Com a continuação do aquecimento global, prevê-se o aumento dos períodos de seca, um dos mais importantes fatores abióticos a afetar o crescimento dos eucaliptos no Brasil. Nessa direção, as práticas silviculturais poderiam adaptar-se para favorecer os mecanismos de adaptação das árvores à seca. Assim, na Estação Experimental de Itatinga, foram avaliados os efeitos da adubação potássica sobre os aspectos produtivos e fisiológicos de um povoamento de Eucalyptus grandis, em primeira rotação, submetido à exclusão parcial de chuva durante trinta meses após o plantio. O dispositivo experimental foi um split plot, com três blocos completos e quatro tratamentos: dois regimes hídricos (100% e 63% das chuvas, com exclusão parcial artificial) e duas doses de K (0 e 4,5 kmol ha-1). A meta foi avaliar a influência da nutrição potássica sobre as características e a atividade fotossintética das folhas. A transpiração foi medida por sensores de fluxo de seiva para estimar a eficiência de transpiração do povoamento. O potencial foliar e as trocas gasosas foliares foram monitorados, enquanto os valores de \'delta\'13C do floema foram medidos, para avaliar o estado hídrico e o funcionamento estomático das árvores, em função da disponibilidade de K e de água. Os resultados mostraram que a adição de K atuou sobre vários mecanismos responsáveis pelo aumento do crescimento e da produção de madeira: aumento da área foliar total e individual, da duração de vida foliar, do tamanho e da turgescência celular foliar, da espessura foliar e dos espaços intercelulares no mesófilo foliar, da capacidade fotossintética, da condutância dos estômatos e do mesófilo, da exportação dos fotoassimilados, produzidos nas folhas-fontes, do fluxo de seiva, da eficiência de transpiração na produção de madeira, pelo aumento da repartição de biomassa nesse compartimento. Folhas com sintomas de deficiência de K mostraram concentrações de nutrientes, espaços intercelulares e atividade fotossintética inferiores, e concentrações de açúcares solúveis superiores, na comparação com o tratamento com K, sugerindo uma ligação entre nutrição, anatomia e fisiologia foliar. Durante o déficit hídrico, o E. grandis mostrou um comportamento isohidrodinâmico, associado ao fechamento estomático, ao ajustamento foliar osmótico, à diminuição na elasticidade das paredes celulares, ao aumento na eficiência de uso da água nas folhas, à diminuição da área foliar total e à rápida absorção da água nas camadas profundas do solo. A partir de aproximadamente 22 meses após o plantio, o estado hídrico das árvores diminuiu: (1) nas parcelas com exclusão parcial de chuva, em relação às parcelas sem exclusão parcial de chuva, e (2) nas parcelas com adição de K, em relação às parcelas sem essa adição. Embora a adição de K melhore as relações hídricas nas folhas, o controle dos movimentos estomáticos e as trocas gasosas foliares, ela agravou o estado hídrico das árvores durante períodos de seca intensa, devido ao maior crescimento e à demanda hídrica. Assim, os efeitos benéficos da adição de K sobre a adaptação à seca das árvores poderiam não contrabalançar o aumento do déficit hídrico durante períodos mais intensos de seca. Em relação às previsões futuras de seca, as empresas florestais, provavelmente, terão de adaptar a fertilização para minimizar a demanda de água e os riscos de mortalidade / Global warming is predicted to exacerbate drought, one of the most important abiotic stress factors affecting eucalypts growth in Brazil. Silvilcultural practices might be adapted to enhance drought adaptation mechanisms of trees. This study examined the effects of K addition on productive and physiological aspects of Eucalyptus grandis stands in first rotation submitted to partial through fall exclusion over thirty months after planting. A large-scale through fall exclusion experiment using a split plot design was conducted with three blocks and four treatments: two water regimes (100% and 63% of through fall with partial artificial exclusion) and two K doses (0 and 4.5 kmol ha-1). The influence of K nutrition on characteristics and photosynthetic activity of leaves was assessed Tree transpiration was measured from sap flow probes to estimate water use efficiency. Foliar water potential and gas exchange were monitored, and phloem \'delta\'13C was measured in order to evaluate tree water status and stomatal regulation depending on K and water availabilities. The results showed that K supply influence various mechanisms responsible for tree growth enhancement: increase in total and individual leaf area, leaf lifespan, cell