O planejamento de colheita na cultura da cana-de-açúcar busca otimizar o retorno econômico, baseado no conceito de que a cana tem uma época, durante o ano, onde ocorre máxima concentração de sacarose nos colmos. Realizaram-se neste trabalho estudos enfocando as influências dos fatores edafo-climáticos sobre o rendimento e açúcares totais recuperáveis. Foram testadas as hipóteses de que há interação entre as épocas de plantio e corte, bem como a hipótese de que há interação do tratamento muda inteira e picada com cada época de plantio. Utilizaram-se dados de pesquisa conduzida, no Campo de experimentação da COPERSUCAR – Piracicaba/SP, num solo Latossol Vermelho Eutrófico. O delineamento utilizado foi blocos ao acaso, com parcelas subdivididas em faixas e sub-subparcelas dentro das faixas. Os tratamentos foram épocas de plantio (Novembro, Janeiro, Março, Maio), as faixas foram épocas de corte (Maio, julho, Setembro, Novembro), e os sub-subtratamentos foram mudas picada e inteira. Mediram-se as variáveis: toneladas de colmos (TCH) e toneladas de açúcar por hectare (TAH), e açúcar total recuperável (ATR). A soqueira foi avaliada da mesma forma que o 1º corte, aos (12) meses de idade. Foram instalados três experimentos, cada um com uma variedade, SP 70-1143, NA 56-79 e SP 71-1406. Os experimentos foram instalados e repetidos em três anos-safra, 1983/84, 1984/85 e 1985/86, com colheitas nas safras dos anos de 1985 até 1988, obtendo-se assim, rendimentos de estágios iguais em anos diferentes e estágios diferentes no mesmo ano. Concluiu-se que as épocas de plantio afetaram TCH, ATR e TAH do 1º corte; épocas de plantio interagiram com os tipos de mudas na cana planta; épocas de corte afetaram TCH, ATR e TAH nas canas planta e soqueiras; ATR sempre evoluiu do início para o final da safra, com os picos nos meses de setembro e novembro; plantios tardios atrasam a maturação; os valores de TAH acompanham as curvas de ATR sendo influenciados por TCH. Para a variedade SP 70-1143 no primeiro corte o clima influenciou os resultados de épocas de plantio e de tipos de mudas; os menores valores de TCH foram obtidos nas épocas de plantio Maio com mudas de cana picada e nas demais épocas de plantio não houve diferenças, indicando que se podem plantar mudas de cana inteiras em qualquer época; nos dois cortes estudados, os maiores valores de ATR foram obtidos na colheita de Setembro e os menores valores foram obtidos na época de plantio de Maio indicando que o pico de maturação ocorre no mês de setembro. Para a variedade NA 56-79 os valores de TCH das mudas picadas e inteiras não mostraram diferenças indicando que se pode plantar cana inteira; os maiores valores de ATR e TAH foram obtidos a partir das colheitas de Julho. Para a variedade SP 71-1406, no primeiro corte, houve superioridade para mudas picadas sendo o melhor manejo, os menores valores de TCH foram obtidos no plantio de Maio e o maior valor de ATR foi obtido na colheita de Novembro; nos dois cortes os valores de TAH e de ATR indicaram que a colheita deve ser feita partir de setembro. / Harvest planning in sugarcane attempts to optimize the crop's economic return based on the concept that sugarcane presents, along the cropping season, a period during which the maximum concentration of sucrose occurs in the stalks. This work consisted of studies that focused on the influences of edaphic-climatic factors on yield and total recoverable sugars. The hypothesis was tested that an interaction exists between the planting and harvesting seasons, as well as the hypothesis that an interaction exists between the whole-stalk and the bud seedling treatments with each planting season. Data from a research conducted at COPERSUCAR’s Experimental Field – Piracicaba/SP, in a Red Eutrophic Latosol, were used. A random blocks design with strip split-plots was used, where sub-subplots were allocated within strips. Treatments were planting seasons (November, January, March, May), with harvesting seasons represented