O presente trabalho tem por objeto o estudo dos conhecimentos obtidos de forma fortuita, através da realização legal de um meio de obtenção de prova autorizado judicialmente, que não se reportam ao crime cuja investigação legitimou a medida restritiva. A fim de viabilizar essa abordagem foi necessário rever alguns conceitos relacionados à noção de prova no processo penal, que se colocam como pontos de partida para o enfrentamento do assunto. Na sequência, os conhecimentos fortuitos são inseridos no tema da obtenção da prova criminal, ligada à proteção da intimidade e da privacidade, tendo como foco principal a interceptação das comunicações telefônicas e a busca domiciliar. Para tanto, toma-se em consideração o princípio da especialidade da prova, que justifica que a limitação a direitos fundamentais esteja restrita e vinculada à apuração do crime que ensejou tal intervenção, motivo pelo qual o direito ao sigilo das comunicações e o direito à inviolabilidade da intimidade e do domicílio são analisados sob a perspectiva do panorama constitucional e legal brasileiro. A questão passa necessariamente pela análise do tema no Direito Comparado e pelo levantamento das diversas manifestações encontradas na doutrina e na jurisprudência nacional sobre a problemática, sobretudo em razão do silêncio legislativo quanto à solução jurídica da questão no ordenamento pátrio. Assim, após afastar as teses que defendem a negação absoluta dos conhecimentos fortuitos ou sua valoração sem restrições, conclui pela necessidade de se delimitar as fronteiras entre os conhecimentos imputados à própria investigação e aqueles que, inversamente, se levam em conta de conhecimentos fortuitos, socorrendo-se para tanto de um critério objetivo que concretize essa distinção. Isto porque, dela dependerá o tratamento a ser conferido aos conhecimentos obtidos em investigação de crime diverso, no que se refere à sua admissibilidade no processo e sua valoração pelo julgador como elemento de prova, apto à demonstração do delito casualmente descoberto, ou sua eventual utilização como mera notícia de crime formadora de indício. Por fim, são enfrentadas questões específicas suscitadas durante o desenvolvimento do estudo, e que colocam à prova o critério adotado. / The present paper has as its aim the study of knowledge obtained from fortuitous way through a legal means of obtaining evidence legally authorized, that does not relate to the crime which investigation legitimized the restraint measure. In order to make this approach it was necessary to review some concepts related to the notion of evidence in criminal proceedings, which arise as starting points for the confrontation of the subject. In the continuation, the fortuitous knowledge is inserted into the topic of obtaining criminal evidence, linked to the protection of privacy and intimacy, having as its main focus the interception of telephone communications and home search. To do so, it is taken into account the principle of specialty of evidence, which justifies that limiting the fundamental rights is restricted and tied to the investigation of the crime that resulted in such an intervention, which is why the right to confidentiality of communications and the right to inviolability of domicile and intimacy are analyzed from the perspective of constitutional and legal Brazilian panorama. The question goes necessarily through by examining the topic in Comparative Law and the survey of various manifestations found in doctrine and national case law on the issue, especially in view of the legislative silence as to the legal solution of the matter in land use. So, after removing the arguments defending the absolute denial of the fortuitous knowledge or its valuation without restrictions, it is concluded by the need to delimit the boundaries between imputed knowledge to the research itself and those that, conversely, are taken into account of fortuitous knowledge, helping to as much of an objective criterion that achieves this distinction. This is because from it will depend the treatment to be given to information obtained in the investigation of crime, as regards its admissibility in the process and its valuation by the Court as evidence to the demonstration of the offense or its possible use discovered fortuitously as mere forming crime news clue. Finally, specific issues are faced raised during the development of the study, and that put to the test the adopted criterion.

