The purpose of this study was to determine the uptake and distribution of nutrients during the growth of the Cayenne cultivar of Ananas comosus (L) Merr under field conditions in the Eastern Cape. The study was also done to help explain the apparent drop in the nutrient levels in the basal section of the "D"- leaf of the pineapple plant during the winter months and to determine the best part or parts of the plant to sample in order to measure the nutrient status of the pineapple plant at any stage of its growth. The investigation was conducted by selecting a plot within a production land on two farms in the pineapple growing region of the Eastern Cape. Plants were sampled from each plot at regular intervals from planting of the pineapple tops until the harvesting of the fruit of the first plant crop. Plant growth was measured and the nutrient concentrations in each section of the plant were determined. The total amounts of nutrients for each plant part were calculated and the nutrient uptake was compared and plotted on distribution diagrams.

Orientador: Roberto Lyra Villas Bôas / Coorientador: Aniello Cutolo Filho / Banca: Camila Paula Rossetto Pescatori Jacon / Banca: Natália de Brito Lima Lanna / Resumo: Com o desenvolvimento de novos materiais genéticos para atender o mercado, empresas privadas, públicas e outras organizações lançam no mercado anualmente genéticas novas de cultivares de alface, com novas resistências a doenças, novas adaptações climáticas, ciclos de crescimento diferentes e exigências nutricionais diferentes. Sendo assim, é necessário o desenvolvimento de pesquisas sobre nutrição mineral desses novos materiais genéticos, fornecendo ferramentas para o produtor poder fazer um programa de adubação mais eficiente. O objetivo do projeto foi determinar a curva de acúmulo de nutrientes de dois materiais genéticos de alface crespa, uma de ciclo precoce (Valentina) e uma de ciclo tardio (Isadora), em condições de campo. O projeto foi desenvolvido em parceria com a empresa Sakata Seed Sudamerica Ltda que forneceu o material genético. O delineamento experimental utilizado foi de blocos ao acaso com 7 tratamentos e 4 repetições. Os tratamentos consistiram de 7 épocas de avaliação, considerando os dias de coletas como tratamentos (0; 7; 14; 21; 28; 35; 42). As plantas amostradas periodicamente a cada 7 dias foram analisadas quanto aos parâmetros biométricos e ao teor de macro e micronutrientes durante 42 dias. Com base nesses teores e na massa seca, foi calculada a quantidade de nutrientes acumulado pelas plantas de alface, e foram geradas as curvas de acúmulo de nutrientes de cada cultivar. A cultivar Valentina apresentou maior demanda de nutrientes em relação a cultiva... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: With the development of new genetic materials to serve the market, private, public and other organizations are lauching new genetic lettuce cultivars annually, with new disease resistance, new climate adaptations, different growth cycles and different nutritional requirements. Therefore, it is necessary to develop research on mineral nutrition of these new genetic materials, providing tools for the farmer to make a more efficient fertilizer program. The objective of the project was to determine the nutrient accumulation curve of two curly lettuce genetic materials, one early cycle (Valentina) and one late cycle (Isadora) in field conditions. The project was developed in partnership with the Sakata Seed Sudamerica Ltda Company, which provide the genetic material. The experimental design was randomized blocks with 7 treatments and 4 replications. The treatments consisted of 7 evaluation times, considering the collection days as treatments (0; 7; 14; 21; 28; 35; 42). Plants sampled periodically every 7 days, were analyzed for biometric parameters and macro and micronutrient content for 42 days. Based on these contents and dry mass, the amount of nutrients accumulated by lettuce plants was calculated, and the nutrient accumulation curves of each cultivar werw generated. The cultivar Valentina presented higher nutrient demand than Isadora cultivar, potassium was the most accumulated nutrient in lettuce plants. The decreasing order of nutrient accumulation was K>N>Ca>P>Mg>S>Fe>Zn>B>Mn>Cu. / Mestre

The morphology, distribution, and habitat of dwarf and normal forms of Fucus distichus in Nehalem Bay were examined. The dwarf form lacked the holdfast and sexual structures of the normal form and was more highly branched. Examples of the dwarf form were found growing as outgrowths of fragmented normal forms indicating that both forms are the same species. The normal form occurred attached to rocks near the mouth of the bay in waters of oceanic salinity. The dwarf form occurred as a free-living form in the salt marshes and in waters of lower salinity. These observations suggested that the occurrence of the dwarf form is related to salinity. Nutrient uptake studies with nitrate and carbon demonstrated that both forms have similar responses to changes in salinity. The dwarf form however, was better adaptated to the lower salinities than the normal form. Both forms showed a drop in carbon uptake and a slight rise in nitrate uptake as salinity was decreased, but the dwarf form maintained near maximal carbon uptake rates to a much lower salinity. It was shown that carbon uptake is sensitive to sodium and potassium ions, and nitrate uptake is sensitive to potassium ions. Reducing the sodium ion concentration by changing the medium composition decreased the carbon uptake rate. This rate was reduced further by the addition of potassium ion. The addition of sodium and potassium specific ionophores to the medium also depressed the uptake rate of carbon. Nitrate uptake was relatively unaffected by decreased sodium concentrations, but was drastically reduced by elevated potassium levels. The potassium specific ionophore valinomycin also produced a significant drop in the nitrate uptake rate. These data suggested that chemical potentials for sodium and potassium drive the uptake of carbon and that potassium is involved in the uptake of nitrate in F. distichus.