by strips (May, July, September, November), while sub-subtreatments consisted of bud and whole-stalk seedlings. The variables measured were: tons of sugarcane stalks (TSS) and tons of sugar per hectare (TSH), and total recoverable sugar (TRS). The ratoon (second cut) was evaluated in the same manner as the 1st cut, when sugarcane was 12 months old. Three experiments were installed, each consisting of one variety: SP 70-1143, NA 56-79, and SP 71-1406. The experiments were installed and replicated in three cropping years: 1983/84, 1984/85, and 1985/86, with harvests in the cropping seasons from 1985 through 1988; therefore, yields for the same stage in different years, and yields for different stages in the same year were obtained. It was concluded that planting seasons affected TSS, TRS, and TSH in the 1st cut; planting seasons interacted with seedling types in one-year-old sugarcane; harvesting seasons affected TSS, TRS, and TSH in one-year-old and ratoon sugarcane; TRS always progressed from the beginning to the end of the cropping season, with peaks in the months of September and November; late plantings delayed maturation; TSH values followed the TRS curves, and were influenced by TSS. In the first cut of variety SP 70-1143, climate influenced the planting season and seedling type results; the smallest TSS values were obtained in the May planting seasons with bud seedlings, while no differences were observed in the other planting seasons, indicating that whole-stalk seedlings can be planted in any season; in both cuts under study, the highest TRS values were obtained for the September harvesting, and the smallest values were obtained for the May planting season, indicating that peak maturity occurs in the month of September. In variety NA 56-79, the TSS values for bud and whole-stalk seedlings did not show differences, indicating that whole-stalk cane can be planted; the highest TRS and TSH values were obtained from harvests made in July. In the first cut of variety SP 71-1406, the best management consisted of bud seedlings, which were superior; the smallest TSS values were obtained for the May planting and the highest TRS value was obtained for the November harvesting; in both cuts, the TSH and TRS values indicated that harvesting should be done beginning in September.

CAPES / Currently there is a need to produce seedlings at low cost and with high quality to be used in the recovery of degraded areas and the use of arbuscular mycorrhizal fungi (AMF) can improve their development in low fertility soils. AMF have several benefits for the plants, because they promote increased survival and establishment of seedlings in the field, as with the symbiosis hyphae improve water use and nutrients. And before this, the present study aimed to evaluate the growth of seedlings Albizia polycephala inoculated with different AMF. First they were produced inoculants through traps vessels with species of native AMF obtained from samplings in the rhizosphere of matrices Albizia polycephala. Later two experiments were conducted, the first being tested five species of AMF from the Collection arbuscular mycorrhizal fungi of Embrapa Agrobiology (COFMEA), mounted in a completely randomized block design with six treatments (control - without inoculation, Scutellospora calospora (T.H. Nicolson & Gerd.) C. Walker & F.E. Sanders, Acaulospora colombiana (Spain & N.C. Schenck) Kaonongbua, J.B. Morton & Bever, Claroideoglomus etunicatum (W.N. Becker & Gerd.) C. Walker & A. Sch??ler, Dentiscutata heterogama (T.H. Nicolson & Gerd.) Sieverd., F.A. Souza & Oehl e Gigaspora margarita W.N. Becker & I.R. Hall) and nine repetitions. In the second experiment inoculants native AMF were tested (native inoculant) and the best species of AMF in the first experiment (Embrapa inoculant). The experimental design was randomized blocks with eight repetitions, in a factorial 3 x 4, that is, three treatments (a witness - no inoculation and two inoculants - native inoculum and