Pasture-based systems are important milk suppliers to dairy industry and thereby will play relevant role to support the growing demand for food. However, this additional milk supply must be obtained through higher yields resulting from intensification of existing farming systems through strategies environmentally friendly and economically profitable towards sustainable intensification. The central hypothesis of this study was that simple grazing management strategies can improve the efficiency while reduce the key environmental issues of tropical pasture-based dairy systems. Two experiments were carried out on a rainfed and non-irrigated elephant grass (Pennisetum purpureum Schum. cv. Cameroon) pasture in Piracicaba, SP, Brazil. The objective of the first experiment was to investigate the influence of two pre-grazing targets (95% and maximum canopy light interception during pasture regrowth; LI95% and LIMAX, respectively) on sward structure and herbage nutritive value, dry matter intake (DMI), milk yield, stocking rate, enteric methane (CH4) emissions by Holstein × Jersey dairy cows, and nitrous oxide fluxes from the soil. Results indicated that pre-grazing canopy height was greater for LIMAX (≈135 cm) than LI95% (≈100 cm) and can be used as a reliable field guide for monitoring sward structure. Grazing management based on the LI95% target improved herbage nutritive value and grazing efficiency, allowing greater DMI, milk yield and stocking rate by dairy cows. Daily enteric CH4 emission was not affected; however, cows grazing elephant grass at LI95% were more efficient and emitted 21% less CH4/kg of milk yield and 18% less CH4/kg of DMI. The 51% increase in milk yield per hectare overcame the 29% increase in enteric CH4 emissions per hectare for the LI95% target. Nitrous oxide fluxes were not affected by pre-grazing targets. Overall, strategic grazing management is an environmentally friendly practice that improves the use efficiency of allocated resources through optimization of processes involving plant, ruminant and their interface, and enhances milk production efficiency of tropical pasture-based systems. Once the ideal pre-grazing target was established during he first experiment (LI95%), the second step consisted of a refinement of the first phase. The second objective was to describe and measure the influence of two timings of new paddock allocation to cows (AM and PM) on herbage chemical composition and DMI, milk yield, milk compostion, and enteric CH4 emissions of Holstein × Jersey dairy cows. Results supported the general understanding of diurnal variation in herbage chemical composition towards greater concentrations of dry matter and non-fibrous carbohydrates, and lower concentration of fiber components in the afternoon herbage. However, the higher nutritive value of the afternoon herbage did not result in increasead DMI and milk yield, or decreased intensity of CH4 emission by dairy cows. Our findings also indicate that new paddock allocation in the afternoon can be a simple and useful grazing strategy that results in greater N partitioning to protein yield, and lower excretion of urea N in milk. The association of LI95% pre-grazing target and PM allocation could bring economic, productive and environmental benefits towards sustainable intensification of tropical pasture-based systems. / Sistemas baseados no uso de pastagens são importantes fornecedores de leite para a indústria de latícinios e, dessa forma, terão papel relevante para suportar a crescente demanda por alimentos. No entanto, essa oferta adicional de leite deve ser obtida através de maiores produtividades resultantes da intensificação de sistemas de produção já existentes por meio de estratégias ambientalmente seguras e economicamente rentáveis em direção à intensificação sustentável. A hipótese central deste estudo foi que estratégias simples de manejo do pastejo podem melhorar a eficiência e, ao mesmo tempo, reduzir os principais impactos ambientais dos sistemas de produção animal em pastagens tropicais. Foram realizados dois experimentos em pastagem de capim-elefante (Pennisetum purpureum Schum. Cv. Cameroon) não-irrigada em Piracicaba, SP, Brasil. O objetivo do primeiro experimento foi avaliar a influência de duas metas pré-pastejo (95% e máxima interceptação de luz pelo dossel durante a rebrotação; IL95% e ILMáx, respectivamente) sobre a estrutura do pasto e valor nutritivo da forragem, consumo de matéria seca (CMS), produção de leite, taxa de lotação, emissões de metano entérico (CH4) de vacas HPB × Jersey, e o fluxo de óxido nitroso dos solos. Os resultados indicaram que a altura pré-pastejo foi maior para ILMáx (≈135 cm) do que IL95% (≈100 cm) e pode ser usada como um guia de campo confiável