52 research outputs found

    Características morfofisiológicas de Coffea arabica L. em diferentes arranjos: Lições de abordagem de plantas virtuais tridimensionais

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    3D vegetative structural and functional models are useful in simulations of ecophysiological and biophysical processes. The main objective of this study was to model a 3D Coffea arabica L. structure. The specific aim was to use 3D mock-ups for analysis of vertical leaf and berry distribution and light interception in coffee crops cultivated in different planting densities and arrangements. The mock-ups were built after abstraction and codification by VPlants, based on morphological measurements (orthotropic shoot height and its number of internodes; positions of second to fourth branching order plagiotropics; internode number on first to fourth branching order plagiotropics number of leaf pairs), and several hypotheses. Mock-ups were visualized in PlantGLViewer, while Silhouette to Total Area Ratio (STAR), leaf area (LA) and berry distribution were processed in VegeSTAR. Planting arrangements influenced STAR when the plants were grown in a low density (6,000 plants ha-1). Plant density had a significant effect on the number of berries in square arrangements. The higher layers were occupied by first order foliage and few berries, allowing more light to pass to the lower canopy layers. Berries were abundant in the first and second order plagiotropic branches, in the highest and middle layers. Light distribution was more uniform than leaf area distribution, indicative of a disperse foliage and efficient space occupation. STAR correlated strongly with berry number, especially in the upper, less shaded canopy layers, where flower induction was the most intense.Os modelos vegetativos estruturais e funcionais em 3D mostram-se úteis na simulação de processos ecofisiológicos e biofísicos. O objetivo principal deste estudo foi modelar a estrutura 3D de Coffea arabica L.. Os objetivos específicos foram analisar as distribuições verticais de folhas e frutos e a interceptação de radiação de cafeeiros cultivados em diferentes arranjos e densidades. As reconstruções 3D (maquetes) foram obtidas após a abstração e codificação em VPlants, baseadas nas medições morfológicas (altura do tronco ortotrópico; número de entrenós do tronco; posição e comprimento de ramos primários plagiotrópicos; posições de ramos de segunda a quarta ordem; número de entrenós nos ramos plagiotrópicos primários a quaternários; número de pares de folhas) e diversas hipóteses. As maquetes foram visualizadas no PlantGLViewer, enquanto a Razão da Área Total da Silhueta (STAR), área foliar (LA) e a distribuição dos frutos foram processados no VegeSTAR. O arranjo de plantas afetou STAR quando cultivadas em baixa densidade. A densidade influenciou significativamente o número de frutos no arranjo quadrangular. O espaço das camadas superiores foi ocupado por folhagem da primeira ordem e por poucos frutos, permitindo maior transmissão de radiação para as camadas inferiores. Os frutos foram localizados em abundância nos plagiotrópicos de primeira e segunda ordem, nas camadas superiores e medianas. A distribuição de luz foi mais uniforme do que a da LA, o que indica uma folhagem dispersa com ocupação eficiente do espaço. Houve alta correlação entre número de frutos e STAR, especialmente em camadas superiores, menos sombreadas, onde a indução floral foi mais intensa

    Soybean Architecture Plants: From Solar Radiation Interception to Crop Protection

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    The soybean plant architecture in relation to better solar radiation interception and production gain is an aspect that requires a better understanding, since soybean is an important crop worldwide. The genetic traits, management and environmental conditions are points that further extend the range of issues on crop productivity. The light quality is measured by the red/far‐red (R/FR) ratio (R ∼ 660 nm, FR ∼ 730 nm). This affects the plant growth and morphological developments in different ways. The plant leaves change their angle during the day to better intercept radiation. This heliotropic movement and some computational models together have been used to enhance some agricultural practices. Soybean plant is dependent on the interaction between genotype and environment. Thus, the enhanced understanding in relation to photosynthetic activity, grain yield by light interception efficiency and culture protection managements in soybean are covered

    Software for interpolation of vegetative growth of yerba mate plants in 3D

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    O objetivo deste trabalho foi construir maquetes de plantas de erva-mate em vários estágios de desenvolvimento com o uso do programa InterpolMate, e de computar a fotossíntese a partir de estrutura interpolada. Maquetes de erva-mate foram construídas com o software VPlants para três estágios de crescimento. Foram consideradas plantas do sexo masculino e feminino, cultivadas em dois ambientes distintos: monocultura e sub-bosque. Para modelar a arquitetura dinâmica 3D, de plantas individuais de erva-mate, durante o período bienal de crescimento entre duas podas, foram utilizadas informações coletadas em 38 datas do desenvolvimento dos galhos. Os valores estimados a partir das maquetes, incluindo dimorfismo sexual e fotossíntese foliar, são muito próximos aos observados em campo. Contudo, essa semelhança foi limitada às reconstruções que incluíram unidades de crescimento de conjuntos de dados originais. A modelagem da dinâmica de crescimento possibilita estimativas de fotossíntese de plantas inteiras da erva-mate, o que é dificilmente mensurável no campo. O software InterpolMate é eficiente na construção de maquetes de erva-mate.The objective of this work was to build mock-ups of complete yerba mate plants in several stages of development, using the InterpolMate software, and to compute photosynthesis on the interpolated structure. The mock-ups of yerba-mate were first built in the VPlants software for three growth stages. Male and female plants grown in two contrasting environments (monoculture and forest understory) were considered. To model the dynamic 3D architecture of yerba-mate plants during the biennial growth interval between two subsequent prunings, data sets of branch development collected in 38 dates were used. The estimated values obtained from the mock-ups, including leaf photosynthesis and sexual dimorphism, are very close to those observed in the field. However, this similarity was limited to reconstructions that included growth units from original data sets. The modeling of growth dynamics enables the estimation of photosynthesis for the entire yerba mate plant, which is not easily measurable in the field. The InterpolMate software is efficient for building yerba mate mock-ups