turgor and cell size due to an increase in turgor, leaf thickness and intercellular spaces, photosynthetic capacity, stomata and mesophyll conductances, photoassimilate export from source leaves and transpiration efficiency for wood production through increase of biomass partitioning to this compartment. Leave with K-deficiency symptoms exhibited lower nutrient concentrations and photosynthetic activity, reduced intercellular spaces, and higher soluble sugar contents compared to healthy leaves, which suggested a strong link between nutrition, leaf anatomy and physiology. The adaptive mechanisms of E. grandis trees to cope with water restriction were an isohydrodynamic behavior associated with stomatal closure, osmotic adjustment, a decrease in wall cell elasticity, an increase in foliar water use efficiency, a decrease in total leaf area and a fast water uptake in very deep soil layers. From approximately 22 months after planting onwards, tree water status was lower: (1) in droughted plots compared to the rain-fed plots and, (2) in K-fertilized plots, compared to the K-unfertilized trees. Although K addition enhanced tree water relations, stomatal control and leaf gas exchange, it exacerbated tree water deficit during severe drought as a result of high water demand throughout tree development. Therefore, the beneficial effects of K supply on tree acclimation to drought may not counterbalance the increase in water deficit during severe water restriction periods compared to the K-unfertilized trees. Regarding future drought previsions, forest managers might have to adapt their fertilization regimes to minimize water demand and risks of mortality

Leafy vegetables, lettuce (Lactuca sativa L. cv. Green Oakleaf), pak choi (Brassica sinensis L. cv. Oriental Taisai) and rocket (Eruca sativa L.), were planted in an open field at Lincoln University on January 2005. Plants were harvested at 5 cm cutting height above the growing point with three different harvest start times, early start (ES), mid start (MS) and late start (LS) of harvest respectively. There were three harvests during the growing season with a 4-week interval between harvests. Generally, lettuce produced significantly higher total FW/plant (208 g) than pak choi or rocket (123 and 102 g total FW/plant, respectively). Lettuce also produced significantly higher total FW/plant than pak choi or rocket in each treatment. Lettuce produced significantly more total saleable leaf FW/plant in the ES, MS and LS treatment (137.5, 120.9 and 169.3 g FW/plant), compared with pak choi (52.9, 100 and 92 g FW/plant) or rocket (31.5, 92.2 and 56.4 g FW/plant). Pak choi produced higher total saleable leaf FW/plant than rocket in the ES and LS treatments, but a similar total saleable leaf FW/plant in the MS treatment. The best time to start harvesting was the LS treatment for lettuce, while pak choi and rocket produced better yields in the MS and LS treatments. Results for total DW/plant showed that different harvest start times did not affect the total DW/plant in lettuce. However, pak choi and rocket produced less total DW/plant in the ES treatment compared to the MS or LS treatments. This was due to a faster recovery by lettuce. In addition, lettuce produced significantly higher DW/plant during regrowth at the second and third harvests than pak choi or rocket, even though it was significantly lower at the first harvest. It is likely that after harvesting greater carbohydrate reserves and greater remaining leaf area produced greater regrowth potential in lettuce. These results suggest that lettuce has the most regrowth potential, while rocket has more than pak choi in this reaping and regrowth system. When plants were harvested at the same cutting level, lettuce had the most remaining leaf area of the three species. This remaining leaf area for lettuce could be another reason for faster recovery and more regrowth potential. More reserves and remaining leaf area may also be the reason for more regrowth potential in rocket compared to pak choi. Another important reason for the better performance of lettuce was that temperatures during the growing season were in the range of optimum temperatures (12-21 ºС), except for the regrowth between the second and third harvests in the LS. This relates to higher photosynthetic rates and in turn leads to faster recovery and regrwoth. Lettuce was the most suitable crop in the reaping and regrowth system in this experiment. However, rocket might also be appropriate for this system, particularly if the price is high enough to make it economically viable.