para monitorar a estrutura do pasto. O manejo do pastejo com base nos critérios de IL95% melhorou o valor nutritivo da forragem e a eficiência de pastejo, permitindo maior CMS, produção de leite e taxa de lotação. A emissão diária de CH4 entérico não foi afetada; no entanto, as vacas que pastejaram o capim-elefante manejado por IL95% foram mais eficientes e emitiram 21% menos CH4/kg de leite e 18% menos CH4/kg de MS consumida. O aumento de 51% na produção de leite por hectare superou o aumento de 29% nas emissões de CH4 entérico por hectare para a meta IL95%. Os fluxos de óxido nitroso não foram afetados pelas metas pré-pastejo. De maneira geral, o manejo do pastejo com base na meta IL95% é uma prática ambientalmente segura que melhora a eficiência de uso dos recursos alocados por meio da otimização de processos envolvendo plantas, ruminantes e sua interface, e aumenta a eficiência da produção de leite em sistemas baseados em pastagens tropicais. Uma vez que a meta pré-pastejo ideal foi estabelecida durante o primeiro experimento (IL95%), a segunda etapa consistiu-se em um refinamento da primeira. O segundo objetivo foi descrever e medir a influência de dois horários de alocação de novos piquetes aos animais (AM e PM) sobre a composição química da forragem, CMS, produção e composição do leite, e emissões de CH4 entérico de vacas HPB × Jersey. Os resultados confirmaram a compreensão geral da variação diurna na composição química da forragem em direção a maiores concentrações de matéria seca e de carboidratos não-fibrosos, e menor concentração de componentes da fibra na forragem amostrada pela à tarde. No entanto, o maior valor nutritivo da forragem da tarde não aumentou o CMS e a produção de leite, nem diminuiu a intensidade de emissão de CH4 das vacas leiteiras. Os resultados também indicaram que a alocação à tarde pode ser uma estratégia de manejo simples e útil que resulta em maior partição de N para produção de proteína, e menor excreção de N ureico no leite. A associação da meta pré-pastejo IL95% e a alocação do rebanho para um novo piquete à tarde poderia trazer benefícios econômicos, produtivos e ambientais para a intensificação sustentável de sistemas baseados em pastagens tropicais.

<p>Dissecting the soybean grain yield (GY) to approach it as a sum of its associated processes seems a viable approach to explore this trait considering its complex multigenic nature. Monteith (1972, 1977) first defined potential yield as the result of three physiological efficiencies: light interception (Ei), radiation use efficiency (RUE) and harvest index (HI). Though this rationality is not recent, few works assessing these three efficiencies as strategies to improve crops have been carried out. This thesis approaches yield from the perspective of Ei, RUE, and HI to better understand yield as the result of genetic and physiological processes. This study reveals the phenotypic variation, heritability, genetic architecture, and genetic relationships for Ei, RUE, and HI and their relationships with GY and other physiological and phenological variables. Similarly, genomic prediction is presented as a viable strategy to partially overcome the tedious phenotyping of these traits. A large panel of 383 soybean recombinant inbred lines (RIL) with significant yield variation but shrinkage maturity was evaluated in three field environments. Ground measurements of dry matter, photosynthesis (A), transpiration (E), water use efficiency (WUE), stomatal conductance (gs), leaf area index (LAI) and phenology (R1, R5, R8) were measured. Likewise, RGB imagery from an unmanned aircraft system (UAS) were collected with high frequency (~12 days) to estimate the canopy dynamic through the canopy coverage (CC). Light interception was modeled through a logistic curve using CC as a proxy and later compared with the seasonal cumulative solar radiation collected from weather stations to calculate Ei. The total above ground biomass collected during the growing season and its respective cumulative light intercepted were used to derive RUE through linear models fitting, while apparent HI was calculated through the ratio seeds dry matter vs total above-ground dry matter. Additive-genetic correlations, genome wide association (GWA) and whole genome regressions (WGR) were performed to determine the relationship between traits, their association with genomic regions, and the feasibility of predicting these efficiencies through genomic information. Our results revealed moderate to high phenotypic variation for Ei, RUE, and HI. Additive-genetic correlation showed a strong relationship of GY with HI and moderate with RUE and Ei when the whole data set was considered, but negligible contribution of HI on GY when just the