    Environmental stress evaluation of Coffea arabica L. leaves from spectrophotometric fingerprints by PCA and OSC-PLS-DA

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    The effects of hydric stress and sunlight access conditions on metabolic compounds in coffee leaves were investigated utilizing statistical mixture design extractor solvents. PCA and OSC-PLS-DA chemometric methods were used to analyze UV-visible spectra of irrigated and non-irrigated Coffea arabica L. leaves from low (80 cm, light exposed) strata. The first latent variable of the OSC-PLS-DA score plot perfectly discriminated extracts of 34 calibration and 14 validation samples of irrigated and non-irrigated leaves. Higher spectral signals observed at the 410, 505, 535, 607 and 665 nm wavelengths are attributed to conjugate double bond pigments, mainly pheophytin a, indicating that non-irrigated conditions are more stressful than irrigated ones for this species. No significant difference was found for leaf sample extracts with varying light access conditions12842514257CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorCNPQ - Conselho Nacional de Desenvolvimento Científico e Tecnológicosem informaçãosem informaçãoThe authors acknowledge the financial support of CNPq, CAPES, INCT – Energia e Ambiente and Fundação Araucária as well as for the scholarships granted. The Agronomic Institute of Paraná (IAPAR) is thanked for supplying the coffee leaf samples used in this wor

    Chemometric analysis of UV characteristic profile and infrared fingerprint variations of coffea arabica green beans under different space management treatments

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    Ultraviolet characteristic profiles and infrared spectroscopic (FTIR) fingerprints of green bean extracts of Coffea arabica L., cv. IAPAR 59, cultivated in two planting patterns, rectangular and square, and at two different densities, 10,000 and 6,000 plants ha-1, identified as R10, R6, S10, and S6 were analyzed with principal component and hierarchical cluster analyses. A simplex centroid design for four solvents (ethanol, acetone, dichloromethane, hexane) was used for sample extraction. The largest chlorogenic acid (CGA) contents were found at the lower planting density. The dichloromethane extracts of the S10 treatment showed the highest levels of unsaponifiable lipids (cafestol and kahweol). The R6 treatment showed a slightly higher content of cafestol and kahweol. Cluster analysis of FTIR fingerprints confirmed that the CGA and caffeine levels differentiate the spatial arrangements. The FTIR fingerprints suggest that green beans from S6 and R10 were richer in lipids and the other two treatments had more sugars and proteins27712541263CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informaçãoSem informaçã

    Respostas heliotrópicas de cultivares de soja em três estádios fenológicos e dois regimes hídricos

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    The objectives of this work were to determine the heliotropic movements of the upper trifoliates for two soybean cultivars, BR 16 and Embrapa 48, during a daily cycle, in three phenological stages and two water regimes, and to estimate the impact of irrigation and daily leaflet movements on agronomic characteristics and grain yield. Heliotropic movements were studied in three phenological stages: V4–V6, V7–V10, and R5 in irrigated and non-irrigated plots. For each stage, the leaflet elevation and azimuth were measured hourly. Under a low (V4–V6 stage) and mid (V7–V10 stage) leaf area index (LAI) the diaheliotropism was slightly more frequent and intensive in non-irrigated than in irrigated plants, only at early morning and late afternoon hours. At R5 stage (high LAI) the paraheliotropism of superior trifoliates was predominant and more intensive in non-irrigated plants. The heliotropic movements are correlated to carbon gain, but not to environment (light intensity or temperature), for measurements at 11h. 'Embrapa 48' expresses greater paraheliotropism than 'BR 16' at high LAI, while 'BR 16' displays lower heliotropic plasticity under irrigation. In spite of significant heliotropic differences, genotype and water availability treatments did not influence the final grain yield.Os objetivos deste trabalho foram determinar o movimento heliotrópico dos trifólios superiores de duas cultivares de soja, BR 16 e Embrapa 48, durante o dia, em três estádios fenológicos e em dois regimes hídricos e determinar o impacto da irrigação e do movimento foliar diário nas características agronômicas e na produção de grãos. Movimentos heliotrópicos foram determinados a cada hora, em três estádios fenológicos: V4–V6, V7–V10 e R5, em parcelas irrigadas e não irrigadas. Para cada estágio, a elevação do folíolo e o azimute foram medidos por hora. Em índices de área foliar (IAF) baixo e médio (V4–V6 e V7–V10), o diaheliotropismo foi levemente mais intenso e frequente nas plantas sem irrigação do que nas irrigadas, e somente nas primeiras horas matinais e últimas horas da tarde. Em R5 (alto IAF), o paraheliotropismo dos trifólios superiores foi predominante e mais intenso em plantas não irrigadas. Os movimentos heliotrópicos se correlacionaram com o ganho de carbono mas não com o ambiente (intensidade de luz ou temperatura), para medidas às 11 horas. 'Embrapa 48' apresenta maior paraheliotropismo do que 'BR 16', em plantas com alto IAF enquanto 'BR 16' apresenta menor plasticidade nas respostas heliotrópicas nas parcelas irrigadas. Apesar de diferenças no heliotropismo, o genótipo e disponibilidade de água não influenciaram a produção de grãos

