtain transgenic plants in Urochloa spp. / O estabelecimento de uma metodologia eficiente para regeneração in vitro de Urochloa spp. via embriogênese somática é essencial para trabalhos de manipulação genética e, para dar suporte ao melhoramento do capim braquiária. O objetivo deste trabalho foi avaliar diferentes concentrações de reguladores de crescimento na indução de calos, embriões somáticos e na regeneração de plantas de Urochloa spp., utilizando sementes maduras como explante inicial. Inicialmente, foram testados quatro tratamentos contendo 2,4-D ou picloram, nas concentrações de 1, 2, 4 e 8 mg/L usando a cultivar Marandu (1cultivar x 2 reguladores x 4 concentrações x 12 repetições). Posteriormente, as mesmas concentrações de picloram foram testadas para as cultivares Xaraés e Piatã de U. brizantha e para as espécies de U. decumbens cv. Basilisk, U. humidicola cv. Llanero e U. ruziziensis cv. Ruziziensis (6 cultivares x 1 regulador x 4 concentrações x 12 repetições). Os experimentos foram conduzidos em delineamento inteiramente casualizado, com quatro repetições por tratamento, sendo que cada repetição foi composta por uma placa contendo 10 sementes cada. Os experimentos foram repetidos três vezes. As sementes foram desinfestadas em NaOCl a 5% contendo três gotas de Tween 20, lavadas cinco vezes em água destilada esterilizada e inoculadas em meio MS contendo as diferentes concentrações dos reguladores de crescimento. Os experimentos foram mantidos em câmara de crescimento a 25 ºC ± 2 ºC, na ausência de luz, sendo sub-cultivados a cada 14 dias até o surgimento de calos embriogênicos. Estes calos foram transferidos para o meio MS sem adição de fitorreguladores por 14 dias, em luz indireta e, em seguida, transferidos para o meio MS/2 contendo 2 mg/L de BA, sob luz direta, com fotoperíodo de 16 horas para regeneração de plantas. Foram analisados o número de sementes que produziram calos primários, número de calos que produziram brotos e número de plantas regeneradas. Os diferentes tipos de calos produzidos foram avaliados citoquimicamente por meio da dupla coloração com Carmim acético e azul de Evans para certificar a competência embriogênica. Para a U. brizantha cv Marandu não houve diferença significativa entre os tratamentos para o percentual médio de sementes que produziram calos primários variando de 58,5% a 69,2%. Calos embriogênicos induzidos com o regulador de crescimento picloram certificaram o maior percentual de formação de brotos diferindo significativamente daqueles induzidos sob 2,4-D. O maior número de plantas regeneradas foi observado na concentração de 1 mg/L de picloram para os genótipos U. decumbens cv. Basilisk, U. brizantha cv. Marandu e Xaraés e não apresentando diferença significativa entre eles. Plantas verdes e morfologicamente normais foram regeneradas e aclimatizadas, abrindo a possibilidade do uso deste protocolo para obtenção de plantas transgênicas em Urochloa spp.

