Evaluation of Water Potentials of Leafy Vegetables Using Hyperspectral Imaging

Abstract

To effectively and precisely manage crop production is important to meet increasing demands of high quality and safe agricultural products. In this study, evaluation of water stress in terms of water potentials of leafy vegetables using hyperspectral imaging technology was conducted for the future development of an agri-robotic system in greenhouses. The leafy vegetable Fengjing Pakchoi was cultivated under water stress treatments in a phytotron; both water potential and hyperspectral images were measured. The Modified Partial Least Squares Regression (MPLSR) with a correlation coefficient of 0.826 was successfully developed to determine the water potentials of leaves using hyperspectral imaging. Uneven distribution of water potentials on leaves was illustrated and discussed. Water stress which reflected irrigation status was visualized and compared by pseudocolor contour figures. This study had established a basis for the subsequent development of an agri-robotic system for automation and precision irrigation in greenhouses.