top 100 yielding RILs were analyzed. High genetic correlation to grain yield (GY) was also observed for A (0.87) and E (0.67), suggesting increase in GY can be achieved through the improvement of A or E. The GWA analyses showed that Ei is associated with three SNPs; two of them located on chromosome 7 and one on chromosome 11 with no previous quantitative trait loci (QTLs) reported for these regions. RUE is associated with four SNPs on chromosomes 1, 7, 11, and 18. Some of these QTLs are novel, while others are previously documented for plant architecture and chlorophyll content. Two SNPs positioned on chromosome 13 and 15 with previous QTLs reported for plant height and seed set, weight and abortion were associated with HI. WGR showed high predictive ability for Ei, RUE, and HI with maximum correlation ranging between 0.75 to 0.80. Both directed and undirected multivariate explanatory models indicate that HI has a strong relationship with A, average growth rate of canopy coverage for the first 40 days after planting (AGR40), seed-filling (SFL), and reproductive length (RL). According to the path analysis, increase in one standard unit of HI promotes changes in 0.5 standard units of GY, while changes in the same standard unit of RUE, and Ei produce increases on GY of 0.20 and 0.19 standard units. This study presents novel genetic knowledge for Ei, RUE, HI and GY along with a set of tools that may contribute to the development of new cultivars with enhanced light interception, light conversion and optimized dry matter partitioning in soybean. This work not only complements the physiological knowledge already available with the genetic control of traits directly associated with yield, but also represents a pioneer attempt to integrate traditional physiological traits into the breeding process in the context of physiological breeding<br></p>

Des systèmes de culture innovants doivent être proposés pour répondre aux nouveaux objectifs de l'agriculture qui devront allier productivité, respect de l'environnement et rentabilité économique. Les systèmes de culture en semis direct sous couvert végétal (SCV) avec cultures associées permettraient d'atteindre ces objectifs. Si ces systèmes ont en effet montré des intérêts en climat tropical, ils sont presque inexistants en climat tempéré.<br />Cette thèse se propose d'accroître les connaissances scientifiques sur ces systèmes particuliers pour faciliter leur conception et leur évaluation en climat tempéré. Le travail repose sur un dispositif expérimental mis en place à Grignon (Yvelines, France) en 2002 pour trois campagnes culturales. Du blé tendre d'hiver (Triticum aestivum L.) est semé (i) dans un sol labouré, (ii) directement dans les résidus de la culture précédente et, (iii) directement dans six plantes de couverture différentes. En combinant sur ce dispositif une double approche, systémique et analytique, les objectifs de la thèse sont de comprendre, selon l'espèce de couverture, (i) l'impact des différents SCV avec cultures associées sur le rendement de la culture de vente en mettant en évidence les phases de sensibilité aux stress de cette culture, (ii) les relations de compétition et/ou de facilitation pour l'azote et la lumière entre les espèces associées et, (iii) l'évolution, à court terme, de la structure du sol et de ses propriétés hydriques.<br />Ce travail montre que la présence d'une plante de couverture peut réduire, parfois fortement, le rendement de la culture de vente, différemment selon l'espèce de couverture, sa conduite technique et les conditions climatiques ; les phases d'élaboration du rendement qui sont perturbées dans ces situations culturales dépendent aussi de ces trois facteurs. De plus, l'étude met en évidence que la compétition pour le rayonnement lumineux entre les espèces associées est le processus le plus défavorable au rendement du blé.<br />A court terme, il n'apparaît pas de différences marquées entre la structure d'un sol non travaillé sans plante de couverture et celle d'un sol non travaillé avec une plante de couverture. Toutefois, l'étude révèle que les propriétés hydriques peuvent être modifiées selon l'absence ou la présence d'une plante de couverture sur un sol non travaillé sans démontrer de variations importantes de ces propriétés selon l'espèce de couverture.<br />La thèse fournit des informations scientifiques et techniques sur le fonctionnement, en climat tempéré, de peuplements associant sur un sol non travaillé, une culture de vente à différentes plantes de couverture. Elle montre la faisabilité mais aussi les risques des SCV avec cultures associées ; elle permet d'identifier des axes de recherche pour compléter les connaissances et fournir des références pour réduire ces risques.