Made available in DSpace on 2016-01-26T18:56:31Z (GMT). No. of bitstreams: 1 Rafael Rebes Zilliani.pdf: 603873 bytes, checksum: 841c569299d71ab210698b9255ac75ba (MD5) Previous issue date: 2015-03-02 / Several environmental factors can alter the physiological processes of sugarcane plants, however, water deficit is the main factor limiting the productivity of this crop. The use of plant growth regulators can mitigate the effects of the drought, because these substances improve the regulation of physiological processes in the plant. In this context, the aim of this study was to evaluate the effects of a plant growth regulators solution (auxin, cytokinin and gibberellin) on the initial development and photosynthesis of sugarcane under water deficit. It was adopted a completely randomized 2 x 3 factorial design, two water regimes - control (100% of field capacity) and water deficit (20% of field capacity), and three doses of the bioregulators solution (0, 0.5 and 1.0 L h-1). The experimental plot consisted of plastic pots containing 12.0 kg of soil with one plant per pot of RB867515 and SP81-3250 cultivars, with ten replicates. The treatments with bioregulators solution was carried out with the commercial solution of plant growth regulators Stimulate® on stalks at planting and at 64 days after planting (DAP) by foliar application. Water deficit was initiated at 55 DAP and during this period were held biometric and physiological evaluations in plants. At 110 DAP biomass evaluation was performed. The drought reduced the relative water content of the plants, and all physiological parameters, maximum CO2 assimilation (Amax), stomatal conductance (Gs), maximum speed of Rubisco carboxylation and PEPCase enzymes (Vcmax and Vpmax) and, reduced plant growth and biomass production. However, plants that were treated with Stimulate® showed lower reduction in all physiological parameters, biometric and a smaller reduction in biomass when compared to plants not receiving treatment with the bioregulator solution. The bioregulators mainly stimulated the growth of the root system, which promoted greater absorption of water by plants and, consequently, better physiological performance under drought. The Stimulate® attenuated the effects of drought on physiological processes, promoting smaller reduction in Amax, Vcmax and Vpmax and also lower photochemical damage. This condition was responsible for the largest growth (height and leaf area) increasing the total biomass of plants (root, leaf and stem). / Vários fatores ambientais podem alterar os processos fisiológicos das plantas de cana-de-açúcar, porém o déficit hídrico é o principal fator que limita a produtividade desta cultura. O uso de reguladores vegetais pode atenuar os efeitos causados pelo déficit hídrico, em vista de que essas substâncias podem auxiliar na regulação dos processos fisiológicos da planta. Nesse contexto, o objetivo deste estudo foi avaliar os efeitos de uma solução de biorreguladores (auxina, citocinina e giberelina) sobre o desenvolvimento inicial e fotossíntese de cana-de-açúcar sob déficit hídrico. Foi adotado o delineamento inteiramente casualizado no esquema fatorial 2x3, sendo dois regimes hídricos, controle (100% da capacidade de campo) e déficit hídrico (20% da capacidade de campo) e três doses da solução de biorreguladores (0, 0,5 e 1,0 L ha-1). A parcela experimental foi constituída de vasos plásticos contendo 12,0 kg de solo com uma planta por vaso das cultivares RB867515 e SP81-3250, para cada tratamento utilizou-se dez repetições. Realizou-se o tratamento das plantas com a solução comercial de biorreguladores Stimulate® nos toletes no momento do plantio e aos 64 dias após o plantio (DAP) via aplicação foliar. O déficit hídrico foi iniciado aos 55 DAP e durante este período foram realizadas avaliações biométricas e fisiológicas nas plantas. Aos 110 DAP realizou-se a avalição de biomassa. O déficit hídrico reduziu o conteúdo relativo de água das plantas, bem como todos os parâmetros fisiológicos, assimilação máxima de CO2 (Amax), condutância estomática (Gs), velocidade máxima de carboxilação das enzimas Rubisco e PEPcase (Vcmax e Vpmax) e ainda, reduziu o crescimento das plantas e a produção de biomassa. No entanto, as plantas que foram tratadas com Stimulate® tiveram menor redução em todos os parâmetros fisiológicos, biométricos e menor redução na produção de biomassa quando comparadas as plantas que não receberam o tratamento com a solução de biorreguladores. Os biorreguladores estimularam principalmente o crescimento do sistema radicular, que promoveu maior absorção de água pelas plantas e, consequentemente, melhor desempenho fisiológico sob déficit hídrico. O Stimulate® atenuou os efeitos do déficit hídrico nos processos fisiológicos, promovendo menor redução em Amax, Vcmax e Vpmax e também menor dano fotoquímico. Essa condição foi responsável pelo maior crescimento (altura e área foliar) aumentando a produção de biomassa total das plantas (raiz, folhas e colmo).