mixture of three species from COFMEA) and four doses of P (0, 35, 140 and 350 mg/dm?), applied in the form of superphosphate. The seed Albizia polycephala germinated in trays with sand and vermiculite (2: 1with based on volume) and when the seedlings had a pair of leaves were transplanted with the inoculant in plastic containers of 700 ml with PVC cartridge 380 cm? coupled your background. During the experiments were conducted biweekly measurements of height and diameter and after collection, the root colonization rate assessments, spore density, dry matter of shoot, root dry matter, reason root /shoot and leaf phosphorus content . The results obtained through the evaluations showed that the species of Acaulospora colombiana was the most effective in promoting the growth of Albizia polycephala. Furthermore, the inoculant of COFMEA provided better growth in different phosphorus levels than native inoculant. Thus, it can be stated that the tested species has association with AMF efficiently and has high dependence mycorrhizal. / Atualmente existe a necessidade de se produzir mudas a baixo custo e com ?tima qualidade para serem utilizadas na recupera??o de ?reas degradadas e a utiliza??o dos fungos micorr?zicos arbusculares (FMAs) pode melhorar o seu desenvolvimento em solos de baixa fertilidade. Os FMAs apresentam v?rios benef?cios para as plantas, pois promovem uma maior sobreviv?ncia e estabelecimento das mudas no campo, j? que com a simbiose as hifas melhoram o aproveitamento de ?gua e nutrientes. E diante disso o presente trabalho teve como objetivo geral avaliar o crescimento de mudas de Albizia polycephala inoculadas com diferentes FMAs. Primeiramente foram produzidos inoculantes atrav?s de vasos armadilhas com esp?cies de FMAs nativos, obtidos a partir de coletas de solo na rizosfera de matrizes de Albizia polycephala. Posteriormente foram realizados dois experimentos, sendo no primeiro testadas cinco esp?cies de FMAs provenientes da Cole??o de fungos micorr?zicos arbusculares da Embrapa Agrobiologia (COFMEA), em blocos inteiramente casualizados, com seis tratamentos (Testemunha ? sem inocula??o, Scutellospora calospora (T.H. Nicolson & Gerd.) C. Walker & F.E. Sanders, Acaulospora colombiana (Spain & N.C. Schenck) Kaonongbua, J.B. Morton & Bever, Claroideoglomus etunicatum (W.N. Becker & Gerd.) C. Walker & A. Sch??ler, Dentiscutata heterogama (T.H. Nicolson & Gerd.) Sieverd., F.A. Souza & Oehl e Gigaspora margarita W.N. Becker & I.R. Hall) e nove repeti??es. No segundo experimento foram testados os inoculantes de FMAs nativos (inoculante nativo) e as melhores esp?cies de FMAs do primeiro experimento (inoculante Embrapa). O delineamento experimental utilizado foi em blocos casualizados com oito repeti??es, em fatorial 3 x 4, ou seja, tr?s tratamentos (uma testemunha ? sem inocula??o e dois inoculantes ? in?culo nativo e mistura de tr?s esp?cies provenientes da COFMEA) e quatro doses de P (0, 35, 140 e 350 mg/dm?), aplicado na forma de superfosfato simples. As sementes de Albizia polycephala germinaram em bandejas contendo areia e vermiculita (2:1com base em volume) e quando as pl?ntulas tinham um par de folhas foram transplantadas junto com o inoculante em recipientes pl?sticos de 700 ml com tubete de PVC de 380 cm? acoplado em seu fundo. Durante os experimentos foram realizadas medi??es quinzenais de altura e di?metro e ap?s a coleta, as avalia??es de taxa de coloniza??o da raiz, densidade de esporos, mat?ria seca da parte a?rea, mat?ria seca da raiz, raz?o raiz/parte a?rea e teor de f?sforo foliar. Os resultados obtidos atrav?s das avalia??es mostraram que a esp?cie de Acaulospora colombiana foi a mais eficiente em promover o crescimento de Albizia polycephala. Al?m disso, o inoculante da COFMEA proporcionou melhores crescimentos em diferentes doses de f?sforo do que o inoculante nativo. Desta forma, pode-se afirmar que a esp?cie testada apresenta associa??o com FMAs de forma eficiente e tem alta depend?ncia micorr?zica.

