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| Picoli,Michelle Cristina Araujo; Duft,Daniel Garbellini; Machado,Pedro Gerber. |
| Abstract: The objective of this work was to evaluate the potential of several spectral indices, used on moderate resolution imaging spectroradiometer (Modis) images, in identifying drought events in sugarcane. Images of Terra and Aqua satellites were used to calculate the spectral indices, using visible (red), near infrared, and shortwave infrared bands, and eight indices were selected: NDVI, EVI2, GVMI, NDI6, NDI7, NDWI, SRWI, and MSI. The indices were calculated using images between October and April of the crop years 2007/08, 2008/09, 2009/10, and 2013/14. These indices were then correlated with the standardized precipitation-evapotranspiration index (SPEI), calculated for 1, 3, and 6 months. Four of them had significant correlations with SPEI: GVMI,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Saccharum officinarum; Drought stress; Image processing; Satellite imagery; SPEI; Warning systems. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2017001101063 |
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| Santos,Eduardo Alvarez; Sentelhas,Paulo Cesar; Pezzopane,José Eduardo Macedo; Angelocci,Luiz Roberto; Monteiro,José Eduardo Boffino Almeida. |
| Despite the importance of leaf wetness duration for plant disease epidemiology, there has been little attention paid to research on how its variability relates to different cropping situations. The objective of this study was to evaluate the spatial variability of leaf wetness duration (LWD) in three crops, comparing these measurements with turfgrass LWD, obtained in a standard weather station. LWD was measured by electronic sensors in three crops with different canopy structures and leaf area: cotton, coffee and banana. For the cotton crop, cylindrical sensors were deployed at the lower third and on the top of the canopy, facing southwest. For the coffee crop, flat plate sensors were installed in the lower third of the canopy facing northeast and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dew; Microclimate; Plant disease; Warning systems. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162008000700005 |
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