Made available in DSpace on 2016-07-18T17:51:13Z (GMT). No. of bitstreams: 1 Luciana Midori Takamori.pdf: 833111 bytes, checksum: 9cc8e066771c7d927c3b5a8b15bc398c (MD5) Previous issue date: 2014-11-05 / The establishment of an efficient methodology for regeneration in Urochloa spp via somatic embryogenesis is an essential step for genetic engineering works and to support the breeding programs of the signal grass. The aim of this study was to evaluate different concentrations of growth regulators on callus induction, somatic embryogenesis and plant regeneration of Urochloa spp. using mature seeds as the initial explant. Firstly, eight treatments were tested containing different concentrations (1, 2, 4 and 8 mg L-1) of 2,4-D or picloram, using Marandu cultivar. After, the same concentrations of picloram were tested for others genotypes: cultivars Xaraés and Piata of U. brizantha, U. decumbens cv. Basilisk, U. humidicola. cv. Llanero and U. ruziziensis cv. Ruziziensis. The experiments were conducted in a completely randomized design with four replications per treatment, and each replicate consisted of a petri dish containing 10 seeds each. The experiments were repeated three times. Seeds were sterilized in 5% NaOCl containing three drops of Tween 20, washed five times in sterile distilled water and inoculated onto MS medium containing the treatments described above. The experiments were maintained in growth chamber at 25 ° C ± 2 ° C in the dark, and sub-cultured every 14 days until the emergence of embryogenic calluses. To induce plant regeneration, these calluses were transferred to hormone-free MS medium for 14 days in indirect light followed by transfer to MS/2 medium containing 2 mg/L-BA in direct light with a photoperiod of 16 hours. The number of seeds that produced primary calluses, the number of calluses with shoots and the number of regenerated plants were analyzed in each treatment. To demonstrate embryogenic competence, the different calluses types were cyto-chemically analyzed by double staining with acetic carmine and Evans blue. There was no significant difference between concentration of 2,4D or picloram for production of primary calluses of U. brizantha Marandu ranging from 58.5% to 69.2%. Calluses induced under picloram showed the highest percentage of shoot formation differing significantly from those induced under 2.4D. The genotypes U. decumbens cv. Basilisk, U. brizantha cv. Marandu and Xaraés showed the significant highest number of regenerated plants at 1 mg/L picloram. Green and morphologically normal plants were regenerated and acclimatized, opening the possibility of using this protocol to obtain transgenic plants in Urochloa spp. / O estabelecimento de uma metodologia eficiente para regeneração in vitro de Urochloa spp. via embriogênese somática é essencial para trabalhos de manipulação genética e, para dar suporte ao melhoramento do capim braquiária. O objetivo deste trabalho foi avaliar diferentes concentrações de reguladores de crescimento na indução de calos, embriões somáticos e na regeneração de plantas de Urochloa spp., utilizando sementes maduras como explante inicial. Inicialmente, foram testados quatro tratamentos contendo 2,4-D ou picloram, nas concentrações de 1, 2, 4 e 8 mg/L usando a cultivar Marandu (1cultivar x 2 reguladores x 4 concentrações x 12 repetições). Posteriormente, as mesmas concentrações de picloram foram testadas para as cultivares Xaraés e Piatã de U. brizantha e para as espécies de U. decumbens cv. Basilisk, U. humidicola cv. Llanero e U. ruziziensis cv. Ruziziensis (6 cultivares x 1 regulador x 4 concentrações x 12 repetições). Os experimentos foram conduzidos em delineamento inteiramente casualizado, com quatro repetições por tratamento, sendo que cada repetição foi composta por uma placa contendo 10 sementes cada. Os experimentos foram repetidos três vezes. As sementes foram desinfestadas em NaOCl a 5% contendo três gotas de Tween 20, lavadas cinco vezes em água destilada esterilizada e inoculadas em meio MS contendo as diferentes concentrações dos reguladores de crescimento. Os experimentos foram mantidos em câmara de crescimento a 25 ºC ± 2 ºC, na ausência de luz, sendo sub-cultivados a cada 14 dias até o surgimento de calos embriogênicos. Estes calos foram transferidos para o meio MS sem adição de fitorreguladores por 14 dias, em luz indireta e, em seguida, transferidos para o meio MS/2 contendo 2 mg/L de BA, sob luz direta, com fotoperíodo de 16 horas para regeneração de plantas. Foram analisados o número de sementes que produziram calos primários, número de calos que produziram brotos e número de plantas regeneradas. Os diferentes tipos de calos produzidos foram avaliados citoquimicamente por meio da dupla coloração com Carmim acético e azul de Evans para certificar a competência embriogênica. Para a U. brizantha cv Marandu não houve diferença significativa entre os tratamentos para o percentual médio de sementes que produziram calos primários variando de 58,5% a 69,2%. Calos embriogênicos induzidos com o regulador de crescimento picloram certificaram o maior percentual de formação de brotos diferindo significativamente daqueles induzidos sob 2,4-D. O maior número de plantas regeneradas foi observado na concentração de 1 mg/L de picloram para os genótipos U. decumbens cv. Basilisk, U. brizantha cv. Marandu e Xaraés e não apresentando diferença significativa entre eles. Plantas verdes e morfologicamente normais foram regeneradas e aclimatizadas, abrindo a possibilidade do uso deste protocolo para obtenção de plantas transgênicas em Urochloa spp.