    Biomass and leaf acclimations to ultraviolet solar radiation in juvenile plants of Coffea arabica and C. Canephora

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    E-26/202.323/2017 E-26/202.759/2018 E-26/210.309/2018 E-26/210.037/2020 PV 312959/2019-2 PQ 300996/2016 PVS 00583/20 UID/04129/2020 Funding Information: The authors acknowledge Funda??o Carlos Chagas de Apoio ? Pesquisa do Estado do Rio de Janeiro (FAPERJ) (Grants E-26/202.323/2017, WPR; E-26/202.759/2018, E-26/210.309/2018 and E-26/210.037/2020, EC), CNPq (awarded the fellowships: PV 312959/2019-2, MR; PQ 300996/2016, EC), and PVS 00583/20, EC FAPEMA (Funda??o de Amparo ? Pesquisa e ao Desenvolvimento Cient?fico e Tecnol?gico do Maranh?o), all from Brazil. Support from Funda??o para a Ci?ncia e a Tecnologia I.P., Portugal, to J.C.R. through the units UID/04129/2020 (CEF) and UIDP/04035/2020 (GeoBioTec) is also greatly acknowledged. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Despite the negative impacts of increased ultraviolet radiation intensity on plants, these organisms continue to grow and produce under the increased environmental UV levels. We hypothe-sized that ambient UV intensity can generate acclimations in plant growth, leaf morphology, and photochemical functioning in modern genotypes of Coffea arabica and C. canephora. Coffee plants were cultivated for ca. six months in a mini greenhouse under either near ambient (UVam) or reduced (UVre) ultraviolet regimes. At the plant scale, C. canephora was substantially more impacted by UVam when compared to C. arabica, investing more carbon in all juvenile plant components than under UVre. When subjected to UVam, both species showed anatomic adjustments at the leaf scale, such as increases in stomatal density in C. canephora, at the abaxial and adaxial cuticles in both species, and abaxial epidermal thickening in C. arabica, although without apparent impact on the thickness of palisade and spongy parenchyma. Surprisingly, C. arabica showed more efficient energy dissipation mechanism under UVam than C. canephora. UVam promoted elevated protective carotenoid content and a greater use of energy through photochemistry in both species, as reflected in the photochemical quenching increases. This was associated with an altered chlorophyll a/b ratio (significantly only in C. arabica) that likely promoted a greater capability to light energy capture. Therefore, UV levels promoted different modifications between the two Coffea sp. regarding plant biomass production and leaf morphology, including a few photochemical differences between species, suggesting that modifications at plant and leaf scale acted as an acclimation response to actual UV intensity.publishersversionpublishe

    Modulation of the yerba-mate metamer production phenology by the cultivation system and the climatic factors

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    International audienceIn rhythmic tree growth, the alternation between growth and resting phases can be either periodic or irregular, depending on climatic and endogenous factors. The aim of this study was to analyze the growth pattern of yerba-mate, a subtropical South American tree with monopodial and rhythmic growth, over a two-year period. Metamer emission rate of selected axes was followed during two years after a severe pruning in two cultivation systems contrasting for light conditions, agroforestry system and monoculture. A new longitudinal data modeling approach relying on hidden semi Markov chains to identify growth and resting phases and multiple change-point models to relate these phases to climatic factors was used. Despite large variability among individuals, two growth phases separated by a resting phase were most often identified within each year. Contrasting situations regarding the modulation of the polycyclism were observed between the two years and cultivated systems: in the first year of growth, the pattern consisted of a single long growth phase in vigorous individuals and the cultivation system had a major effect, likely due to the induced light environment; in the second year, some individuals did not grow during the second autumn phase likely due to the drought during the warm season. The observed differences in growth patterns between years and cultivation systems were interpreted with respect to ontogenetic and climatic effects, in interaction with endogenous factors resulting from plant reproductive phenology. This study introduces a new longitudinal data analysis approach for investigating the phenology of perennial plants over long follow-up periods, at time scale intermediate between days and years
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