Monitoring of macro- and micronutrients in vine leaves by short-wave infrared hyperspectral imaging

Wine is a widely diffused beverage in the world and its production and quality are greatly influenced by the health conditions of the vine plants. The aim of the study was to investigate the possibility to monitor by Hyperspectral Imaging (HSI) the macronutrients (i.e., Ca, K, etc.) and micronutrients (i.e., Mn, Cu, Zn, etc.) variation in leaves sampled from different areas of a vineyard. The proposed approach is based on the acquisition by HSI in the Short-Wave Infrared Range (SWIR: 1000-2500 nm), of dried and milled vine leaves, followed by the implementation of a classification model based on Partial Least Square (PLS). Micro-X-Ray Fluorescence (micro-XRF) analyses were carried out on the same samples to correlate the SWIR spectral signatures with the detected chemical elements. Furthermore, HSI-based prediction maps, representative of the chemical elements distribution in samples were obtained. The achieved results are very promising, especially with reference to the possibility to adopt a fast strategy to monitor the macro- and micronutrients variation in the leaves directly in field, allowing to treat in real-time any nutritional deficiencies.