Made available in DSpace on 2016-07-18T17:51:13Z (GMT). No. of bitstreams: 1 Rafael Rebes Zilliani.pdf: 603873 bytes, checksum: 841c569299d71ab210698b9255ac75ba (MD5) Previous issue date: 2015-03-02 / Several environmental factors can alter the physiological processes of sugarcane plants, however, water deficit is the main factor limiting the productivity of this crop. The use of plant growth regulators can mitigate the effects of the drought, because these substances improve the regulation of physiological processes in the plant. In this context, the aim of this study was to evaluate the effects of a plant growth regulators solution (auxin, cytokinin and gibberellin) on the initial development and photosynthesis of sugarcane under water deficit. It was adopted a completely randomized 2 x 3 factorial design, two water regimes - control (100% of field capacity) and water deficit (20% of field capacity), and three doses of the bioregulators solution (0, 0.5 and 1.0 L h-1). The experimental plot consisted of plastic pots containing 12.0 kg of soil with one plant per pot of RB867515 and SP81-3250 cultivars, with ten replicates. The treatments with bioregulators solution was carried out with the commercial solution of plant growth regulators Stimulate® on stalks at planting and at 64 days after planting (DAP) by foliar application. Water deficit was initiated at 55 DAP and during this period were held biometric and physiological evaluations in plants. At 110 DAP biomass evaluation was performed. The drought reduced the relative water content of the plants, and all physiological parameters, maximum CO2 assimilation (Amax), stomatal conductance (Gs), maximum speed of Rubisco carboxylation and PEPCase enzymes (Vcmax and Vpmax) and, reduced plant growth and biomass production. However, plants that were treated with Stimulate® showed lower reduction in all physiological parameters, biometric and a smaller reduction in biomass when compared to plants not receiving treatment with the bioregulator solution. The bioregulators mainly stimulated the growth of the root system, which promoted greater absorption of water by plants and, consequently, better physiological performance under drought. The Stimulate® attenuated the effects of drought on physiological processes, promoting smaller reduction in Amax, Vcmax and Vpmax and also lower photochemical damage. This condition was responsible for the largest growth (height and leaf area) increasing the total biomass of plants (root, leaf and stem). / Vários fatores ambientais podem alterar os processos fisiológicos das plantas de cana-de-açúcar, porém o déficit hídrico é o principal fator que limita a produtividade desta cultura. O uso de reguladores vegetais pode atenuar os efeitos causados pelo déficit hídrico, em vista de que essas substâncias podem auxiliar na regulação dos processos fisiológicos da planta. Nesse contexto, o objetivo deste estudo foi avaliar os efeitos de uma solução de biorreguladores (auxina, citocinina e giberelina) sobre o desenvolvimento inicial e fotossíntese de cana-de-açúcar sob déficit hídrico. Foi adotado o delineamento inteiramente casualizado no esquema fatorial 2x3, sendo dois regimes hídricos, controle (100% da capacidade de campo) e déficit hídrico (20% da capacidade de campo) e três doses da solução de biorreguladores (0, 0,5 e 1,0 L ha-1). A parcela experimental foi constituída de vasos plásticos contendo 12,0 kg de solo com uma planta por vaso das cultivares RB867515 e SP81-3250, para cada tratamento utilizou-se dez repetições. Realizou-se o tratamento das plantas com a solução comercial de biorreguladores Stimulate® nos toletes no momento do plantio e aos 64 dias após o plantio (DAP) via aplicação foliar. O déficit hídrico foi iniciado aos 55 DAP e durante este período foram realizadas avaliações biométricas e fisiológicas nas plantas. Aos 110 DAP realizou-se a avalição de biomassa. O déficit hídrico reduziu o conteúdo relativo de água das plantas, bem como todos os parâmetros fisiológicos, assimilação