Sediment cores obtained during the year 2006 (April, June, September), originated from inflow and dam sites in hypertrophic reservoir were incubated and analyzed in the laboratory under in situ conditions. The aim of this study was to find out the release rates of phosphorus and iron and to define the changes in the concentrations of dissolved compounds in pore water in the first 6 cm in the sediment. Gel minipeepers were used to measure the vertical profiles of dissolved analyts in pore water. This method was found suitable for investigation of P, Fe and basic ions concentrations. Differences between inflow and dam site were found

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Made available in DSpace on 2016-04-28T14:58:59Z (GMT). No. of bitstreams: 1 2009 - Madelon Rodrigues Sa Braz.pdf: 319807 bytes, checksum: 61632a4a4503a071f6f23eaf16cb38e1 (MD5) Previous issue date: 2009-03-05 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The objective of this work was to compare different procedures of the accelerated aging and controlled deterioration tests to evaluate sunflowers achenes vigour, correlate the results of tests conducted in the laboratory with the emergence of sunflower seedlings in the field, evaluate the influence of sunflower achenes vigour on the seedlings establishment and plant performance, evaluate the effect of achenes vigour and sowing density on the sunflower plants growth, evaluate the effect of achenes vigour and sowing density on the nutrients of accumulation and the oil of yield in sunflower plants. For this were installed six experiments. The results showed that the accelerated aging test and controlled deterioration were efficient to classification the sunflowers achenes lots. Under adverse conditions, the achene vigour evaluated by accelerated aging, controlled deterioration and electrical condutivity presented a higher correlation with sunflower plant emergence in field. Sunflower achene vigour improved the development of plants beyond 60 DAS and this effect may persist until the final production, at initial population ausence. Plants originated from smaller achenes vigour showed the lower total dry matter and leaf area index to 80 and 100 DAS, as well as lower culture growth rate in the period from 60 to 100 DAS. The plants conducted under the lower density had higher total dry matter and leaf area index at 40 and 60 DAS, as well as higher culture growth rate and relative growth rate in the period from 20 to 40 DAS. To the 60 days, at flowering high accumulation of dry mater, N, P K and Ca in stem, leaves and total at density of 45,000 seeds.ha-1. The sunflower achenes oil yield and dry mater and nutrients harvest index not affected by the achenes vigour and sowing density to / Os objetivos do trabalho foram de analisar a efici?ncia dos testes de envelhecimento acelerado e deteriora??o controlada na avalia??o do vigor de lotes de aqu?nios de girassol; correlacionar os resultados dos testes conduzidos no laborat?rio com a emerg?ncia das pl?ntulas de girassol em campo; avaliar a influ?ncia do vigor de aqu?nios de girassol no estabelecimento das pl?ntulas e no desempenho das plantas; verificar a influ?ncia do vigor dos aqu?nios e da densidade de semeadura no crescimento de plantas de girassol; avaliar o efeito do vigor dos aqu?nios e da densidade de semeadura no ac?mulo de nutrientes e no rendimento de ?leo em plantas de girassol. Para isto foram instalados seis experimentos. Os resultados permitiram concluir que os testes de envelhecimento acelerado e de deteriora??o controlada foram eficientes para classificar os lotes de aqu?nios de girassol. Em condi??es adversas, a emerg?ncia das pl?ntulas de girassol em campo apresentou maior correla??o com os testes de envelhecimento acelerado, de deteriora??o controlada e de condutividade el?trica. A utiliza??o de aqu?nios vigorosos de girassol foi favor?vel ao desenvolvimento das plantas ap?s 60 DAS e esse efeito persistiu at? a produ??o, na aus?ncia de diferen?a na popula??o inicial. A utiliza??o de aqu?nios de menor vigor produziu plantas com menor massa de mat?ria seca total e ?ndice de ?rea foliar aos 80 e 100 DAS, o que proporciona menor taxa de crescimento da cultura no per?odo de 60 a 100 DAS. Sob menor densidade, as plantas produzem maior massa de mat?ria seca total e ?ndice de ?rea foliar aos 40 e 60 DAS, o que proporciona maior taxa de crescimento da cultura e taxa de crescimento relativo no per?odo de 20 a 40 DAS. Aos 60 DAS, entre o florescimento e o enchimento, ocorreu maior ac?mulo de massa de mat?ria seca e de N, P, K e Ca no caule, nas folhas e total nas plantas de girassol produzidas sob a menor densidade de 45.000 sementes.ha-1. N?o houve efeito do vigor dos aqu?nios e da densidade de semeadura no rendimento de ?leo dos aqu?nios de girassol e nos ?ndices de colheita de massa de mat?ria seca e nutrientes.