No description available.

Thesis (MTech (Agriculture)--Cape Peninsula University of Technology, 2018. / Choumollier (narrow-stem kale) (Brassica oleracea, L.) has been progressively used in recent years as a supplementary forage harvest in many countries with a temperate climate. Boron (B) and calcium (Ca) are the two most important elements for supporting plant structure and function of plasma membranes. Boron nutrition is vital for obtaining high quality yields in vegetables. The main objective of this study was to evaluate the extent to which boric acid concentration can affect growth parameters (plant height, leaf numbers, chlorophyll levels, and leaf size) of Brassica olereacea var. acephala at different stages of growth and development. Treatment comprised of four concentrations of boron (0.3 mg/kg, 0.4 mg/kg, 0.5 mg/kg and 0.6 mg/kg). Yield and physiological growth responses were measured during the course of the study to ascertain effectiveness and influence of boron treatments on the test crops. Leaves of B. oleracea were harvested at weekly intervals (W1, W2, W3, W4 and W5) after each treatment regimen for approximate basic mineral analysis and composition. Soil pH did not vary much among the various orchard blocks tested, regardless of soil depth. Exchangeable cations Na+ and K+ levels did not vary significantly, but Ca2+ and Mg2+ levels fluctuated considerably among orchards analyzed. The Control Orchard exhibited a higher P content than the other orchards. Ca, Mg, Cu and B levels did not vary significantly among the orchards, but Na, Fe and Zn levels were markedly raised in the Orchard treated with 0.3 mg/kg boron) relative to the Control Orchard. Chlorophyll fluorescence was significantly dependent on the treatment dose of boron as compared to control. Chlorophyll fluorescence also increased significantly with the growth period, i.e., the duration following the initial treatment at all doses of boron. Boron at all did not significantly affect leaf count, leaf length and plant height. The work may add to the body of knowledge on the influence of boron on the physiological performance, mineral contents and proximate composition of leaves of the species. Furthermore, the findings may have important applications in achieving high quality yields in vegetable crops.

Thesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2018. / Pelargoniums have been studied extensively for their medicinal properties. P. reniforme and P. sidoides in particular are proven to possess antimicrobial, antifungal and antibiotic abilities due to their high antioxidant potential from compounds isolated from their tuberous roots. These plants have now been added to the medicine trade market and this is now causing concern for conservationists and they are generally harvested from the wild populations. This study evaluated the effect of water stress alone and in conjunction with arbuscular mycorrhiza on two species of Pelargoniums grown in a soilless medium. The experiment consisted of five different watering regimes which were applied to one hundred plants of each species without inoculation with arbuscular mycorrhiza and to one hundred plants of each species in conjunction with inoculation with AM. All the plants in the experiment were fed with a half-strength, standard Hoagland nutrient solution at varying rates viz. once daily to pot capacity, every three days to pot capacity, every six days to pot capacity, every twelve days to pot capacity and every twenty-four days to pot capacity. The objectives of the study were to measure the nutrient uptake, SPAD-502 levels (chlorophyll production) and metabolite (phenolics) formation of both species, grown under various rates of irrigation and water stress, as well with or without the addition of arbuscular mycorrhiza at planting out. Each treatment consisted of 10 replicates. SPAD-502 levels were measured weekly using a hand held SPAD-502 meter. Determination of nutrient uptake of macronutrients N, K, P, Ca, Mg and Na and micronutrients Cu, Zn, Mn, Al and B were measured from dry plant material at the end of the experiment by Bemlab, 16 Van Der Berg Crescent, Gants Centre, Strand. Plant growth in terms of wet and dry shoot and root weight were measured after harvest. Determination of concentrations of secondary metabolites (phenolic compounds) were assayed and measured spectrophotometrically at the end of the experiment. The highest significant reading of wet shoot weight for P. reniforme was taken in treatments 1 and 2 with and without mycorrhiza i.e. WF1, WF1M, WF2 and WF2M, with the highest mean found in WF1 with no mycorrhiza. This indicates that under high irrigation AM plays no part in plant growth, possibly due to leaching. More research is necessary in this regard. With regard to wet root weight, this was found to be not significant in any of the treatments, other than the longest roots being found in WF4. Measurements for dry root weight showed that WF1,2,3 and 5 were the most significant at P≤ 0.001 significance, with the highest weight found at treatment being WF3 and WF3M. The highest mean of shoot length of the plants was measured in treatment WF2 at moderate watering, but no statistical difference was found with water application and mycorrhiza addition. Nutrient uptake was increased in P. sidoides in all the different watering levels in the experiment except in the uptake of Mg. AM inoculation showed an increase in the uptake of Ca, while absorption of N occurred at higher water availability. K uptake was enhanced by the addition of AM in high water availability and K utilisation decreased as water stress increased. Medium to low watering resulted in higher leaf content in P. sidoides while the interaction between water availability and AM inoculation increased chlorophyll production towards the end of the experiment.

Zhang Siyi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 97-109). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.iii / List of Tables --- p.vii / List of Figures --- p.viii / List of Abbreviations --- p.x / Chapter Chapter 1: --- General Introduction --- p.1 / Chapter Chapter 2: --- Literature Review --- p.3 / Chapter 2.1 --- Phosphorus and higher plants --- p.3 / Chapter 2.1.1 --- Phosphorus is a macronutrient in higher plants --- p.3 / Chapter 2.1.2 --- The forms of phosphorus in plant cells --- p.3 / Chapter 2.1.3 --- Phosphorus compartments and pools in plant cells --- p.6 / Chapter 2.2 --- The acquisition of phosphorus in higher plants --- p.8 / Chapter 2.2.1 --- The forms of phosphorus absorbed by higher plants --- p.8 / Chapter 2.2.2 --- Soil phosphorus bioavailability --- p.9 / Chapter 2.2.3 --- Uptake and transportation of phosphorus --- p.10 / Chapter 2.3 --- Adaptive responses of higher plants to phosphorus deficiency --- p.11 / Chapter 2.3.1 --- Phosphorus homeostasis --- p.12 / Chapter 2.3.2 --- Enhancement of phosphorus uptake --- p.14 / Chapter 2.3.3 --- Phosphorus scavenging and recycling --- p.16 / Chapter 