Made available in DSpace on 2017-07-10T17:37:17Z (GMT). No. of bitstreams: 1 Karina_Heberle.pdf: 852717 bytes, checksum: 38d66278615e8631603b7471461bf5c7 (MD5) Previous issue date: 2016-07-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Lignin is an indispensable biomolecule for many biological processes of plants. It is one of the most important is to contribute to stem verticality and to ensure the transport of water and minerals. Thus, the search for modulatory ways of lignin biosynthesis is important especially with the application of growth regulators. This research was conducted with Handroanthus impetiginosus seedlings and American patagonula subjected to concentrations of acid jasmonic (0,5 μmol L-1, 1 μmol L-1 e 1,5 μmol L-1). The experiment was conducted as a completely randomized design in the nursery and in a randomized block in the field, with four treatments and five replications. The quantification of lignin was performed by the Van Soest method. In the field, measurements included seedling height, diameter, and number of leaves to evaluate seedling quality. In addition, I calculated the ratio of height to stem diameter, the ratio of above ground dry biomass to weight of the dry roots and Dickson quality index (DQI). Data analysis and graphs from the analysis of variance were performed with Statistics, considering a confidence level of 5%. After the imposition of treatments seedlings of H. impetiginosus externalized the smallest increment in height and the ratio between height and diameter for the three doses of AJ, compared to the control. There was an increase in the Dickson quality index, in lignin concentration in the above ground tissues and root in seedlings that received 1 μmol L-1 and 1,5 μmol L-1. For P. americana seedlings, the doses of 1 μmol L-1 and 1,5 μmol L-1 resulted in increased growth of stem diameter. There was a reduction of the ratio of height to diameter for all tested AJ concentrations. DQI and lignin percentage of the above ground tissues increased as a result of application of 1 μmol L-1 de AJ. In the field, the percentage of seedling survival of H. impetiginosus and P. americana was 100% 90 days after planting. H. impetiginosus seedlings showed increased stem diameter with application of 1,5 μmol L-1. P. americana seedlings resulted in small values for H/D as a result of application of 1 μmol L-1 and 1,5 μmol L-1 of AJ. The results indicated that jasmonic acid may be an effective way of promoting seedling rustification in order to improve the initial seedling performance of H. impetiginosus and P. americana seedlings after planting / A lignina é uma biomolécula indispensável a diversos processos biológicos das plantas, dentre eles o mais importante é conferir rigidez necessária à manutenção da verticalidade do caule e assegurar a existência de vias rápidas de circulação da água e minerais. Nesse sentido, a busca de sistemas moduladores da biossíntese da lignina pode ser alcançada com a aplicação de reguladores de crescimento. Esta pesquisa teve como objetivo avaliar o efeito da pulverização exógena de ácido jasmônico na biossíntese de lignina em mudas de Handroanthus impetiginosus e Patagonula americana, onde foram aplicadas diferentes concentrações do regulador vegetal ácido jasmônico (0,5 μmol L-1, 1 μmol L-1 e 1,5 μmol L-1). O experimento foi composto por delineamento inteiramente casualizado em viveiro e em blocos casualizados a campo, contando com quatro tratamentos e cinco repetições. A quantificação da lignina foi realizada pelo método de Van Soest. A campo também foram realizadas análises morfométricas (altura, diâmetro, número de folhas) para avaliar a qualidade das mudas, além de índices de qualidade, como a relação altura da parte aérea/diâmetro do coleto, a relação do peso de matéria seca da parte aérea/ peso de matéria seca das raízes e o índice de qualidade de Dickson (IQD). A análise dos dados foi realizada com o