Application of Multispectral Images to Monitor the Productive Cycle of Vines Fortified with Zinc

Abstract

In the context of an exponentially growing population and resource limitations, precision agriculture techniques can improve efficiency in the agricultural sector. This can be achieved by monitorization and quick detection of changes in crops, resulting in smart resource use, waste reduction and maximization of production. In a field located in Palmela (Portugal), three foliar sprays of ZnO and ZnSO4 were performed in Vitis vinifera variety Fernão Pires, for production of biofortified single-vine wine. Field characterization was performed with soil sampling and UAVs (with altimetric measurement sensors), synchronized by GPS. Vegetations indexes and characterization of drainage capacity and slopes were then interpolated with mineral content, monitored with X-ray Fluorescence analysis. Morphologically, the experimental parcel had a slight slope (maximum of 1.10 m) with irrigation and nutrient availability in soil requiring special attention (i.e., just one-third of the parcel had higher capacity to water drainage). NDVI values reflected better physiological values in the N–NE region. Zinc increases in leaves were directly proportional with the applied concentrations in vines sprayed with ZnSO4 and ZnO; the concentration of 60% (900 g ha−1) revealed a greater vigor. In conclusion, the use of smart farm techniques and their crossing with analytical procedures allows the characterization and monitoring of vines, and a higher potential for optimization of wine production.