Dans les systèmes agroforestiers simples à deux strates, la distribution de la lumière sous les couronnes des arbres est un facteur clé pour le développement de la culture associée. Cette distribution évolue en fonction des saisons et de la dynamique de croissance de la strate arborée. La lumière disponible pour la culture dépend de la quantité de lumière interceptée par les couronnes des arbres et par conséquent de l'architecture des espèces utilisées. L'objectif de cette thèse est de déterminer le rôle de l'architecture de deux espèces, Acacia mangium Willd. et Tectona grandis L., dans (i) les modalités de l'interception de la lumière par les couronnes et par les feuilles et (ii) les variations intra- et interspécifiques de la distribution du rayonnement sous les couronnes de ces arbres selon leur âge. A partir de l'analyse dynamique des processus de croissance et de ramification de ces deux espèces, un échantillonnage des organes foliaires a permis de déterminer leur répartition, leur géométrie et leurs caractéristiques morphologique, anatomique, optique et biochimique dans les couronnes. Par la simulation de la croissance, de ces deux espèces, paramétrée via des lois mathématiques de croissance et de ramification, des reconstructions 3D d'arbres ont été réalisées en vue de simuler le bilan radiatif de sous-parcelles agroforestières. Les résultats montrent de fortes variations inter- et intraspécifiques de la distribution des organes foliaires et leurs caractéristiques au sein de la couronne et de la distribution du rayonnement sous les couronnes. Les stratégies adoptées par ces deux espèces pour optimiser l'interception lumineuse sont discutées

Au delà de la diversité architecturale bien décrite entre variétés chez le pommier, une variabilité fonctionnelle est suspectée, encore très mal connue, qui pourrait se répercuter sur leur productivité et sur leurs capacités d'adaptation. Par ailleurs, il est postulé que la variabilité fonctionnelle des cultivars à une échelle intégrée dépend à la fois de l'organisation architecturale de leur système aérien et d'une variabilité du fonctionnement de leur feuillage.<br />La comparaison qui a été réalisée entre génotypes a porté sur 4 cultivars de pommier : Fuji et Braeburn d'une part, Ariane et X3305 d'autre part, dont les arbres étaient respectivement âgés de sept ans et de deux ans au début de l'étude. Les arbres ont été cultivés dans un verger expérimental irrigué et soumis à des pratiques culturales standard.<br />L'étude de la variabilité architecturale entre arbres a mis en évidence des différences de dynamique de mise en place de la surface foliaire entre individus jeunes et plus âgés. Des différences de composition raméale entre arbres de même âge ont également été révélées, ayant pour conséquence des différences d'efficience d'interception lumineuse entre cultivars qui ont été quantifiées par le paramètre STAR (Silhouette to Total leaf Area Ratio). Une méthode de description de la structure des arbres en 3D, reposant sur une approche mixte de digitalisation et de reconstruction du feuillage, a été validée.<br />L'étude fonctionnelle à l'échelle foliaire a mis en évidence une diversité de la régulation stomatique des 4 génotypes en réponse aux facteurs abiotiques (modèle de Jarvis), alors que les paramètres photosynthétiques (modèle biochimique de Farquhar) s'avéraient peu variables.<br />Les caractéristiques architecturales et fonctionnelles de chaque cultivars ont été prises en compte dans la paramétrisation et l'utilisation du modèle structure-fonction RATP, afin d'évaluer l'impact de leur couplage sur les capacités d'interception lumineuse, de transpiration et d'assimilation de carbone à l'échelle intégrée de la branche fruitière. Une analyse de sensibilité du modèle pour le cultivar Braeburn a permis de mettre en évidence le rôle prépondérant de l'architecture des arbres dans la variabilité de fonctionnement à cette échelle.<br />Les perspectives ouvertes par cette approche écophysiologique chez le pommier au moyen d'un modèle structure fonction sont discutées.

