Photosynthetic pigments are essential for plant development. Quantifying these pigments in great extensions of agricultural crops is an important objective in remote sensing for agricultural purposes. This information can be used to produce a more accurate estimation of the physiological state of the vegetation, for species discrimination and productivity estimation. The aim of the present study was to (a) evaluate the potential for estimating chlorophyll content of crop canopies, using narrow band spectral indexes, and (b) in this respect compare the performances of NDVI (a multispectral wide band index) and two narrow band vegetation indexes (R 750/700 and R 750/550 ). Experiments were carried out under greenhouse conditions whereby soybean [Glycine max (L.), Merril] was monitored with a high-resolution spectroradiometer (10 nm at 365-1,126 nm range) during the phenological cycle of the crop. Chlorophyll (a, b and total) contents were determined weekly in the laboratory. A statistical correlation analysis was performed between narrow band spectral indexes against chlorophyll content and r 2 coefficients near 0.84 were obtained. For NDVI r 2 was around 0.51. These analyses showed that R 750/700 and R 750/550 ratios are very useful indexes for chlorophyll determination and very effective compared with NDVI (one of the wide band indexes widely used). Thus, it can be stated that hyperspectral remote sensing has great potential for providing a reliable estimate of photosynthetic pigment content at the canopy level through evaluated indexes and other such indexes that might arise. Thus, further studies should be carried out for evaluating other indexes at the canopy level, both in the laboratory and under field conditions, using spectroradiometers and hyperspectral images, aimed at providing information for agricultural purposes. Key words: canopy chemistry, hyperspectral remote sensing, remote sensing in agriculture, spectroradiometry. Índices hiperespectrais de vegetação para a determinação do conteúdo de clorofila em dosséis de soja [Glycine max (L.) Merril]:Os pigmentos fotossintéticos são essenciais ao desenvolvimento das plantas e sua quantificação em grandes extensões de culturas agrícolas é uma das metas mais importantes do sensoriamento remoto aplicado à agricultura. Essa informação pode ser utilizada para determinar, mais precisamente, o estado fisiológico das plantas, discriminar as espécies plantadas e estimar a produtividade. O presente trabalho teve como objetivos: (a) avaliar o acerto da estimativa do conteúdo de clorofila em dosséis de culturas, usando índices espectrais de bandas estreitas, e (b) comparar os desempenhos do Índice de Vegetação Diferença Normalizada (NDVI) em relação a dois índices de bandas estreitas (R 750/700 e R 750/550 ). Desenvolveu-se um experimento em condições de casa de vegetação cuja cultura da soja [Glycine max (L.) Merril] foi monitorada, durante o seu ciclo fenológico, com um espectrorradiômetro de alta resolução espectral (10 nm no intervalo de 365 a 1.126 nm). Determi...
RESUMO:A cultura de uvas de mesa em São Paulo vem aumentando de importância, o que é flagrante pelos incrementos na área plantada verificados nos últimos anos. A demanda por tecnologia tem acompanhado esse crescimento, especialmente no que se refere a novas variedades que atendam tanto ao mercado externo, quanto ao interno, com uvas de alta qualidade. No programa de melhoramento para uvas de mesa no Instituto Agronômico, iniciado em 1943, praticamente nenhum estudo foi efetuado sobre os progenitores utilizados nos cruzamentos. Neste trabalho foram avaliados centenas de cruzamentos e as variedades envolvidas, bem como suas progênies e seu interrelacionamento genealógico. De acordo com os dados analisados e os parâmetros utilizados, foram considerados preferenciais num programa de cruzamento para uvas de mesa as seguintes variedades: 'Itália', 'Patrícia', 'Soraya', 'Cardinal', 'Roberta', 'Maria Rosa', 'Carolina', 'Moscatel de Hamburgo', 'Lígia', 'Angelina', 'Marília', 'Alphonse Lavallée', 'Traviú', 'Ezequiel', 'Grão Mogol', 'Yole', 'Geni', 'A Dona', 'Aurora', 'Piratininga', 'Maria', 'Iracema'. Descritores: videira, melhoramento da videira, progenitores, seleção FORTY EIGTHI YEARS OF GRAPE BREEDING IN SÃO PAULO, BRAZILABSTRACT: The importance of table grape cultivation in São Paulo State, Brazil, is increasing in the last years, which is demonstrated by its acreage increase. Demands for technology improvements have followed, specially in respect to the development of new cultivars that can produce high quality grapes for exportation or internal markets purposes. Since the beginning of the grape breeding program at the Instituto Agronômico de Campinas (IAC) in 1943, no study was carried out on the parents used in crossings. In this study, hundreds of crossings, parents, as well as resulting progenies and their genealogical (pedigree) relationship were evaluated. According to the analysed data and parameters used we may consider as preferential the following
Número total de dias e graus-dia acumulados no ciclo total das plantas, da poda à colheita (P/C), para os cultivares que se destacaram no grupo A (sem sementes).
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