máxima de CO2 (Amax), condutância estomática (Gs), velocidade máxima de carboxilação das enzimas Rubisco e PEPcase (Vcmax e Vpmax) e ainda, reduziu o crescimento das plantas e a produção de biomassa. No entanto, as plantas que foram tratadas com Stimulate® tiveram menor redução em todos os parâmetros fisiológicos, biométricos e menor redução na produção de biomassa quando comparadas as plantas que não receberam o tratamento com a solução de biorreguladores. Os biorreguladores estimularam principalmente o crescimento do sistema radicular, que promoveu maior absorção de água pelas plantas e, consequentemente, melhor desempenho fisiológico sob déficit hídrico. O Stimulate® atenuou os efeitos do déficit hídrico nos processos fisiológicos, promovendo menor redução em Amax, Vcmax e Vpmax e também menor dano fotoquímico. Essa condição foi responsável pelo maior crescimento (altura e área foliar) aumentando a produção de biomassa total das plantas (raiz, folhas e colmo).

Thesis (M.Sc. (Horticulture)) -- University of Limpopo, 2017 / Refer to document / National Research Foundation of South Africa, and Agricultural Research Council-Universities Collaboration Centreꞌ for scholarship and research

Small stock farming and production accounted for approximately 8.4% of total animal product based agricultural output in the 2011 / 2012 season in South Africa. Large scale commercial farming aside, small stock farming also takes on an important role in poorer and developing rural areas of South Africa, where small stock are kept for a combination of economic and non-economic reasons including financial investment or security, food and resource production, as well as religious or traditional reasons. Blowflies are Dipterids with complex life cycles and complete metamorphoses, causing damage to hides and frequent death in their ovine hosts, as a result of cutaneous myiasis caused by the larval stages. All economically important blowfly species causing veterinary myiasis belong to the superfamily Oestroidea, which contains the three major families Oestridae, Calliphoridae and Sarcophidae. The two most significant blowfly genera in South Africa, Lucillia and Chrysomya, both belong to the family Calliphoridae. Chemical means of preventing and treating blowfly strike by topical application remains the most widely used method and appears to be indispensable at this stage. New molecules or formulations effective against blowfly strike are constantly being sought and form part of an active field of research. Bayer currently manufactures and markets Drastic Deadline Extreme ®, a pour-on formulation containing flumethrin and fluazuron for the control of blue ticks (Rhipicephalus decoloratus) in cattle; its possible action against blowflies in sheep was investigated in an in-vitro model, subsequent to a pilot pharmacokinetic study evaluating the kinetics of fluazuron when applied topically to sheep in this particular combination. The first objective of the project was to determine whether fluazuron has any effect at all on the development of blowfly larvae. An active ingredient from the same family of compounds, namely triflumeron, has been successfully used for several years to control blowfly strike in sheep in South Africa (Zapp ® Pour on - Bayer), but it was uncertain whether or not fluazuron would be effective. Raw fluazuron was applied to six pieces of beef according to a dose calculation based on the registered dose of the test product in cattle, while another six pieces were treated with saline in a similar fashion (n=6). Each piece of beef was placed in its own container along with six late instar larvae and placed in the incubator at 35°C for a further nine days. In this instance, the treated group demonstrated significant development defects with regard to pupation (uneclosed pupae) when analysed using the Mann-Whitney non-parametric t-test (p = 0.002). / Dissertation (MSc)--University of Pretoria, 2016. / Paraclinical Sciences / MSc / Unrestricted

No description available.