Comme chez de nombreux protéagineux, l'architecture déterminée a semblé une voie prometteuse pour réduire le développement végétatif et améliorer le rendement et la stabilité du rendement du lupin blanc d'hiver (Lupinus albus L.). Une étude à la fois génétique et physiologique de ce type architecturale et de ses conséquences sur le développement et la mise en place du rendement a donc été entreprise. L'hérédité du caractère d'architecture déterminée est monogénique récessive, ce qui permet une utilisation simple en sélection. Le développement végétatif est réduit car tous les bourgeons passent à l'état floral précocément dans le cycle. Les ramifications portent chacune moins de feuilles que chez les indéterminés, et le nombre de niveaux végétatifs est réduit. La distribution des feuilles sur les ramifications suit un profil caractéristique en forme de cloche. La structure des ramifications a pu être modélisée. Il existe une grande variabilité génétique pour l'architecture, bien que la relation positive entre tardiveté de floraison et développement végétatif soit forte. L'interception de la lumière par le couvert en fonction du temps est similaire chez les déterminés et les indéterminés. Cependant, les déterminés atteignent une interception maximale moins importante en raison de leur développement végétatif restreint. La proportion de lumière qui parvient jusqu'aux feuilles de la tige principale est accrue. Le rendement des génotypes déterminés semble compétitif avec celui des génotypes indéterminés. La production de matière sèche est plus faible mais l'indice de récolte est supérieur. La date de maturité est sensiblement avancée, surtout sous des climats frais et humides, et la stabilité du rendement est plus grande. Ces caractéristiques sont liées à la réduction du développement végétatif, et à une compétition entre développement végétatif et développement reproducteur plus faible que celle observée chez les indéterminés. Le rendement est produit essentiellement sur la tige principale et le premier niveau de ramifications, et ces sites sont moins sujets à des aléas climatiques que les niveaux supérieurs. La variabilité génétique pour les composantes du rendement est large. On met en évidence des relations entre certains caractères d'architecture et les potentialités de rendement. Un développement végétatif trop restreint aussi bien qu'un développement excessif nuisent au rendement. Les caractères de développement des ramifications (nombre de feuilles et nombre de niveaux végétatifs) sont des critères de sélection pertinents chez les lupins déterminés.

Rainfall interception is a primary control over the moisture input to a forested ecosystem through the partitioning of precipitation into throughfall, stemflow, and an evaporated component (i.e. the interception loss). Rainfall interception is a spatially and temporally varying process at multiple scales, but heterogeneity in interception processes are poorly understood and poorly described in the literature. We need to know how net precipitation varies in ecosystems because natural systems are driven by non-linear ecohydrological processes where mean values cannot capture localized effects or the cumulative consequences associated with an extremely heterogeneous input. In this thesis, we present two studies that investigate the heterogeneity of interception loss and throughfall in a forested catchment in the western Cascades range of Oregon. In one study, we examined the spatio-temporal patterns among point measurements of throughfall depth and isotopic composition to determine the cause of isotopic differences between throughfall and rainfall. Our results indicated that the residual moisture retained on the canopy from previous events plays a major role in determining the isotopic composition of the next event's throughfall. Differences between the isotopic composition of throughfall samples could indicate further partitioning of throughfall into various flow-paths from the canopy. The second project examined the question of how vegetation variability and terrain complexity drive interception loss heterogeneity at the whole-catchment scale. We applied a simple interception model to a watershed gridded at a 50 m resolution to investigate the relative importance of topographic and vegetative controls over the spatial variability of interception loss. We found that storm characteristics are crucial regarding the impact of spatial heterogeneities in vegetation and evaporation rates. In the Pacific Northwest climate, interception loss is not highly variable for the majority of the year because the annual precipitation is dominated by large storms with low interception losses. However, the net precipitation input to a watershed becomes extremely heterogeneous in the summer due to high interception loss variability. Summer interception loss could be an important control over the spatial variability of the availability of moisture, coinciding with when vegetation is most water-limited. / Graduation date: 2013

Emissions of radionuclides to the atmosphere can lead to wet deposition on plants in theevent of rainfall. An increased level of radioactivity in the plants may occur due tointerception and retention of the radionuclides. If the content of the plants is above thethreshold limit value, entire yields may have to be destroyed. In order to preventcontamination or decrease the content countermeasures can be taken. The impact of thebiomass, leaf area index (LAI) and growth stage of the plant on the interception andretention is important to know in order to decide which countermeasures to use.Weather may also be an important factor. In this work the interception and retention of 134Cs and 85Sr by spring wheat, ley andspring oil-seed rape was studied. The impact of the biomass, LAI and growth stage ofthe plant and precipitation after deposition was also studied. The work was conducted asa field study with plots of the size 1 x 1 m. The plants were wet deposited with 134Cs and 85Sr by using a rain simulator. A total activity of 40 kBq/m2 for both radionuclideswas deposited on each plot. Depositions were performed during four different growthstages and the plants were sampled approximately four hours, one and five days afterdeposition. Activities of the dried plant samples were measured with a High PurityGermanium (HPGe) detector. Finally the interception fraction and the retention factorwere calculated. The study showed that the interception fraction was highest for the third growth stagefor both wheat and oil-seed rape; dough ripeness for wheat and ripening for oil-seedrape. Ley, which was harvested after two depositions, had the highest interceptionfraction at the second growth stage, flowering. Oil-seed rape and ley seemed to have aslightly higher interception fraction for 85Sr at all growth stages. There was a positiverelationship for the biomass and interception fraction, for the LAI and interceptionfraction the relationship wasn’t significant. The retention showed a weak trend ofdecreasing with time, with the decrease being largest during the first day after theinterception. However, the standard deviation was large and consequently the values uncertain. / Utsläpp av radionuklider till atmosfären kan genom regn leda till att de våtdeponeras påväxter. Radionukliderna kan då fångas upp av växterna och hållas kvar vilket kanresultera i förhöjda halter av radioaktivitet hos växterna. Om detta leder till attgränsvärden överskrids kan kassering av växter som används vid livsmedelsproduktionvara nödvändig. Motåtgärder kan vidtas för att undvika kontaminering eller minskahalterna. För att veta vilka motåtgärder som ska användas är det viktigt att veta hurväxtens biomassa, bladyteindex (LAI), utvecklingsstadium samt väderförhållandenpåverkar uppfångningen och kvarhållningen. I detta arbete undersöktes uppfångningen och kvarhållningen av 134Cs och 85Sr hosvårvete, vall och vårraps. Inverkan av växtens biomassa, LAI och utvecklingsstadiumsamt nederbörd efter deponering undersöktes också. Arbetet genomfördes som ettfältförsök med försöksrutor med storleken 1 x 1 m. Växterna våtdeponerades med 134Csoch 85Sr med hjälp av en regnsimulator. En total aktivitet på 40 kBq/m2 för bådaradionukliderna deponerades per försöksruta. Deponeringar skedde under fyra olikaväxtutvecklingsstadier och växtprover togs ungefär fyra timmar efter deponering samtett och fem dygn senare. Aktiviteten hos de torkade växtproverna mättes med en HighPurity Germanium (HPGe) detektor. Därefter beräknades uppfångningsfraktioner ochkvarhållningsfaktorer. Försöket visade att uppfångningsfraktionen var störst vid det tredjeväxtutvecklingsstadiet för både vete och raps; degmognad för vete och fröutveckling förraps. Vallen, som slogs av efter två deponeringar, uppvisade störst uppfångningsfraktionvid andra växtutvecklingsstadiet, blomning. Hos raps och vall verkadeuppfångningsfraktionen för 85Sr vara något högre vid samtliga växtutvecklingsstadier.För biomassan och uppfångningsfraktionen fanns ett positivt samband, för LAI ochuppfångningsfraktionen var sambandet inte signifikant. Kvarhållningen visade en svagtrend att minska med tiden, minskningen var störst under det första dygnet efteruppfångningen. Dock var standardavvikelsen stor och värden därmed osäkra.

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