auxílio do programa estatístico Statistics e os gráficos gerados a partir da análise de variância, considerando significância em nível de 5% de probabilidade do erro. Após a imposição dos tratamentos as mudas de H. impetiginosus externaram menor incremento em altura e relação altura e diâmetro para as três doses de AJ, comparadas à testemunha. Houve aumento no índice de qualidade de Dickson, na concentração de lignina da parte aérea e da raiz, nas doses de 1 μmol L-1 e 1,5 μmol L-1. Para as mudas de P. americana, as doses de 1 μmol L-1 e 1,5 μmol L-1 colaboraram para o aumento do incremento no diâmetro do coleto. Houve redução da relação altura da parte aérea/ diâmetro do coleto para as três concentrações de AJ. Na avaliação do IQD e do teor de lignina da parte aérea, houve aumento com a concentração de 1 μmol L-1 de AJ. No campo, 90 dias após o plantio, o percentual de sobrevivência das mudas de H. impetiginosus e P. americana foi 100%. Para as mudas de H. impetiginosus houve diferenças apenas no incremento do diâmetro do coleto na concentração de 1,5 μmol L-1 de AJ. As mudas de P. americana externaram menores valores para a relação H/D nas concetrações de 1 μmol L-1 e 1,5 μmol L-1. Os resultados indicam que dependendo da concentração utilizada de ácido jasmônico pode ser eficiente em promover a rustificação e melhorar o desempenho inicial a campo de mudas de H. impetiginosus e P. americana

Made available in DSpace on 2017-07-10T17:37:40Z (GMT). No. of bitstreams: 1 Viviane_ Marcela_Celant.pdf: 1184406 bytes, checksum: 25e047278d73b047a52fde1e543ce7d5 (MD5) Previous issue date: 2010-02-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Developed a protocol for the production of seedlings grafted on quince rootstock 'Japanese' (Chaenomeles sinensis) in winter. Thus, the present work had for objective to study the cold storage of cuttings of quince cultivars and treatment with indolbutyric acid, the viability of the budsticks storage of different cultivars of quince by cold storage, and to verify the grafting method to promote better development of the graft and also to study the viability of conservation and cryopreservation of seeds of quince Japones . To achieve this goal, three experiments had been carried through. In the firs experiment, were used hardwood cuttings of quince 'Cheldow' and 'Marmelo Pera'. Some of the cuttings were stored in cold, and other part was placed directly to take root, in the rooting bed in the nursery. The cuttings were treated with different concentrations of indolbutyric acid: 0, 1000, 2000 and 3000 mg L-1, for 10 seconds. After 75 days, we evaluated the percentage of rooted cuttings, callous, sprouting and alive, average number of leaves and shoots, length of shoots and roots, mass dries average of the aerial part and roots. In the second experiment branches of quince Japones (Chaenomeles sinensis), Smyrna , Portugal , Mendoza Inta-37 and Provence (Cydonia oblonga) had been collected in July of 2008. A part of the branches were used for grafting by the methods of budding and cleft grafting in seedlings of nine months of age of the rootstock 'Japanese' and another part was stored in cold chamber at 4 ° C for 30 and60 days. After 60 days of grafting, was measured the percentage of sprouted of the rootstock and the final 120 days of the completion of grafting the length, diameter and average dry weights of the grafts. In the third experiment, a part of the seeds of quince 'Japanese' were sown immediately (32.8% moisture) and the remain had the humidity lowered for 14,14%. Part of the seeds with 14,14% humidity was stratified for 20 days in refrigerator in Petri dishes lined with moistened cotton, another part was stored for 3, 6, 9 and 12 months within plastic tubes in the temperature of 20 ° C 5 o C and -12 o C, and the other part of the seeds were placed in cryotubes and stored in cryogenic storage for 20 days. After storage, all seeds were