The primary objective of this research was to identify practices by which specialty cut flower growers can extend the vase life of cut delphinium, sunflower, and dahlia. Experiments investigated the effects of nitrogen fertilization rate on delphinium 'Guardian Mix' and the effects of deficit irrigation on delphinium 'Guardian Blue.' 'Guardian Mix' plants produced marketable cut stems at nitrogen rates as low as 50 mg/L. Deficit irrigation did not change vase life, stomatal conductance, or transpiration rates of delphinium 'Guardian Blue.' Studies tested the effects of foliar calcium applications or benzyladenine application on sunflower 'Moulin Rouge' and 'Procut Lemon.' Calcium did not change the vase life, stomatal conductance, or transpiration rates of either sunflower cultivar. Benzyladenine applied as a preharvest spray or a postharvest dip did not alter vase life of sunflower 'Moulin Rouge' or 'Procut Lemon.' Transpiration rate and conductance rates of sunflowers significantly decreased in the first three days after harvest. In both sunflower experiments, vase life of 'Moulin Rouge' was shorter than vase life of 'Procut Lemon.' Benzyladenine was also applied to dahlia 'Park Princess' and 'Karma Yin Yang' cut flowers. Benzyladenine did not change dahlia vase life. Dahlia 'Park Princess,' 'Bride to Be,' 'Cherish,' and 'Lollipop' cut flowers were not sensitive to exogenous ethylene. Further experiments tested the effect of flower stage at harvest, vase water temperature, or preharvest fungicide application on dahlia 'Park Princess' and 'Karma Yin Yang' cut flowers. Vase life of 'Park Princess' flowers was extended when flowers were harvested before fully open, but 'Park Princess' flowers harvested at budbreak failed to open completely after harvest. 'Karma Yin Yang' cut flower vase life did not differ when flowers were harvested at different stages. Placing cut dahlias in hot vase water had varied effects, but did not extend vase life of either cultivar. Fungicide applications extended vase life of 'Park Princess' flowers. However, the use of fungicide is not necessary to prevent postharvest fungal infection in cut dahlias. The results of all experiments indicate that optimal handling practices vary between cut flower taxa and that factors determining cut flower vase life are complex. / Master of Science

The objective of this work was to determine if summer dormancy of boxwood could be removed either through nutritional or hormonal means. Buxus sempervirens L. "Suffruticosa", B. sempervirens "Vardar Valley", and B sinica var. insularis (Nakai) "Justin Brouwers" were used for these studies. In the nutrition study, experiments were conducted to examine the effects of various levels of Osmocote 15-9-12 and liquid 10-4-6 on growth of boxwood. Optimal shoot dry weight was achieved at applications of 12 to 16 g Osmocote and 100 – 150 ppm N liquid fertilizer. Leachate EC corresponding to optimal shoot dry weight ranged from 0.5 to 0.7 dS/m for Osmocote and from 0.7 to 1.5 dS/m for liquid fertilizer. While the fertilizer requirements for boxwood optimal dry weight accumulation were determined, additional flushes of growth subsequent to the initial spring flush did not occur for "Vardar Valley" and English boxwood. In the phytohormone study, experiments were conducted that examined the effects of pruning, Promalin (GA4+7 and BA), and defoliation on the growth of three boxwood species. While Promalin applied alone or in conjunction with pruning shows promise of increasing new shoot growth, its response was not consistent from experiment to experiment. In fact, when it was applied in conjunction with defoliation, it dramatically decreased number of new shoots and actually resulted in some shoot mortality. Pruning was also erratic in its promotion of new shoots. Defoliation increased new shoot number dramatically and shows the most promise in overcoming summer dormancy. / Master of Science

Plants of Euphorbia pulchenima Wind. 'Gutbier V-14 Glory Annette Hegg Dark Red', and 'Annette Hegg Brilliant Diamond' were treated with 37 iw a.i. of XE-1019 applied in 102, 204, or 408 ml-m⁻² foliar sprays. Half of the plants received overhead irrigation and the remaining received soil-surface irrigations. No spray carrier volume effect or irrigation effect was observed for final plant height, bract canopy diameter, or for days from start of short days to bloom. The results obtained do not support the hypothesis that spray carrier volume or irrigation method affect the efficacy of XE-1019 on poinsettias.