Utilização de fotografia hemisférica na determinação do índice de área foliar de oliveiras jovens (Olea europaea L.) Use of hemispherical photography for plant area index determination in young olive trees (Olea europaea L.)

Abstract

O índice de área foliar (LAI) é um parâmetro essencial para a caracterização da estrutura das copas e consequentemente para a avaliação da vitalidade das plantas. Neste estudo compararam-se valores de LAI obtidos através de métodos directos destrutivos e através da análise de fotografia hemisférica, em oliveiras jovens das cultivares ‘Galega’ e ‘Cordovil de Serpa’, num olival da região de Moura. Os valores determinados por fotografia hemisférica subestimaram significativamente (PThe determination of leaf area index (LAI) is essential in the characterization of the canopy structure and plants vitality evaluation. In this study destructive measurements of LAI were compared with values obtained by hemispherical photography analysis, of young olive trees cv. Galega and cv. Cordovil de Serpa, in an olive orchard of Moura region. As the direct method is assumed to be the most correct for estimating LAI, this method served as reference for the performance of the indirect methods. In order to be able to use the indirect methods to determine the LAI in the future, regression equations have been calculated taking into consideration the results of the indirect and the direct methods. Our results suggest that this procedure is an alternative method suitable to LAI determination in young olive trees after specific calibration.