ISBA-A-gs est une option du modèle de surface continentale du CNRM, ISBA, qui simule les échanges de carbone entre la biosphère terrestre et l'atmosphère. Au cours de cette thèse, le modèle est utilisé pour la première fois à l'échelle globale en mode forcé. Plusieurs simulations globales sont réalisées pour évaluer la sensibilité des flux turbulents et du LAI à un doublement de CO2 et au changement climatique prévu pour la fin du XXIe siècle.<br />Une nouvelle option du modèle, nommée ISBA-CC, est aussi développée afin de simuler de manière plus réaliste la respiration de l'écosystème, en distinguant la respiration autotrophe et la respiration hétérotrophe.<br />La validation de la dynamique de la végétation et des flux de carbone échangés, à la fois à l'échelle globale à l'aide de données satellitaires, et à l'échelle locale sur 26 sites de mesure du réseau FLUXNET, montre que le modèle de surface est suffisamment réaliste pour être couplé à un modèle de circulation générale, afin de simuler les interactions entre la surface continentale, l'atmosphère et le cycle du carbone.

Monitoring biophysical variables at a global scale over long time periods is vital to address the climatechange and food security challenges. Leaf Area Index (LAI) is a structure variable giving a measure of the canopysurface for radiation interception and canopy-atmosphere interactions. LAI is an important variable in manyecosystem models and it has been recognized as an Essential Climate Variable. This thesis aims to provide globaland continuous estimates of LAI from satellite observations in near-real time according to user requirements to beused for diagnostic and prognostic evaluations of vegetation state and functioning. There are already someavailable LAI products which show however some important discrepancies in terms of magnitude and somelimitations in terms of continuity and consistency. This thesis addresses these important issues. First, the nature ofthe LAI estimated from these satellite observations was investigated to address the existing differences in thedefinition of products. Then, different temporal smoothing and gap filling methods were analyzed to reduce noiseand discontinuities in the time series mainly due to cloud cover. Finally, different methods for near real timeestimation of LAI were evaluated. Such comparison assessment as a function of the level of noise and gaps werelacking for LAI.Results achieved within the first part of the thesis show that the effective LAI is more accurately retrievedfrom satellite data than the actual LAI due to leaf clumping in the canopies. Further, the study has demonstratedthat multi-view observations provide only marginal improvements on LAI retrieval. The study also found that foroptimal retrievals the size of the uncertainty envelope over a set of possible solutions to be approximately equal tothat in the reflectance measurements. The results achieved in the second part of the thesis found the method withlocally adaptive temporal window, depending on amount of available observations and Climatology as backgroundestimation to be more robust to noise and missing data for smoothing, gap-filling and near real time estimationswith satellite time series.

Thesis (MscFor)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: The purpose of the study was to investigate the effect of mid rotation fertilizer application on leaf area index (LAI), basal area and volume increment in thinned Pinus radiata stands on the most common soils of the Boland region in the Western Cape. The study was conducted on a range of sites in the Boland region of MTO Forestry Company, chosen to reflect the two most common soil types and a water availability gradient in each soil type. A factorial combination of fertilizer treatments with three levels each for nitrogen (N) at 0, 100 and 200 kg ha-1 and phosphorus (P) at 0, 50 and 100 kg ha- 1 was used. This design was replicated four times across a gradient of water availability for each of the two common soil groups, forming a complete trial series. All replications were laid out in P. radiata stands that had received their mid-rotation thinning prior to treatment implementation. LAI, diameter at breast height and height measurements as well as foliar analysis were determined before the implementation of the study in 2008 and then subsequently at predetermined intervals in 2009 and 2010. Leaf area index and stem volume increment were measured in order to evaluate the influence on growth efficiency. LAI was estimated using the gap fraction method with the use of a ceptometer. Volume increment was calculated using diameter and height measurements and basal area was calculated by means of diameter measurements. The abovementioned growth responses were then used to determine the effect of increased nutrient availability on stand growth. There were no significant interactions detected between any of the factors, N, P and water availability class in their effect on LAI, basal area, volume increment and growth efficiency. LAI increment responded significantly to N and P in the first year but only to P in the second year after treatment. Significant basal area responses to N and P were recorded in the second but not the first year. This might have been due to the fact that trees had to re-build their canopies after thinning before a basal area response could be obtained. For the variables where an analysis of total growth response over the two year period was done, basal area increment and volume increment significantly responded to the application of nitrogen but not to phosphorus. Growth efficiency was not significantly influenced by either nitrogen or phosphorus over the full two year monitoring period. Water availability class consistently and significantly influenced basal area increment, volume increment and growth efficiency over the two year period as well as during year one and year two. The best responses generally occurred as a result of the additive effects of N and P. The growth response did not remain the same across the water availability classes. The wetter sites tended to have greater responses than the drier sites. Although these are still early results, the growth responses could be attributed to an increase in LAI. Nutrient analysis through vector analysis indicated that the additional N and P from fertilizer application were taken up by the trees thereby resulting in greater LAI and increased stem wood production. / AFRIKAANSE OPSOMMING: Die studie het ten doel gestel om die effek van mid-rotasie bemesting op blaar oppervlak indeks (BOI), basale oppervlakte- en volume aanwas te ondersoek in gedunde opstande van Pinus radiata op die mees algemene grondtipes van die Bolandstreek, Wes-Kaapland. Eksperimente is uitgelê oor 'n reeks van groeiplekke in die Bolandstreek wat gekies is om 'n water beskibaarheidsgradient te verteenwoordig oor elk van die twee mees algemene grondtipes. 'n Faktoriaal-kombinasie van kunsmisbehandelings met drie vlakke elk van stikstof [(N) teen 0, 100 en 200 kg ha-1] en fosfor [(P) teen 0, 50 en 100 kg ha-1] is toegedien. Hierdie ontwerp is vier maal herhaal oor 'n gradient van grondwater beskikbaarheid, oor elk van die twee mees algemene grondtipes, om sodoende 'n volledige eksperimentele reeks te vorm. Elke herhaling is uitgelê in 'n P. radiata opstand wat reeds 'n mid-rotasie dunning ondergaan het voor implementering van die kunsmis behandelings. Metings van BOI, deursnee op borshoogte, boomhoogte asook blaarmonsters is geneem voor implementering in 2008 en daarna met vooraf bepaalde tussenposes in 2009 en 2010. Die BOI en stam volume aanwas is bepaal om die effek van behandelings op groeieffektiwiteit te evalueer. Die gaping fraksie tegniek is gebruik om BOI te skat met behulp van 'n sonvlek septometer. Volume aanwas is bereken vanaf deursnee en hoogtemetings en basale oppervlak aanwas vanaf deursnee-metings. Metings van al bogenoemde groeireaksies is gebruik om die effek van verhoogde voedingstof beskikbaarheid op opstandsgroei te evalueer. Daar was geen betekenisvolle interaksies tussen enige van die faktore N, P of water beskikbaarheidsklas met betrekking tot reaksies op BOI, basale oppervlak- en volume aanwas of groei-effektiwiteit nie. Die BOI het betekenisvol gereageer op N en P in die eerste jaar, maar slegs op P in die tweede jaar na behandeling. Basale oppervlakte aanwas is betekenisvol verbeter deur N en P in die tweede jaar maar nie in die eerste jaar nie. Dit is waarskynlik as gevolg van die feit dat opstande eers hul kroondak moes herstel (na dunnings) voordat 'n reaksie in basale oppervlak verkry kon word. Vir die veranderlikes waar 'n analise van die groeireaksie oor die volle twee jaar moniteringsperiode gedoen is, het basale oppervlak- en volume aanwas betekenisvol gereageer op stikstof maar nie op fosfor nie. Groei-effektiwiteit is nie betekenisvol geaffekteer deur N of P oor die volle twee jaar moniteringsperiode nie. Water beskikbaarheidsklas het basale oppervlak en volume aanwas asook groei-effektiwiteit betekenisvol en voortdurend beïnvloed in die eerste en tweede jaar, asook gedurende die volle twee jaar moniteringsperiode. Die beste groeireaksie is oor die algemeen verkry waar N en P gesamentlik toegedien is en waar dus aanvullende reaksies verkry is. Groeireaksies het betekenisvol verskil na gelang van water beskikbaarheidsklas, met die grootste reaksie op die natste groeiplekke. Hoewel hierdie vroeë resultate is, kan ons die meganisme van die reaksie primêr toeskryf aan 'n toename in BOI. Vektor analise van blaar voedingstof vlakke het aangedui dat addisionele N en P na kunsmis toediening opgeneem is, wat die weg gebaan het vir 'n toename in BOI en verhoogde volume aanwas.

Hydroponic system is an important improvement of the potato production process of tuber seeds. There is no enough information about management techniques of hydroponically cultivated potato. A main problem of this production system is the excessive shoot growth, which results in a low propagation rate. Planting density and pruning may change the relationship between shoot and tuber growth, affecting dry matter partitioning. The objective of this work was to study the effect of planting density and pruning in the dry matter partitioning of hydroponically cultivated potato plants to reduce shoot growth an increase tuber dry matter accumulation. One experiment was carried out to study the effect of planting density in the growth and dry matter partitioning of potato plants during spring 2004. Planting densities of 25, 44, 100 and 400 hills.m-2 were evaluated. Another experiment was carried out to study the effect of leaf area restriction with pruning in the dry matter partitioning during fall and spring 2005 growing seasons. The treatments were pruning aerial parts of plants at 10, 20, and 30 cm height and control (with no pruning). Planting density and pruning affected dry matter partitioning of hydroponically cultivated potato plants. Planting density of 100 hills.m-2 results in the highest plant growth and tuber fraction production. This density should be used to the production of potato in hydroponic system. Increasing hill density improves tuber number yield without reducing tuber dry matter production. Pruning plants at 30 cm high is a management practice that can be used to restrict shoot growth of potato plants grown hydroponically, with small yield reduction during spring. / O sistema hidropônico mostra-se como um importante avanço no processo de produção de tubérculos-semente de batata. Existe carência de informações a respeito das técnicas de manejo a serem adotadas no cultivo hidropônico de batata, principalmente por se tratar de uma técnica recente. Dentre os problemas apresentados por esse sistema, destaca-se o excessivo crescimento da parte aérea das plantas, o que afeta a eficiência do processo de multiplicação de tubérculos. A densidade de plantio e a poda da parte aérea interferem no equilíbrio entre o crescimento dos compartimentos vegetativo e generativo, modificando a distribuição dos assimilados na planta. O objetivo deste trabalho foi estudar o efeito da densidade de plantio e da poda da parte aérea sobre a partição de massa seca de plantas de batata cultivadas em hidroponia, visando reduzir o crescimento da parte aérea e aumentar a translocação de massa seca para os tubérculos. Foi conduzido um experimento para estudar o efeito da densidade de plantio no crescimento e na partição de massa seca de plantas de batata durante a primavera de 2004. As densidades de plantio utilizadas foram 25, 44, 100 e 400 covas.m-2. Foi conduzido outro experimento para estudar o efeito de restrições no crescimento da área foliar, através da poda verde, na partição de massa seca no outono e primavera de 2005. Os tratamentos foram a poda da parte aérea sempre que as plantas atingiam a altura de 10, 20 e 30 cm e a testemunha sem poda. A densidade de plantio e a poda verde alteraram a partição de massa seca de plantas de batata cultivadas em hidroponia. O crescimento das plantas e a fração tubérculos atingiram a saturação a partir da densidade de 100 covas.m-2, a qual pode ser empregada para a produção de batata em sistema hidropônico. O incremento da densidade de plantio aumenta o número de tubérculos sem afetar a produção de massa seca de tubérculos. A poda verde a 30 cm de altura pode ser empregada para restringir o crescimento da parte aérea de plantas de batata cultivadas em hidroponia, porém com uma pequena redução de produtividade no cultivo de primavera.

Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-06-11T18:24:51Z No. of bitstreams: 1 SEVERINO PEREIRA DE SOUSA JÚINOR - DISSERTAÇÃO PPGEA 2003..pdf: 9684087 bytes, checksum: ee87f631904d550cbc82b05ad856ba39 (MD5) / Made available in DSpace on 2018-06-11T18:24:51Z (GMT). No. of bitstreams: 1 SEVERINO PEREIRA DE SOUSA JÚINOR - DISSERTAÇÃO PPGEA 2003..pdf: 9684087 bytes, checksum: ee87f631904d550cbc82b05ad856ba39 (MD5) Previous issue date: 2003-12 / O presente estudo foi conduzido em casa de vegetação pertencente á Embrapa algodão, localizada em Campina Grande-PB, durante o período de maio a outubro de 2003. Objetivou-se estudar o crescimento, o desenvolvimento e a produção do algodoeiro BRS Verde irrigado com águas salinas, frequentemente encontradas nos perímetros irrigados . Esse é um problema que cresce anualmente devido ao manejo inadequado da água de irrigação na exploração de culturas socioeconomicamente importantes para o semi-árido. Os tratamentos consistiram-se de dois tipos de água com diferentes proporções de Na e Ca (9.5:0,5 e 6,0:4,0), e seis níveis de condutividade elétrica da água de irrigação - CEa (2,0, 3,5, 5,0, 6,5, 8,0 e 9,5 dS m"1). O delineamento experimental utilizado foi inteiramente casualizado em um esquema de análise fatorial 6 x 2 , resultando em 12 tratamentos com três repetições, constituindo 36 unidades experientais, compostas de vasos plásticos contendo 21 quilos de solo, cultivado com uma planta de algodoeiro. As variáveis número de dias para germinar, percentagem de germinação e índice de velocidade de germinação foram obtidas até aos 12 dias após a semeadura, não sendo estas afetadas pelos tratamentos em estudo. As variáveis do crescimento: número de folhas, altura de planta, diâmetro do caule, área foliar, foram obtidos quinzenalmente até aos 120 dias após a semeadura (DAS), sendo avaliadas nesta mesma época a razão de área foliar e relação raiz/parte aérea, além da fitomassa da parte aérea após a colheita. As taxas de crescimento absoluto e relativo de fitomassa foram obtidas no período de 30 e 90 DAS. O aumento da salinidade da água de irrigação reduziu significativamente o crescimento vegetativo (número de folhas, altura de planta, diâmetro do caule, área foliar, fitomassa da parte aérea), como também os componentes de produção, número e peso médio dos capulhos. No peso médio dos capulhos houve incremento até 4,41 dS m"1, reduzindo a partir daí, 21,37% no nível mais alto (9,5 dS m"1), que ocasionou uma redução de 39,92% da produção, para este mesmo nível salino. Observou também, que o tipo de água não influenciou em nenhumas das variáveis avaliadas. / The present study was carried out under greenhouse conditions at the EMBRAPA Cotton in the municipality of Campina Grande - PB, during the period of May to October 2003. The objective of the work was to study the growth, development and productivity of the green cotton BRS 200 irrigated with water of different salinity leveis. Problem that grows annually due to the inadequate management of the irrigation water in the exploration of socioeconomically important crop for the semi-arid. The treatments consisted of two types of water with varying proportions of Na:Ca (9.5:0.5 e 6.0:4.0), and six leveis of electrical conductivity of the irrigation water - (ECw- 2.0, 3.5, 5.0, 6.5, 8.0 and 9.5 dS m"1). The experimental design used was a completely radomized design in a 6 x 2 factorial scheme, resulted in 12 treatments with three repetitions, constituting of 36 factorial experientais. The variables such as number of days for germination, germination percentage and index of emergence speed were obtained up to 12 days after the seeding. The growth indexes: leaf number, plant height, stem diameter and leaf area, were appraised up to 120 days after seeding, being appraised at the same time the ratio of leaf area and index of root/aerial parts as well as dry weight of the aerial parts. The absolute and relative growth rates were obtained for the 30 and 90 days after the seeding. The salinity of the irrigation water did not affect the percentage of germination (GP) and index of germination speed. However, the increase in the salinity of the irrigation water reduced the vegetative growth significantly (number of leaves, plant height, stem diameter, leaf area, dry weight of the aerial parts). The germination of cotton was influenced by the salinity of the irrigation water, however a GP of 76.66% was obtained in the highest levei. The increase of ECw influenced significantly the leaf number, plant height, stem diameter, leaf area ratio and the dry weight of aerial part as the components of production - the number of capsule and mean weight of capsules. In case of mean weight of capsule, it increased of up to 4.41 dS m"1, reducing there after, 21.37% in the highest levei (9.5 dS m" '). It was also observed that the type of water did not influence any of the appraised variables.

CUTRIM JÚNIOR, José Antônio Alves. Crescimento e morfofisiologia do dossel do capim-tanzânia com três freqüências de desfolhação e dois resíduos pós-pastejo. 2007. 104 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Zootecnia, Fortaleza-CE, 2007 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-08-01T12:50:22Z No. of bitstreams: 1 2007_dis_jaacutrimjunior.pdf: 2648723 bytes, checksum: c68d59cd0a5282b7ed840a24d9a5156c (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-08-01T12:51:06Z (GMT) No. of bitstreams: 1 2007_dis_jaacutrimjunior.pdf: 2648723 bytes, checksum: c68d59cd0a5282b7ed840a24d9a5156c (MD5) / Made available in DSpace on 2016-08-01T12:51:06Z (GMT). No. of bitstreams: 1 2007_dis_jaacutrimjunior.pdf: 2648723 bytes, checksum: c68d59cd0a5282b7ed840a24d9a5156c (MD5) Previous issue date: 2007 / The research was carried through with the objective of evalua ting the growth and morphophysiological characteristics in canopy of Tanzania grasses under intermittent grazing with three defoliation frequencies and two post-grazing residues. The research was driven in the advanced field of the Nucleu s of Teaching and Study in Forragicultura- NEEF/DZ/CCA/UFC, located in Experi mental Farme it is Worth of Curú- FEVC/CCA/UFC, in Pentecoste/CE. The method of used grazing was it of intermittent grazing with tax of variable capacity with peri od of pastejo of four days. The split plot was it entirely randomizer in a factorial arrangemen t 3 x 2 being, three defoliation frequencies of the pasture established in f unction of the necessary time fo r the restoration of an area index to foliate that it intercepts 85; 95 a nd 97% of the photosyntheti cally active radiation (PAR) and two residues powder grazing, constitu ted of two residual IAF's, 1.0 and 1.8. Such variables were certain through the An alisador PAR/LAI in Agricultura DECAGON PAR-80 (DECAGON Devices, Inc ., Pullman, Washington-use s). The interval among pastejo went larger for PD 97% IRFA (34 days) and for IAFr 1.0 (28.2 days). The curve of evolution of IRFA came asymptot ic in relation to age of re growth of the grass, being stabilized at the level of 95% interception PA R. Already the curve of evolution of IAF was growing, even after reaching critical IAF. Ther e was effect of IRFA, of IAFr (P<0.05) and of the interaction IRFA x IAFr (P<0.15) on TAlF1/TAlF2. Para TAlF was noticed effect of IRFA and of IAFr (P<0.05), a nd smallest interception (85% IRFA) and largest IAFr (1.8) they were the ones that obtaine d larger TAlF. TAlH suffered e ffect just of IRFA (P<0.05). There was effect of IRFA and of IAFr (P<0.05) on TST, and most lingering IRFA (1.20 cm/perxdia) and IAFr 1.0 (0.96 cm/perxdia) that had largest TST. The interception of 85% (0.12 leaf/days), as well as IAFr 1.8 (0.11 l eaf/days) they obtaine d the largest values of TApF. Phylochron suffered e ffect of IRFA (P<0.05) and of the interaction IRFA x IAFr (P<0.15) with 11.05 days/leaf for 95% IRFA an d the interaction happening for 85% IRFA. There was effect just of IRFA (P<0.05) for TAF. There was e ffect of IRFA (P <0.05) on IAF. The height suffered so much effect of IRFA, as of IAFr (P<0.05). MSFT and MSFV suffered effect just of IRFA (P<0.05). MSFM suff ered effect just of the interac tion IRFA x IAFr (P<0.15), happening for 85% IRFA. There was effect of the interaction IRFA x IAFr about the relationship MV/MM (P<0.15). There was effect just of IRFA (P<0.05) on MSLV and MSCV. There was effect of IAFr (P<0.05) about the relationship Leaf/stem. / A pesquisa foi realizada com o objetivo de avaliar o crescimento e as características morfofisiológicas do dossel de Panicum maximum cv. Tanzânia sob lotação rotativa com três períodos de descanso e dois resíduos pós-pastejo. A pesquisa foi conduzida no campo avançado do Núcleo de Ensino e Estudo em Forragicultura-NEEF/DZ/CCA/UFC, localizado na Fazenda Experimental Vale do Curú-FEVC/CCA/UFC, em Pentecoste/CE. O método de pastejo utilizado foi o de lotação rotativa com taxa de lotação variável com período de pastejo de quatro dias. O delineamento foi o inteiramente casualizado em um arranjo fatorial 3 x 2 sendo, três períodos de descanso do pasto estabelecidos em função do tempo necessário para a restauração de um índice de área foliar que intercepte 85; 95 e 97% da radiação fotossinteticamente ativa (RFA) e dois resíduos pós-pastejo, constituídos de dois IAF’s residuais, 1,0 e 1,8. Tais variáveis foram determinadas por meio do Analisador PAR/LAI em Agricultura DECAGON PAR-80 (DECAGON Devices, Inc., Pullman, Washington-USA). O intervalo entre pastejo foi maior para PD 97% IRFA (34 dias) e para o IAFr 1,0 (28,2 dias). A curva de evolução da IRFA apresentou-se assintótica em relação a idade de rebrotação do capim, estabilizando-se ao nível de 95% IRFA. Já a curva de evolução do IAF foi crescente, mesmo após atingir o IAF crítico. Houve efeito da IRFA, do IAFr (P<0,05) e da interação IRFA x IAFr (P<0,15) sobre a TAlF1/TAlF2. Para a TAlF observou-se efeito da IRFA e do IAFr (P<0,05), sendo que a menor interceptação (85% IRFA) e o maior IAFr (1,8) foram os que obtiveram maiores TAlF. A TAlH sofreu efeito apenas do PD (P<0,05). Houve efeito da IRFA e do IAFr (P<0,05) sobre TST, sendo que a maior interceptação (1,20 cm/perxdia) e o IAFr 1,0 (0,96 cm/perxdia) que tiveram a maior TST. A percentagem de 85% IRFA (0,12 folha/dia), assim como o IAFr 1,8 (0,11 folha/dia) obtiveram os maiores valores de TApF. O Filocrono sofreu efeito da IRFA (P<0,05) e da interação IRFA x IAFr (P<0,15) com 11,05 dias/folha para 95% IRFA e a interação ocorrendo para 85% IRFA. Para TAF houve efeito apenas da IRFA (P<0,05). Houve efeito da IRFA (P<0,05) sobre o IAF. A Altura sofreu efeito tanto da IRFA quanto do IAFr (P<0,05). A MSFT e a MSFV sofreram efeito apenas da IRFA (P<0,05). A MSFM sofreu efeito apenas da interação IRFA x IAFr (P<0,15), ocorrendo na interceptação de 85%. Houve efeito da interação IRFA x IAFr sobre a relação MV/MM (P<0,15). Houve efeito apenas do IRFA (P<0,05) sobre a MSLV e MSCV. Houve efeito do IAFr (P<0,05) sobre a relação Folha/colmo. A DPP sofreu efeito da IRFA, dos IAFrs (P<0,05) e da interação IRFA x IAFr (P<0,15). Houve efeito apenas da IRFA (P<0,05) sobre o número de Folhas/perfilho. No que tange as variáveis estruturais pós pastejo observou-se um efeito do IAFr (P<0,05) sobre a IRFA. A Altura residual sofreu apenas efeito do IAFr (P<0,05). A MSFT e a MSFM sofreram efeito da IRFA, dos IAFrs (P<0,05) e da interação IRFA x IAFr (P<0,15). A MSFV e a MSLV sofreram efeito dos IAFrs (P<0,05). Houve interação entre o IRFA x IAFr (P<0,15) para a relação MV/MM. Houve efeito da IRFA e IAFrs (P<0,05) sobre a MSCV. Houve efeito da IRFA (P<0,05) sobre a relação Folha/colmo. A DPP apresentou efeito da IRFA, dos IAFrs (P<0,05) e da interação IRFA x IAFr (P<0,15). O número de Folhas/perfilho estimado pelo método morfogênico subestimou os valores obtidos pelo método visual de campo, mas sendo que apresentou valores confiáveis e na mesma tendência do número de Folhas/perfilho obtida pelo método visual. O mesmo observa-se para os métodos de obtenção dos valores da DPP onde o método do quadrado superestimou o método do transceto, mas apresentando valores dentro da realidade da forrageira e do método de pastejo utilizado, podendo perfeitamente ser empregado, facilitando a obtenção dos valores dessa variável. Valores da TPF e da TAF estimados pelo método agronômico superestimaram os valores obtidos pelo método morfogênico.

Native to Europe and Asia, Lythrum salicaria is an invasive element on some other continents. Plants in the invaded areas are more robust, higher, and generally more successful compared to individuals in their original area. Based on my results these characteristics cannot be explained by neither higher photosynthesis, chlorophyll and carotenoid mass, nor specific leaf area.

This study examines the role of deffensive host-plant traits in structuring the community of leaf-chewing insects living on willows. Host-plant phylogeny was reconstructed and leaf morphology and content of three different groups of secondary metabolites were measured. Relationships between defensive leaf traits were examined and their influence on insect community structure was analyzed.