stratified and sown in the same way and placed in chamber B.O.D. We evaluated the germination percentage at the end of stratification and four assessments spaced seven days. It was concluded that the cuttings of cultivating `Cheldow' if propagate more easily, cold storage increases the percentage of rooting and sprouting, with higher rooting when treated with 2000 mg L-1 IBA; to cultivate although them to present difference, it is recommended that the branches are stored for up to 30 days if using the grafting method of grafting. You can store the seeds of quince for up to 9 months under room temperature (20 C) or for long periods through cryopreservation, allowing the assignment of the production of rootstocks and still supporting the storage of germplasm / Desenvolveu-se um protocolo de produção de mudas de marmeleiro enxertadas no porta-enxerto Japonês (Chaenomeles sinensis) no inverno. Assim, o presente trabalho teve por objetivo estudar o armazenamento a frio de estacas de cultivares de marmeleiro e o tratamento com acido indolbutirico, a viabilidade da manutenção dos ramos porta-borbulha de diferentes cultivares de marmeleiro através do armazenamento a frio, e diagnosticar o método de enxertia a promover melhor desenvolvimento do enxerto e ainda estudar a viabilidade da conservação e crioconservação de sementes do marmeleiro Japonês . Para atingir tal objetivo, foram realizados três experimentos. No primeiro experimento, foram utilizadas estacas lenhosas dos marmeleiros Cheldow e Marmelo Pera . Parte das estacas foram armazenadas em câmara fria, e outra parte foi colocada diretamente para enraizar, em leito de enraizamento, em viveiro. As estacas foram tratadas com diferentes concentrações de acido indolbutirico: 0, 1000, 2000 e 3000 mg L-1, por 10 segundos. Apos 75 dias, avaliou-se a porcentagem de estacas enraizadas, calejadas, brotadas e vivas, numero médio de folhas e brotos, comprimento médio de brotos e raízes, massa seca media da parte aérea e das raízes. No segundo experimento ramos dos marmeleiros Japonês (Chaenomeles sinensis), Smyrna , Portugal , Mendoza Inta-37 e Provence (Cydonia oblonga) foram coletados em julho de 2008. Uma parte dos ramos foram utilizados para a realização da enxertia pelos métodos de borbulhia e garfagem, em mudas de nove meses de idade do porta-enxerto Japonês e outra parte foi armazenada em câmera fria a 4oC por 30 e 60 dias. Passados 60 dias da realização da enxertia, foi mensurada a porcentagem de brotação dos enxertos e ao final de 120 dias da realização das enxertias o comprimento, diâmetro e massa seca media dos enxertos. No terceiro experimento, uma parte das sementes do marmeleiro Japonês foram semeadas imediatamente (32,8% de umidade) e o restante teve a umidade rebaixada para 14,14%. Parte das sementes com umidade de 14,14% foi estratificada por 20 dias em geladeira em placas de Petri forradas com algodão umedecido, outra parte foram armazenadas por 3, 6, 9 e 12 meses dentro de tubos plásticos, sob a temperatura de 20oC, 5oC e -12oC, e a outra parte das sementes foram colocadas em criotubos e armazenadas em crioconservação por 20 dias. Apos o armazenamento, todas as sementes foram estratificadas e semeadas nos mesmos moldes e colocadas em câmara tipo B.O.D. Avaliou-se a porcentagem de germinação ao final da estratificação e por mais quatro avaliações espaçadas de sete dias. Concluiu-se que as estacas do cultivar Cheldow se propagam mais facilmente, o armazenamento a frio aumenta a porcentagem de estacas enraizadas e brotadas, com maior enraizamento quando tratadas com 2000 mg L-1 de AIB; apesar dos cultivares apresentarem diferença, recomenda-se que os ramos sejam armazenados por ate 30 dias, se utilizando a enxertia pelo método de garfagem. E possível armazenar as sementes de marmeleiro por ate 9 meses sob a temperatura ambiente (20oC) ou por longos períodos através da crioconservação, possibilitando o escalonamento da produção dos porta-enxertos e ainda dando suporte ao armazenamento de germoplasma