2.4 --- Regulation of gene expression under phosphorus starvation --- p.18 / Chapter 2.5 --- Acid phosphatase and purple acid phosphatase in plants --- p.22 / Chapter 2.5.1 --- Acid phosphatases --- p.22 / Chapter 2.5.2 --- Purple acid phosphatase (PAP) --- p.26 / Chapter Chapter 3: --- Hypothesis --- p.31 / Chapter Chapter 4: --- Materials and Methods --- p.33 / Chapter 4.1 --- Materials --- p.33 / Chapter 4.1.1 --- Chemicals --- p.33 / Chapter 4.1.2 --- Plant materials --- p.33 / Chapter 4.1.3 --- Plasmid vectors and bacterial strains --- p.33 / Chapter 4.1.4 --- DNA sequencing --- p.34 / Chapter 4.1.5 --- Softwares: --- p.34 / Chapter 4.2 --- Methods: --- p.35 / Chapter 4.2.1 --- Survey of PAP occurrence in higher plants --- p.35 / Chapter 4.2.2 --- Determination of multi-gene family and gene copy number of PAPin tomato genome --- p.40 / Chapter 4.2.3 --- Effect of environmental Pi on the morphology of tomato and APase induction --- p.43 / Chapter 4.2.4 --- PAP expression in tomato seedlings growing at different Pi concentrations --- p.46 / Chapter 4.2.5 --- Genomic library construction and PAP promoter isolation --- p.48 / Chapter 4.2.6 --- PAP promoter activity assay by transient expression of reporter gene..… --- p.52 / Chapter Chapter 5: --- Results --- p.56 / Chapter 5.1 --- Identification of PAP gene in higher plants --- p.56 / Chapter 5.1.1 --- Design of primers and total RNA extraction --- p.56 / Chapter 5.1.2 --- RT-PCR --- p.57 / Chapter 5.1.3 --- Further investigation of PAP homologous sequences in monocotyledons --- p.60 / Chapter 5.2 --- Determination of multi-gene family and gene copy number of tomato PAP gene (TPAP 1) --- p.62 / Chapter 5.2.1 --- Determination of TPAP 1 copy number --- p.62 / Chapter 5.2.2 --- Determination of tomato PAP multi-gene family --- p.63 / Chapter 5.3 --- Effect of environmental phosphorus on the morphology of tomato seedling and APase induction --- p.66 / Chapter 5.3.1 --- Morphological changes of tomato seedlings under phosphorus starvation --- p.66 / Chapter 5.3.2 --- Acid phosphatase assays --- p.72 / Chapter 5.4 --- The phosphorus-regulated expression of tomato PAP --- Northern blot analysis --- p.74 / Chapter 5.5 --- Genomic library construction and PAP promoter isolation --- p.76 / Chapter 5.6 --- PAP promoter sequence --- p.79 / Chapter 5.7 --- Promoter activity assay through transient expression of reporter gene --- p.84 / Chapter 5.7.1 --- Effect of untranslation region of PAP gene --- p.84 / Chapter 5.7.2 --- Assay of PAP promoter activities regulated by phosphorus --- p.85 / Chapter Chapter 6: --- Discussion --- p.88 / Chapter 6.1 --- The wide occurrence and high conservation of plant PAP --- p.88 / Chapter 6.2 --- Tomato as a model plant and the organization of PAP gene in genome --- p.89 / Chapter 6.3 --- Morphological changes of tomato under phosphorus starvation and the induction of APase --- p.90 / Chapter 6.4 --- Regulation of PAP in tomato --- p.92 / Chapter 6.5 --- Isolation of PAP promoter --- p.92 / Chapter 6.6 --- Assay of PAP promoter activity --- p.93 / Chapter 6.7 --- Future perspectives --- p.94 / Chapter Chapter 7: --- Conclusion --- p.95 / References --- p.97

Orientador: Magali Leonel / Coorientador: Adalton Mazetti Fernandes / Banca: Thaís Paes Rodrigues dos Santos / Banca: Fábio Rafael Echer / Resumo: A batata-doce é uma cultura que possui alta capacidade de adaptabilidade às diferentes condições climáticas, de solos e resistência às pragas, por isso tem sido cultivada em várias regiões do mundo. Contudo, no seu cultivo ainda há déficit tecnológico, devido à falta de informações e conhecimentos adequados, principalmente, sobre a nutrição mineral das plantas, o que pode resultar em baixas produtividades e qualidade das raízes. O fósforo (P) é um nutriente essencial às plantas e tem atuação na respiração, produção e processos de transformação de energia pela planta, contribuindo para o desenvolvimento radicular. Desta forma, objetivou-se avaliar o efeito da adubação fosfatada sobre a produtividade e qualidade de raízes tuberosas de batata. Foram conduzidos quatro ensaios, ambos com delineamento em blocos casualizados, com esquema fatorial 2 x 5 x 2, com quatro repetições. Os tratamentos consistiram em duas cultivares (Uruguaiana e Canadense); cinco doses de P2O5 (0, 50, 100, 200 e 400 kg ha-1) e duas épocas de cultivo (primeira época: outubro a abril e segunda época: março a outubro). A cultivar Canadense é mais produtiva do que a Uruguaiana, independentemente da época cultivada. Para ambas as cultivares, a época de cultivo entre os meses de outubro e abril proporciona maior produtividade do que a época entre os meses de março a outubro. A produtividade de raízes tuberosas da cultivar Canadense aumenta cerca de 6 toneladas ha-1 com o incremento das doses de fósforo, atingind... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Sweet potato is a crop that has high adaptability to different climatic conditions, soil and pest resistance, so it has been cultivated in various regions of the world. However, in its cultivation there is still a technological deficit, due to the lack of adequate information and knowledge, especially about the mineral nutrition of the plants, which may result in low yields and root quality. Phosphorus (P) is an essential nutrient for plants and acts on respiration, production and energy transformation processes by the plant, contributing to root development. Thus, the objective of this study was to evaluate the effect of phosphate fertilization on potato tuber yield and quality. Four trials were conducted, both with a randomized block design, with a 2 x 5 x 2 factorial scheme, with four replications. The treatments consisted of two cultivars (Uruguaiana and Canadense); five doses of P2O5 (0, 50, 100, 200 and 400 kg ha-1) and two growing seasons (first season: October to April and second season: March to October). The Canadense cultivar is more productive than the Uruguaiana cultivar, regardless of the growing season. For both cultivars, the growing season between October and April provides higher productivity than the season between March and October. The yield of tuberous roots of the Canadense cultivar increases about 6 tons ha-1 with increasing phosphorus doses, reaching a production of 28 tons ha-1, but not the same with Uruguaiana. In low phosphorus soil, nutrient doses between 100 and 150 kg ha-1 of P2O5 are sufficient to promote plant growth and increase yield. Regarding the physicochemical characteristics, the cultivar Uruguaiana has better quality of tuberous roots than Canadense. The second season provided better quality of tuberous roots, regardless of the cultivars. Phosphorus doses interfere with the physical chemical properties of tuberous roots. / Mestre

Orientador: Carlos Alexandre Costa Crusciol / Banca: João Domingos Rodrigues / Banca: Adriano Stephan Nascente / Banca: Orivaldo Arf / Banca: André Fróes de Borja Reis / Resumo: A aplicação da citocinina thidiazuron (TDZ) é uma técnica que promove aumentos na produtividade de arroz (Oryza sativa L.), no entanto, é necessário entender o funcionamento dessa substância em plantas de arroz. Objetivou-se com esse trabalho verificar a influência do TDZ nos aspectos fisiológicos, morfológicos, nutricionais e produtivos de um cultivar de arroz de terras altas. Foi realizado experimento com delineamento em blocos casualizados, aplicando doses de thidiazuron (0, 0,8, 1,6 e 2,4 g ha-1) no perfilhamento do cultivar Ana 8001, favorecido com irrigação por aspersão, durante duas safras (2015/2016 e 2016/2017). Foi avaliado o teor foliar das citocininas 6-benzilaminopurina (BAP) e trans-zeatina ribosídeo (TZR), absorção de N, P, K, Ca, Mg, S, Fe, Cu, Zn e Mn, crescimento da planta, componentes da produção e produtividade de grãos. Realizou-se também experimento em casa de vegetação com o objetivo de verificar a influência de citocininas na altura, componentes da produção, produtividade de grãos e expressão genica de cultivares mutantes de arroz, alterados na rota de sinalização celular desse hormônio. A aplicação de citocinina aumentou os teores foliares de 6-benzilaminopurina e trans-zeatina ribosídeo na primeira safra. O aumento no número de espiguetas por panícula e fertilidade das espiguetas, em função das doses de TDZ, resultaram em incrementos na produtividade na ordem de 24% e 13% na safra 2015/2016 e 2016/2017, respectivamente. Em 2016/2017, os teores de K n... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Application of the cytokinin thidiazuron (TDZ) is a technique which promotes increases in grain yield of rice (Oryza sativa L.), however, it is necessary to understand the action of this substance in rice plants. The objective of this work was to verify the influence of TDZ on the physiological, morphological, nutritional and productive aspects of an upland rice cultivar. A randomized block design experiment was carried out, applying doses of thidiazuron (0, 0.8, 1.6 and 2.4 g ha-1) on tillering stage of the cultivar ANa 8001, favored by sprinkler irrigation, during two crop seasons (2015/2016 and 2016/2017). It was evaluated the leaf content of cytokines 6-benzylaminopurine (BAP) and trans-zeatin riboside (TZR), the uptake of N, P, K, Ca, Mg, S, Fe, Cu, Zn and Mn, plant growing and grain yield. An experiment was also carried out to verify the influence of cytokinins on