PLoS ONE (Jan 2020)

Leaf water potential of coffee estimated by landsat-8 images.

  • Daniel Andrade Maciel,
  • Vânia Aparecida Silva,
  • Helena Maria Ramos Alves,
  • Margarete Marin Lordelo Volpato,
  • João Paulo Rodrigues Alves de Barbosa,
  • Vanessa Cristina Oliveira de Souza,
  • Meline Oliveira Santos,
  • Helbert Rezende de Oliveira Silveira,
  • Mayara Fontes Dantas,
  • Ana Flávia de Freitas,
  • Gladyston Rodrigues Carvalho,
  • Jacqueline Oliveira Dos Santos

DOI
https://doi.org/10.1371/journal.pone.0230013
Journal volume & issue
Vol. 15, no. 3
p. e0230013

Abstract

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Traditionally, water conditions of coffee areas are monitored by measuring the leaf water potential (ΨW) throughout a pressure pump. However, there is a demand for the development of technologies that can estimate large areas or regions. In this context, the objective of this study was to estimate the ΨW by surface reflectance values and vegetation indices obtained from the Landsat-8/OLI sensor in Minas Gerais-Brazil Several algorithms using OLI bands and vegetation indexes were evaluated and from the correlation analysis, a quadratic algorithm that uses the Normalized Difference Vegetation Index (NDVI) performed better, with a correlation coefficient (R2) of 0.82. Leave-One-Out Cross-Validation (LOOCV) was performed to validate the models and the best results were for NDVI quadratic algorithm, presenting a Mean Absolute Percentage Error (MAPE) of 27.09% and an R2 of 0.85. Subsequently, the NDVI quadratic algorithm was applied to Landsat-8 images, aiming to spatialize the ΨW estimated in a representative area of regional coffee planting between September 2014 to July 2015. From the proposed algorithm, it was possible to estimate ΨW from Landsat-8/OLI imagery, contributing to drought monitoring in the coffee area leading to cost reduction to the producers.