Application of multiple spectral systems for the tree disease detection: A review

Abstract Tree diseases endanger forestry and fruit tree plantations seriously worldwide in the past decades, leading to significant economic losses for the agricultural production sector. Rapid and accurate detection of tree diseases is crucial in tree protection. Despite molecular biological detection methods have prominent specificity, they are time-consuming and laborious, and are not suitable for large-scale detection of tree diseases. Spectroscopy with nondestructive, rapid, and high throughput characteristics has been applied to plant disease detection. Spectral detection systems are divided into three categories according to the spectrometer's carrying platform: portable hand-held spectrometer, airborne vehicle-mounted spectrometer, and large laboratory spectrometer. This review summarized three main spectral detection systems and their advantages and disadvantages in detecting various diseases of forestry and fruit trees: including detection of the single disease, multiple stress, and early disease using Visible/near-infrared, Raman, and hyperspectral imaging. Finally, spectroscopy detection technology applications of challenges were summarized, highlighting future trends.