Current trends in the use of thermal imagery in assessing plant stresses: A review

Abstract

Plants are the most important source of nutrition for humans and animals. Consequently, the demand for food keeps increasing over time. However, plants constantly face challenges in their natural habitats, such as biotic and abiotic stress. To address this problem, many genetic modifications have been performed to “establish” new plant varieties with high levels of resistance to stress. However, ethical and technical issues associated with genetic modifications gain more attention than their benefits. Thermal imaging is a non-destructive, non-contact, and sustainable method used for plant stress evaluation. Using thermal cameras, farmers can extract a plant’s spatial and temperature information. The objective of this study is to provide an overview of various thermal image–based methods to estimate biotic and abiotic stresses affecting a plant. This review shows that temperature can accurately describe the current status of the plant (stressed or unstressed). Using methods such as infrared indices, machine learning, and deep learning, the plant stress status can be determined. The evidence presented in various studies included in this review shows that thermal imaging is a practical and non-destructive technology that can be used to detect plant stresses.