Substratos alternativos têm sido usados para promover um melhor estabelecimento de plantas em viveiros, de forma a assegurar que plantas sadias sejam transferidas ao campo. No caso do Citrus spp. Esta preocupação é real pela possibilidade do campo poder apresentar um histórico de doenças na área, tal como a Clorose Variegada do Citros causada pela Xylella fastidiosa (X.f.). Este estudo avaliou a adição de vermicomposto a um substrato comercial e o desenvolvimento de plântulas de quatro variedades de citros inoculadas ou não com X.f. em condições de casa-de-vegetação, por um período de 450 dias. Medidas biométricas do crescimento da planta e o uso de indicadores do balanço nutricional usando o programa DRIS - Diagnosis and Recommendation Integrated System foram aplicadas em plantas de 9 meses de idade. As variáveis estudadas foram: substrato vermicomposto (100%, 50%, 0%) , variedade (Baia, Pêra, Natal e Escape) e inoculação (com ou sem X.f.) em um total de 24 tratamentos (variedade x substrato x inoculação), com seis repetições. Quanto ao desenvolvimento das plantas, avaliou-se o diâmetro do caule, a altura da planta, a produção de biomassas das raízes e partes aéreas, a taxa de infecção natural por fungos micorrízicos naturais do solo, a concentração de macro e micronutrientes na parte aérea. Quando se usou vermicomposto (100% or 50%), efeitos positivos foram observados nos parâmetros de desenvolvimento das plantas. Por outro lado, a infecção micorrízica e DRIS foram inversamente correlacionadas indicando estar ocorrendo um desbalanço nutricional neste estádio de desenvolvimento das plantas. Não foi observado um efeito significativo da inoculação com X.f. no desenvolvimento das plantas ou mesmo nos parâmetros biométricos, exceto para os teores foliares de nitrogênio e fósforo, onde nas plantas inoculadas o teor foliar de nitrogênio (1,46%) foi maior em relação às plantas não inoculadas (1,30%) e para fósforo ocorreu o oposto (0,32% e 0,40%, respectivamente). / Alternative substrates have being used for a better establishment of plants at nursery stages, thus ensuring that healthier plants will be transferred to the field. In the case of Citrus, this is a concern especially when there is a past history of diseases at field conditions, such as Citrus Variegated Chlorosis caused by Xylella fastidiosa (X.f.). This study evaluated the addition of vermicompost to a commercial substrate and the performance of seedlings of four citrus varieties inoculated or not with X. f. at greenhouse condition, for a period of 450 days. Biometric measurements of plant growth and nutritional balance indicators using DRIS - Diagnosis and Recommendation Integrated System were performed in 9 month-old plants. Mycorrhizal infection by native vesicular-arbuscular fungi was also evaluated in all plants. The studied variables were: vermicompost substrate (100%, 50%, 0%), variety (Baia, Pêra, Natal and Escape) and inoculation (with or without X.f.), in a total of 24 treatments (variety x substrate x inoculation) with 6 replicates each. Growth development evaluated stem diameter, plant height, shoot and root biomass accumulations, arbuscular mycorrhizal infection, and macro and micronutrient concentration in the shoot. When using vermicompost (100% or 50%), positive effects were observed in the plant growth parameters. On the other hand, mycorrhizal infection and DRIS were inversely correlated to the substrate addition, indicating that nutrient imbalances may be occurring at this plant growth stage. No significant effect of X.f. inoculation was observed on the plant growth and the biometric parameters studied, except for increased foliar nitrogen content - 1,46% for inoculated and 1,30% for uninoculated plants, and decreased foliar phosphorus content - 0,32% for inoculated and 0,40% for uninoculated plants.

No description available.

Aphids are a widespread family of plant pests, whose abilities to suppress shoot and root growth are well documented for many terrestrial plants. Only a few studies have been conducted on conifer aphids of the genus Cinara. Cinara pseudotsugae are known to attack Douglas-fir seedlings, an important crop in the Pacific Northwest. Douglas-fir are most susceptible to aphid damage as seedlings, especially in nurseries where conditions favor aphid outbreaks. A parasitoid wasp (Pauesia sp.) attacks C. pseudotsugae, and may be useful as a biological control agent. Studies of its natural history and host interactions are needed to assess its potential as a bio-control agent. This study examined the effects of an experimental range of aphid densities on the growth of total shoot and root volume and biomass and shoot morphology of Douglas-fir seedlings. Eighteen-week tests explored short term effects of different aphid feeding intensities in both the greenhouse and field. Long term effects were tested by exposing greenhouse seedlings to 16 months of aphid feeding. The ability of the plants to recover was tested by allowing one set of seedlings to grow aphid free for one year, after being exposed to aphid feeding for 18 weeks. The success rate of parasitoids over an 18 week period was compared to aphid density in both greenhouse and field tests. Increasing aphid destiny was significantly related to decreasing root and shoot dry weights in greenhouse tests. Growth suppression increased slightly during the second year of testing, regardless of whether or not aphid feeding continued. The results for root and shoot volumes were highly variable. However, root tissue density was significantly reduced after the second year of testing. Few shoot characteristics showed consistently significant aphid effects among the trials. Stem diameter and height decreased and needle density of new buds increased significantly with aphid feeding in most tests. Root and shoot growth of field plants did not show any significant aphid effects. Percentage of parasitoid success was independent of aphid density except at the lowest aphid densities. There was a block effect on parasitoid success in the field test, that may have been a result of varying environmental conditions. These results indicate that even short term aphid feeding can have long lasting effects on plant growth and structure. The effect on shoot and root growth was small, but there were no signs of recovery. The long term effects of the reduced root tissue density on Douglas-fir is unknown. / Graduation date: 1998

Mutants showing developmental hyper-responsiveness to limited light were screened and designated as seedlings hyper-responsive to light (shl). These mutants showed an etiolated phenotype similar to wild type in the dark, yet had shorter hypocotyls, larger cotyledons, and more advanced development of true leaves than wild type in low light. The SHL genes act (genetically) as light-dependent negative regulators of photomorphogenesis, possibly in a downstream signaling or developmental pathway that is shared by the major photoreceptor genes (CRY1, PHYA, and PHYB) and other photoreceptors (CRY2, PHYC, PHYD, and PHYE). shl1 and shl2 were shown to be partially dependent on HY5 activity for their light-hyperresponsive phenotypes. shl1-1 showed a defect in responding to auxin in its root development in both white and yellow light conditions, and showed a defect in responding to auxin in hypocotyl elongation in yellow light. Compared to wild type, both shl1-1 and shl2-2 showed increased hypocotyl length in response to cytokinin in white light. Gibberellin (GA) partially recovered shl1-1 mutant phenotype in yellow light, whereas showed no effect on hypocotyl elongation of shl2-2 in this light condition. These altered responses of shl1-1 and shl2-2 to multiple phytohormones in different light regimes suggests that cross-talks among light and hormones regulate SHL1 and SHL2. One of the SHL genes, SHL2 was cloned by map-based positional cloning and shown to be allelic to the previously identified locus designated murus3(mur3) and katamari1(kam1). MUR3/KAM1 encodes a XyG galactosyltransferase. Sequence analysis demonstrated that our original EMS generated reference allele shl2-2 is probably not a null mutant, therefore the phenotypes of T-DNA insertion null mutant in SHL2, SALK_074435 were studied in different light conditions. Unlike shl2-2, SALK_074435 had a slightly short hypocotyl phenotype in the dark (though not to the extent of the det/cop/fus mutants). A consideration of the phenotypes and molecular lesions of shl2-2 and mur3 alleles, along with the phenotypes of null alleles kam1 and SALK_74435, suggests that SHL2/MUR3/KAM1 may be involved in hypocotyl elongation in low light through the modification of xyloglucan in the plant cell wall, and may play a role in hypocotyl elongation in the dark through proper organization of the endomembrane.

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniversitet, 2009. / Härtill 5 uppsatser.

No description available.