morphological aspects and genetic expression of mutant rice cultivars, altered in the cellular pathway signaling of this hormone. The application of cytokinin increased leaf contents of 6-benzylaminopurine and trans-zeatin riboside in the first crop season. The increase in the number of spikilets per panicle and spikelet fertility as a function of TDZ doses resulted in increases of 24% and 13% in 2015/2016 and 2016/2017, respectively. In 2016/2017, the leaf K contents increased by 2.0, 6.8, 3.1 and 0.9 g kg-1 with the application of TDZ doses on leaf differentiation, flowering, milky grain and harvest point. respectively. Panicle K content increased 1.91 g kg-1 at harvest point. Despite the climatic differences between the two-crop season, it was possible to observe that cytokinin increases the dry matter accumulation in the leaves and stalk of the plant, being after translocated to the reproductive structures, resulting in increases of grain yield. The OsPHP, OsRR type B and OsCKX rice mutant cultivars showed increases ... / Doutor

Orientador: Carlos Alexandre Costa Crusciol / Coorientador: James Mabry McCray / Banca: Rafael Otto / Banca: Raffaella Rossetto / Banca: Ciro Antonio Rosolem / Banca: Henrique Coutinho Junqueira Franco / Resumo: Objetivou-se avaliar o efeito do fornecimento de concentrações de Mg2+e K+, e da aplicação foliar de Mg2+ no desenvolvimento da raiz e parte aérea, bem como possíveis alterações no estado nutricional e na partição de carboidratos em plantas de cana-de-açúcar. Para tanto, três estudos foram conduzidos: i) avaliação do efeito de concentrações de Mg2+ (controle e deficiente) no desenvolvimento de plantas de cana-de-açúcar; ii) alterações metabólicas e nutricionais na cana-de-açúcar decorrentes do desequilíbrio de Mg2+ causado pelo alto nível de K+; iii) eficiência da aplicação foliar de Mg2+ em plantas de cana-de-açúcar cultivadas em nutrição variada de K+ e Mg2+. Os experimentos foram conduzidos em casa de vegetação e as plantas cultivadas em solução nutritiva. Foram avaliados: o teor de clorofila nas folhas, parâmetros morfológicos das raízes (comprimento e diâmetro radicular), produção de matéria seca das partes da planta, composição nutricional e partição de amido, sacarose e açúcares redutores nas diferentes partes da planta. No geral, o adequado fornecimento de Mg2+ levou a maior produção de matéria seca, concentração de sacarose nos colmos e relação raiz/parte aérea. Clorofila a, b e carotenoides foram menores em plantas deficientes em Mg2+. Ademais, foi observado maior concentração de amido e açúcares solúveis nas folhas e menor concentração de sacarose nos colmos destas plantas. Além disso, plantas deficientes em Mg2+ tiveram menor comprimento radicular e maior diâmetro, do que as quais apresentaram maior concentração de K+ na raiz e maior translocação deste cátion para a parte aérea. O aumento da concentração de K+ na solução nutritiva reduziu a concentração de Mg2+ nas raízes, folhas novas, folhas velhas e colmos da cana-de-açúcar, mesmo nas plantas controle de Mg2+. Independente da nutrição com Mg2+, no maior nível de K+, todos os parâmetros ... / Abstract: The aim of this study was to evaluate the effect of Mg2+ and K+ concentrations, and Mg2+ foliar application on the root and shoot growth, as well as to check the alterations on the nutritional status and carbohydrates partitioning in sugarcane plants. For this purpose, three studies were conducted: i) evaluation of the effect of Mg2+ concentrations (adequate and deficient) on the sugarcane plants development; ii) metabolic and nutritional alterations in sugarcane due to Mg2+ imbalance caused by K+ high level; iii) efficiency of the Mg2+ foliar application in sugarcane plants grown under varied levels of K+ and Mg2+. The experiments were estabilished in greenhouse and the plants grown in nutrition solution. The evalutions were: leaf chlorophyll content, root morphological parameters (length and root diameter), dry matter production of plant parts, nutritional composition and starch, sucrose and reducing sugars partitioning in the different plant parts. In general, the adequate supply of Mg2+ resulted in higher dry matter production, sucrose concentration in the stalks and root/shoot ratio. Chlorophyll a, b and carotenoids were lower in Mg2+ deficient plants. Moreover, higher concentration of starch and soluble sugars were observed in the leaves and lower starch concentration in the stalks of these plants. Besides, Mg-deficient plants had shorter root length and larger diameter, which presented higher K+ concentrations in the root and higher translocation of this cation to the ... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor