Remote sensing provides temporal, spectral and spatial information covering a wide area. Therefore, it has great potential in offering a detailed quantitative determination of the leaf area index (LAI) and other crop parameters in precision agriculture. The spatially differentiated assessment of LAI is of utmost importance for enabling an adapted field management, with the aim of increasing yields and reducing costs at the same time. The scientific focus of this work was the investigation of the potential of hyperspectral remote sensing data of different spectral resolutions, which were acquired at different spatial scales, for a precise assessment of wheat LAI. For this reason, three research experiments were conducted: 1) a comparison of different empirical-statistical regression techniques and their capabilities for a robust LAI prediction; 2) a determination of the required spectral resolution and important spectral regions/bands for precise LAI assessment; and 3) an investigation of the influence of the ground sampling distance of remote sensing images on the quality of spatial LAI predictions. The first part of this thesis compared three empirical-statistical regression techniques – namely, partial least-squares regression (PLSR), support vector regression (SVR) and random forest regression (RFR) – and their achieved model qualities for the assessment of wheat LAI from field reflectance measurements. In this context, the two different validation techniques – leave-one-out cross-validation (cv) and independent validation (iv) – were applied for verifying the accuracy of the different empirical-statistical regression models. The results clearly showed that model performance markedly depends on the validation technique used to assess model accuracy. In the case of leave-one-out cross-validation, SVR provided the best results, while PLSR proved to be superior to SVR and RFR when independent validation was applied. In the second part of this thesis, the spectral characteristics of the hyperspectral airborne sensor aisaDUAL (98 spectral bands) and the upcoming hyperspectral satellite mission EnMAP (204 spectral bands) were investigated to show their capability regarding the precise determination of wheat LAI. Moreover, the feature selection algorithm RReliefF, combined with a randomized sampling approach, was applied to identify the spectral bands that were most sensitive to changes in LAI. The results demonstrated that only three spectral bands of aisaDUAL, as well as EnMAP, at specific locations within the investigated spectral range (400–2,500 nm) were necessary for an accurate LAI prediction. The third part of this thesis dealt with the influence of the spatial resolution of aisaDUAL (3 m) and simulated EnMAP (30 m) image data on the assessment of wheat LAI. While the ground sampling distance (GSD) of aisaDUAL allowed a robust regression model calibration and validation, LAI predictions based on simulated EnMAP image data led to poor results because of the distinct difference in size between the EnMAP pixels (900 m2) and the sampled field plots (0.25 m2) for which the LAI was measured. In order to enable a more precise determination of wheat LAI from EnMAP image data, the two different approaches of image aggregation and image fusion were examined. In this context, the fusion approach has proven to be the more suitable method, which allowed a more accurate LAI prediction compared to the results based on the EnMAP data with a GSD of 30 m. In summary, the findings of the research reported in this thesis demonstrated that the accuracy of spatial LAI predictions from remote sensing data depends on several factors. Besides the applied empirical-statistical retrieval- and validation method, the spatial and spectral characteristics of the used image data sets played an important role. With the forthcoming hyperspectral satellite missions (e.g., EnMAP, HyspIRI), the area-wide assessment of LAI and other crop parameters (e.g., biomass, chlorophyll content) will be strongly supported. The moderate spatial resolutions of these satellites systems, however, require a combined use with spatial higher resolution multi- or superspectral satellite data (e.g., RapidEye, Sentinel-2). This multisensoral approach offers great potential for the prompt identification of spatial variations in crop conditions on sub-field scale, which is a mandatory prerequisite for precision agricultural applications.

Commercially available leaf area index (LAI) meters are tools that can be used in making insect management decisions. However, proper technique must be determined for LAI estimation, and accuracy must be validated for the meters. Full-season soybean require LAI values of at least 3.5 to 4.0 by early to mid-reproductive developmental stages to achieve maximum yield potential, but the relationship between double-crop soybean LAI and yield is unknown. This research (1) evaluated minimum plot size requirements for mechanically defoliated soybean experiments using the LAI-2000 Plant Canopy Analyzer, (2) compared LAI estimates among LAI-2000 detector types which respond to different wavelengths of light, (3) compared LAI-2000 estimates with directly determined LAI values for 0, 33, 66, and 100% mechanical defoliation levels, (4) used linear and non-linear models to describe the response of full-season and double-crop soybean yields to reductions in LAI through mechanical defoliation, and (5) evaluated the response of double-crop soybean yields to reductions in LAI through insect defoliation. The minimum plot size for obtaining accurate LAI estimates of defoliated canopies in soybean with 91 cm row centers is four rows by 2 m, with an additional 1 m at the ends of the two middle rows also defoliated. The wide-blue detector, which is found in newer LAI-2000 units and responds to wavelengths of light from 360 to 460 nm, gave higher LAI estimates than the narrow-blue detector, which responds to light from 400 to 490 nm. The unit with the narrow-blue detector gave estimates equal to directly determined LAI in two of three years for 0, 33, and 66% defoliation levels, while the units with the wide-blue detectors gave estimates higher than directly determined LAI in the two years that they were studied, except for a few accurate 33% defoliation estimates. Therefore, the LAI-2000 usually provides reasonable estimates of LAI. Yield decreased linearly with LAI when LAI values were below 3.5 to 4.0 by developmental stages R4 to R5 in both full-season and double-crop soybean. Usually, there was no relationship between yield and LAI at LAI values greater than 4.0. There was an average yield reduction of 820 ± 262 kg ha⁻¹ for each unit decrease in LAI below the critical 3.5 to 4.0 level; maximum yields ranged from 1909 to 3797 kg ha⁻¹. Insect defoliators did not defoliate double-crop soybean plots to LAI levels less than 4.0, and there was no yield difference between insect-defoliated and control plots. Therefore, double-crop soybean that maintains LAI values above the 3.5 to 4.0 critical level during mid-reproductive developmental stages is capable of tolerating defoliating pest / Ph. D.

The site-specific management of alfalfa has not been well-evaluated, despite the economic importance of this crop. The objectives of this work were to i) characterize the effects of soil moisture deficits on alfalfa and alfalfa yield components and ii) evaluate the use of canopy reflectance patterns in measuring treatment-induced differences in alfalfa yield. A randomized complete block design with five replicates of subsurface drip irrigation (SDI) and rainfed treatments of alfalfa was established at the University of Kentucky Animal Research Center in 2003. Potassium, as KCl, was broadcast on split-plots on 1 October 2004 at 0, 112, 336, and 448 kg K2O ha-1. In the drought year of 2005, five harvests (H1 - H5) were taken from each split-plot and from four locations within each SDI and rainfed plot. One day prior to each harvest, canopy reflectance was recorded in each plot. Alfalfa yield, yield components, and leaf area index (LAI) were determined. In 2005, dry matter yields in two harvests and for the seasonal total were increased (Pandlt;0.05) by SDI, but SDI did not affect crown density. Herbage yield was strongly associated with yield components but yields were most accurately estimated from LAI. Canopy reflectance within blue (450 nm), red (660 nm) and NIR bands were related to LAI, yield components, and yield of alfalfa and exhibited low variance (cv andlt; 15%) within narrow ( 0.125 Mg ha-1) yield ranges. Red-based Normalized Difference Vegetation Indices (NDVIs) and Wide Dynamic Range Vegetation Indices (WDRVIs) were better than blue-based VIs for the estimation of LAI, yield components, and yield. Decreasing the influence of NIR reflectance in VIs by use of a scalar (0.1, 0.05, or 0.01) expanded the range of WDRVI-alfalfa yield functions. These results indicate that VIs may be used to estimate LAI and dry matter yield of alfalfa within VI-specific boundaries.

An energy-based model accounting for snow accumulation and snowmelt in a coniferous forest and in an open area An energy balance approach was used to simulate snow water equivalent (SWE) evolution in an open area, forest clearing and coniferous forest during winter seasons 2011/12 and 2012/13 in the Bystřice River basin (Krušné Mountains). The aim was to describe the impact of vegetation on snow accumulation and snowmelt under different forest canopy structure and density of trees. Hemispherical photographs were used to describe the forest canopy structure. Energy balance model of snow accumulation and melt was set up. For forest sites the snow model was altered for accounting the effects of the forest canopy on the driving meteorological variables of the snow model. Leaf area index derived from 32 hemispherical photographs of the vegetation and sky was used for forest influence implementation in the snow model. The model was evaluated using snow depth and SWE field data measured at 16 localities in winter seasons from 2011 to 2013. The model was able to reproduce the SWE evolution in both winter seasons beneath the forest canopy, forest clearing and open area with correlations to observations ranging from 0.16 to 0.99. The SWE maximum in forest sites is by 18% lower than in open areas and forest...

A cobertura de dossel em uma floresta controla a quantidade, a qualidade e a distribuição da incidência de radiação solar, o que vem a refletir em diferentes níveis de umidade do solo, promovendo a interceptação das chuvas, consequentemente, reduzindo o seu impacto do solo. Além disso, a estrutura vegetal e a densidade do dossel condicionam não apenas o regime de radiação, mas também as trocas de energias e gases entre floresta e atmosfera. Este trabalho teve como objetivo comparar o uso do densiômetro, densitômetro, quadro reticulado e fotografias hemisféricas na obtenção da densidade do dossel visando encontrar uma metodologia de baixo custo e que garanta a mesma eficiência dos resultados de densidade de dossel obtidos de fotografias hemisféricas com máquina fotográfica. Resultados significativos foram obtidos para o uso do quadro reticulado, do densiômetro e da lente hemisférica fisheye clip para celular. / The canopy cover in a forest controls the solar radiation incidence quantity, quality and distribution, which it comes to reflect different levels of soil moisture, promoting the interception of rainfall and, thereafter, reducing its impact soil. Furthermore, plant canopy structure and density promotes not only the radiation system, but also energy and the exchange of gases between atmosphere and forest. This study aimed to compare the densiometer, densitometer lattice frame and hemispherical photographs uses on getting the canopy density in seeking a low methodology costs and guaranteeing the same efficiency of canopy density results hemispherical photographs with camera . This work presented significant results as the lattice frame, densiometer and hemispheric fisheye lens clip for mobile uses.

A alta demanda por madeira de eucalipto para diversas finalidades traz a necessidade da expansão de plantios para áreas em condições de déficit hídrico, o que leva o interesse de entender os processos fisiológicos relacionados ao crescimento da árvore, para possibilitar uma alta produtividade das florestas nessas áreas. Com base nessas informações, o objetivo deste trabalho foi avaliar o efeito da variação de níveis de restrições hídricas em clones de Eucalyptus spp. plantados em diferentes condições edáficas, pelo estudo das respostas ecofisiológicas, para isso foram instalados em janeiro 2012 dois experimentos na Estação Experimental de Ciências Florestais de Itatinga (EECFI) pertencente a Escola Superior de Agricultura \"Luiz de Queiroz\" (ESALQ) - USP, o experimento 1 foi instalado no solo classificado como Latossolo vermelho distroférrico típico A moderado textura argilosa (LVdf) e o experimento 2 no solo Latossolo vermelho distrófico típico A moderado textura argilosa (LVd-1).Cada experimento foi implantado em blocos casualizados em arranjo fatorial de 6 x 3, seis clones de eucalipto (COP 1404, COP 1407, AEC 1528, AEC 0042, AEC 0224, AEC 0144) e três espaçamentos (3m x1m, 3mx2m, e 3mx4m), com seis repetições, e parcelas quadradas constituídas por 25 plantas, sendo as nove plantas centrais consideradas como a área útil de medição. Foram realizadas avaliações das variáveis: DAP (cm), altura total (m), comprimento da copa (m) e índice de área foliar (IAF m2/m2) trimestralmente, no período de 21 até 37 meses de idade para as variáveis altura total e DAP, e o comprimento da copa e IAF a partir do mês 27. Para a mensuração do IAF foram utilizados dois equipamentos LAI-2000, onde a coleta de dados foi fora e sob o dossel. O folhedo foi coletado mensalmente em todas as parcelas. A avaliação da eficiência e uso de água foi aos 29 e 35 meses, analisando área foliar e as caraterísticas estomáticas em quatro blocos, nos quais três árvores foram amostradas sistematicamente. Para avaliação no incremento de diâmetro no tronco, se instalaram faixas dendrométricas em duas árvores por parcela e as leituras foram quinzenais, sendo correlacionadas com variáveis climáticas no período de 15 e 45 dias de defasagem. Os clones que apresentaram melhor desenvolvimento e estratégia do uso da água foram AEC 1528, AEC 0144 e AEC 0042 obtendo como respostas: maior DAP, altura total, comprimento da copa, área foliar, diâmetro estomático, e menor IAF e concentração de estômatos. Em relação ao peso de folhedo depositado verificou-se que a tendência de deposição oscilou no decorrer do tempo em função da fenologia da planta. Na dinâmica de crescimento cambial os incrementos apresentaram correlações com as variáveis climáticas, principalmente com a precipitação pluviométrica, quanto maior a defasagem maior a correlação. Correlacionando todas as variáveis, os clones apresentaram distintos padrões de respostas ecofisiológicas. / Eucalypts plantations are expanding to drought áreas in Brazil in order to attend the high demand of eucalypts wood for various purposes. Therefore, the understanding the physiological process related to tree growth in this condition is one of the research priorities. This study aimed to evaluate the effect of ecophysiological responses to water restrictions levels in growth of Eucalyptus spp clones, planted in different soil conditions. The two field experiments were planted in January 2012 at the Itatinga Experimental Station, College of Agriculture \"Luiz de Queiroz\" (ESALQ), São Paulo State University. Experiment 1 was planted on a site which the soil is classified as \"A moderate typical dystrophic Red Latosol with clay texture (LVdf)\" and experiment 2 on \"A moderate typical dystrophic Red Latosol with clay texture (LVd- 1)\". The experiments were established in a randomized block design with factorial 6 x 3 arrangement [six eucalypts clones (COP 1404, COP 1407, AEC 1528 AEC 0042, AEC 0224, AEC 0144) and three spacings (3m x1m, 3mx2m and 3mx4m)], with six replications, and square plots (5x5 trees). The measurements were carried out on the nine central trees. From the 21 to 37 months of age, the following variables were assessed every three months: DBH (diameter at breast height in cm), height (m) and crown length (m). Leaf area index (LAI m2 / m2) was evaluated every three months after 27 months of age. Two LAI-2000 equipments were used to measure the LAI, one under and another out of the canopy. Litter was collected monthly on all plots. The efficiency of water use was evaluated at 29 and 35 months of age, based on leaf area and stomatal characteristics of samples collected in three trees sampled systematically in four blocks. Dendrometer belts were used to evaluate the diameter growth of two trees per plot. Data collected fortnightly from dendrometers belts were correlated with climatic variables with 15 and 45-da lags. AEC 1528, AEC 0144 and AEC 0042 clones showed higher DBH, total height, crown length, leaf area, stomatal diameter and lower IAF and stomatal concentration, showing better strategy of water use and growth. Deposition of litter fluctuated over time and varied with the tree phenology. Cambium growth dynamics correlated with climate variables, especially with the rainfall. Higher correlations were observed with higher measured lag. Clones showed distinct patterns of ecophysiological responses when the correlations of all variables were considered.

O almeirão e produzido no Brasil principalmente por pequenos produtores, que geralmente produzem outras culturas hortícolas. O almeirão e principalmente utilizado na alimentação humana, porem com potencial para produção de inulina e também com potencial para alimentação animal. O objetivo deste trabalho foi avaliar o efeito da aplicação de porcentagens da evapotranspiração da cultura por irrigação na produção vegetal do almeirão cultivar \"Folha Larga\" cultivado em casa de vegetação. Dois experimentos consecutivos foram executados em delineamento de blocos inteiramente aleatorizados submetidos a cinco porcentagens de evapotranspiração de cultura (ETc): 60, 80, 100, 120 e 140% aplicadas por irrigação via gotejo. A área experimental foi constituída de 45 parcelas de 1,3 m2 cada, sendo que cada parcela possuía uma válvula solenoide para controlar o tempo de funcionamento da irrigação, totalizando nove repetições por tratamento. A umidade do solo foi monitorada por meio de três sondas de TDR (Time Domain Reflectometry), instaladas a 0,05, 0,30 e 0,50 m de profundidade. As condições meteorológicas foram monitoradas utilizando-se uma estação meteorológica, a qual registrava medidas de umidade relativa do ar, temperatura do ar, radiação solar e velocidade do vento, realizando medidas a cada segundo e armazenando os dados a cada 15 minutos. A partir dos dados meteorológicos, estimou-se a evapotranspiração de referencia pelo método de Penman-Monteith FAO-56, e a evapotranspiração da cultura, utilizando-se um coeficiente de cultura médio igual a 0,76. Foram realizados dois experimentos consecutivos, aplicando-se as porcentagens de ETc durante todo o cultivo do almeirão. As variáveis medidas e analisadas foram: altura de plantas (cm), numero de folhas por planta, massa fresca da parte aérea (g), massa fresca por folha (g folha-1), massa seca da parte aérea (g), umidade da parte aérea (%), área foliar (cm2), comprimento foliar (cm) e largura foliar. Utilizou-se os dados de cada tratamento para se realizar a analise de variância conjunta e teste de media ou analise de regressão, sendo que apenas para as variáveis de massa fresca e massa seca da parte aérea foi possível ajustar equações que representassem os dados médios dos dois experimentos. Observou-se que os dados de massa fresca da parte aérea apresentaram-se diretamente proporcionais ao aumento da porcentagem de evapotranspiração, sendo que o tratamento de 140% da ETc foi o que resultou em maior produção de massa fresca da parte aérea, aproximadamente 31,6% superior a produção do tratamento de 60% da ETC. Quanto aos dados de massa seca da parte aérea, observou-se que a porcentagem de 111,1% da evapotranspiração foi a que obteve maior produção de massa seca da parte aérea, sendo 29,3% maior do que a produção em massa seca do tratamento de 60% da evapotranspiração e 9,35% maior do que a obtida no tratamento de 140% da ETc. A partir dos dados de área foliar, comprimento e largura das folhas do primeiro experimento, foi possível ajustar quatro modelos com resíduos tendendo a normalidade e homocedásticos, os quais foram testados pelo método de Bland-Altman com os dados de área, comprimento e largura foliar do segundo experimento. / Chicory is grown in Brazil mainly by small landowners, which usually product other horticultural crops. Chicory is mainly used for human feeding, but it has potential for inuin production and also potential for animal feeding. This study aimed at evaluating the effect of applying percentages of crop evapotranspiration by irrigation over vegetable production of \"Folha Larga\" chicory cultivar grown in greenhouse. Two experiments were performed in the of completely randomized design under five percentages of crop evapotranspiration (ETc): 60, 80, 100, 140% applied by drip irrigation. The experimental area was constituted of 45 plots of 1.3 m2 each, each plot had a solenoid valve to control the duration of the irrigation, totaling nine plots for each treatment. Soil humidity was monitored through three TDR probes (Time Domain Reflectometry), installed at 0.05, 0.30, and 0.50 m depth. The meteorological conditions were monitored using a meteorological station, which recorded measures of relative air humidity, air temperature, solar radiation and wind speed, taking measures at each second and registering the data at each 15 minutes. From meteorologic data, the reference evapotranspiration was estimated by the Penman-Monteith FAO-56 method, and the crop evapotranspiration, using an average crop coefficient equal to 0.76. Two consecutive experiments were performed, applying the percentages of ETc during all the chicory growth period. The measured and analyzed variables were: plant height (cm), number of leaves per plant, plant fresh mass (g), fresh mass by leaf (g leaf-1), plant dry mass (g), plant humidity (%), leaf area (cm2), leaf length (cm) and leaf width (cm). The data of each treatment was used to perform the joint analysis of variation and average test or regression analysis, resulting that only for the variables of leaves fresh and dry weight it was possible to adjust equations to represent the mean values of both experiments. It was observed that the plant fresh weight presented itself directly proportional to increments of percentages of evapotranspiration, being that the treatment of 140% of ETc was the treatment that resulted higher production of plant fresh weight, approximately 31.6% higher than the production obtained from treatment of 60% of evapotranspiration. For the data of plant dry mass, it was observed that the percentage of 111.1% of evapotranspiration was the one that obtained higher values of plant dry weight, being 29.3% higher than the production of plant dry mass obtained with the treatment of 60% of ETc and 9.35% higher than the one obtained with the treatment of 140% of evapotranspiration. From the data of leaf area, length and width of the first experiment, was possible to adjust four models with residuals with normal tendency and homocedastic, which were tested by the Bland- Altman method with the data of leaf area, length and width of the second experiment.

O tratamento de esgoto gera um resíduo, o lodo de esgoto, que tem potencial para promover o crescimento de plantas e aumentar a produtividade de cultivos. O objetivo geral do trabalho desenvolvido foi avaliar como esse resíduo aplicado em plantações de eucalipto altera os estoques de C e N, aspectos do processo fotossintético, da área e nutrientes foliares. O estudo foi conduzido na estação experimental de Itatinga - ESALQ/USP, com aplicação de doses até 40 t/ha de biossólido para cultivo de Eucalyptus grandis. Considerando a biomassa total acima do solo, os eucaliptos que receberam 10 t/ha de biossólido + K e P mineral (10+KP) e adubação mineral completa (AD) produziram, em média, 107,5 t/ha, 63% a mais do que a testemunha; além de maiores valores de conteúdo de C e N na biomassa. Não houve diferenças significativas entre os tratamentos para os conteúdos totais de C (F = 1,3450; p = 0,3096), N (F = 1,2183; p = 0,3536) e conteúdo de N mineral (F = 0,5192; p = 0,7218) no solo. Apenas o C do solo determinado por oxidação úmida foi alterado. A dose de 10 t/ha propiciou aumentos no C Walkley e Black em relação às maiores doses, mostrando que o desenvolvimento das árvores é mais importante para propiciar entradas de material orgânico no sistema do que a própria aplicação do biossólido. A utilização de biossólido alcalino, em superfície, propiciou baixas taxas de decomposição aos 5 anos após aplicação e não contribuiu para aumentar os estoques totais de C e N no solo. Os eucaliptos que receberam nutrientes, seja pela adubação mineral, seja pela aplicação de biossólido apresentaram maior área foliar. A diferença entre o maior IAF (4,3), do tratamento 40+K, e o controle superou uma unidade. As doses de biossólido polimerizado foram correlacionadas positivamente com os teores foliares de N, P, S, e Zn e com a clorofila do eucalipto com 3 meses de idade. Esse biossólido pode aumentar a fotossíntese líquida, quando as medições são realizadas no período da manhã, sendo também capaz de promover aumentos na eficiência do uso da água e no desenvolvimento de eucaliptos jovens. / The wastewater treatment generates a residue, the sewage sludge, that has potential to promote plants growth and to increase its productivity. The general aim of this research was to evaluate how the applied residue in eucalypt plantations modify C and N stocks, aspects of the photosynthetic process, leaf area and leaf nutrients. The study was developed at the experimental station of Itatinga - ESALQ/USP. The experiment was installed with application of rates up to 40 t/ha of biosolids in Eucalyptus grandis plantation. Considering the total biomass above the soil, the eucalypts that received 10 t/ha of biosolids + K and P mineral (10+KP) and complete mineral fertilization (AD) produced, on average, 107.5 t/ha, which represents 63% more than control treatment and larger values of C and N contents in the biomass. There were not significant differences among the treatments for total contents of C (F = 1.3450; p = 0.3096), N (F = 1.2183; p = 0.3536) and mineral N (F = 0.5192; p = 0.7218) in the soil. Just the soil carbon content, determined by wet oxidation, was altered. The 10 t/ha biosolids rate increased the Walkley and Black C in relation to the largest doses, showing that trees development is more important to input organic material in the system than the biosolids application. The alkaline biosolids application to the soil surface resulted in low decomposition rates, 5 years after application, and did not contribute to increase C and N total stocks in the soil. The eucalypts that received nutrients even by mineral fertilization or by biosolids application, presented larger leaf area. The difference between the higher LAI (4.3) observed (treatment 40+K) and the control treatment was one unit. The polymeric biosolids rates were positively correlated with N, P, S, and Zn concentrations and with chlorophyll in eucalypts leaves at 3 months of age. The studied biosolid can increase net photosynthesis, being also capable to promote the water use efficiency and young eucalypts development.

Entender os mecanismos de defesa das plantas de crisântemo em resposta à deficiência hídrica é importante no processo produtivo desta cultura. O objetivo neste trabalho foi determinar a resposta da transpiração e do crescimento foliar, de cultivares de crisântemo (Dendranthema grandiflora Tzvelev.), ao conteúdo de água disponível em substrato, representado pela fração de água transpirável em substrato (FATS). Foram realizados dois experimentos, no setor de floricultura do Colégio Politécnico da UFSM, utilizando-se o delineamento inteiramente casualizado, sendo um no fim da primavera de 2011, com aplicação dos tratamentos a partir de 09/12/2011 - e um no inverno de 2012, com aplicação dos tratamentos a partir de 07/07/2012. As plantas foram cultivadas em vasos de 2,8 litros, preenchidos com substrato e dispostos no interior de uma casa de vegetação com controle de temperatura. As cultivares de crisântemo utilizadas foram a Cherry White (de vaso), Repin Bronze (de corte), Apple Valley (de vaso) e Calábria (de corte). A FATS, a transpiração e o crescimento foliar foram determinados diariamente durante o período de imposição da deficiência hídrica em cada experimento. A FATS crítica no crisântemo que começa a afetar a transpiração, indicativo do início do fechamento estomático, é de 0,63 para a cultivar Cherry White; 0,60 para a cultivar Repin Bronze; 0,53 para a cultivar Apple Valley; e 0,51, para a cultivar Calábria. A redução do crescimento foliar inicia com um valor de FATS crítica de 0,67 para a cultivar Cherry White; 0,69 para a cultivar Repin Bronze; 0,59 para a cultivar Apple Valley e 0,54, para a cultivar Calábria. As cultivares Cherry White e Repin Bronze apresentam maior tolerância ao déficit hídrico do que as cultivares Apple Valley e Calábria. O crescimento foliar começa ser reduzido com um valor de FATS crítica maior do que o valor de FATS crítica em que a transpiração começa a ser reduzida. A deficiência hídrica afeta negativamente as variáveis de crescimento e de desenvolvimento de cultivares de crisântemo. / Understand the defense mechanisms of plants of chrysanthemum in response to water stress is important in the production process of this crop. The objective of this study was to determine the response of the plant to transpiration and leaf growth of chrysanthemum cultivars (Dendranthema grandiflora Tzvelev.), related to the available water content in the substrate, represented by the fraction of transpirable substrate water (FTSW). Two Greenhouse experiments were conducted in the flower sector of the Polytechnic College UFSM, using a completely randomized design. One started end of spring of 2011, with application of treatments on 09/12/2011 and the second in winter 2012, with application of treatments on 07/07/2012. Plants were grown in 2.8 liter pots filled with substrate and arranged inside a greenhouse with temperature control. The chrysanthemum cultivars were Cherry White (potted), Repin Bronze (for cut), Apple Valley (potted) and Calabria (for cut). The FTSW, transpiration and leaf growth were determined daily during the period of imposition of water deficit in each experiment. The threshold FTSW for Chrysanthemum that begins to affect transpiration, is an indicative of early stomatal closure and was 0.63 for the cultivar Cherry White, 0.60 for Repin Bronze, 0.53 for Apple Valley and 0.51, for Calabria. Leaf growth began to be reduced at a threshold FTSW of 0.67 for Cherry White, 0.69 for Repin Bronze, 0.59 for Apple Valley and 0.54, for Calabria. Cultivars Cherry White and Bronze Repin proved to be more tolerant to water deficit than the cultivars Apple Valley and Calábria. The reduced leaf growth starts with a threshold FTSW value larger than the threshold FTSW value related to reduced transpirations. The water deficit negatively affected the variables of growth and development of the chrysanthemum cultivars.

A videira \'Niágara Rosada\' é a principal cultivar de mesa produzida no estado de São Paulo. Essa cultivar é conduzida preferencialmente no sistema em espaldeira pelo baixo custo de implantação e por permitir manipulação do dossel através de podas. A estrutura do dossel afeta diretamente o desenvolvimento da planta, modificando a superfície foliar exposta à radiação solar que é responsável pelo acúmulo de carboidratos no sistema radicular. A quantidade de carboidratos de reserva pode influenciar diretamente a fertilidade das gemas, o vigor da planta e a produtividade do ciclo seguinte. O presente trabalho teve como objetivo avaliar o efeito da superfície foliar de videiras \'Niágara Rosada\', conduzidas no sistema em espaldeira com diferentes comprimentos dos ramos produtivos, na produção e no acúmulo de carboidratos de reserva no sistema radicular. Realizou-se dois experimentos com videiras conduzidas em sistema de espaldeira, nos ciclos produtivos de 2016 e 2017, na cidade de Piracicaba-SP. No primeiro experimento, após os ramos atingirem 100 cm de altura, foi realizado o desponte nas alturas de 80 e 60 cm. O segundo experimento, foi composto por cinco tratamentos: Desponte com 100 cm de altura, desponte com 70 cm após o ramo alcançar 100 cm de altura, desponte com 50 cm após o ramo alcançar 100 cm de altura, desponte com 70 cm e desponte com 50 cm. Em ambos os experimentos, o comprimento dos ramos produtivos não interferiu na qualidade dos frutos e na produção. Entretanto, no primeiro experimento, como o número de cachos deixados por planta foi muito alto, as plantas com ramos de 60 cm tiveram uma redução no acúmulo de amido no sistema radicular o que afetou a brotação de gemas e formação de cachos no ciclo seguinte. No segundo experimento, todos os tratamentos de desponte proporcionaram a mesma qualidade e produção, e por ter sido deixado uma quantidade de dois cachos por ramo, o acúmulo de amido no final do ciclo produtivo foi similar entre os tratamentos. / The vine cv. Niagara Rosada is the main table cultivar produced in the state of São Paulo, Brazil. This cultivar is rather conducted in the Vertically Shoot-Positioned by the low implantation cost and for allowing canopy manipulation through pruning. The structure of the canopy directly affects the development of the vine, modifying the leaf surface exposed to the solar radiation that is responsible for the accumulation of carbohydrates in the root system. The amount of reserve carbohydrates can directly influence the fertility of the buds, the vigor of the plant and the productivity of the next season. The aim of this work was to evaluate the effect of the leaf surface of cv. Niagara Rosada vines, conducted in the Vertically Shoot-Positioned with different lengths of productive branches, in the production and accumulation of reserve carbohydrates in the root system. Two experiments were carried out with grapevines conducted in a vineyard system, in the productive cycle of 2016 and 2017, in Piracicaba-SP. In the first experiment, after the branches reached 100 cm in height, the shoot was performed at heights of 80 and 60 cm. The second experiment was composed of five treatments: Top with 100 cm high, with 70 cm after the branch reach 100 cm high, with 50 cm after the branch reach 100 cm high, with 70 cm 50 cm. In both experiments, the length of productive branches did not interfere in fruit quality and yield. However, in the first experiment, as the number of bunches left per vines was very high, the vines with branches of 60 cm had a reduction in the starch accumulation in the root system, which affected the bud budding and the formation of bunches in the next season. In the second experiment, all the shoot treatments provided the same quality and production, and because a quantity of two bunches was left per branch, the starch accumulation at the end of the productive cycle was similar between the treatments.