Precision viticulture: using on-board sensors to map vine variability and characterize vine trajectories

Precision viticulture consists in using ICT (Information and Communication Technology) to implement more specific and better targeted technical vine practices. With proxy-detection, precision viticulture mobilizes on-board sensors, computers, and GNSS positioning. Three sensors were embedded on a tractor and tested on a plot with three champagne grape varieties. This plot is located at the Plumecoq experimental vineyard (CIVC, Champagne, France). The first sensor is a pruning wood sensor (Physiocap) designed and developed by CIVC. Physiocap is used during dormancy season to characterize vine architecture by measuring shoot vigor, shoot number and biomass. The other two are growing season sensors. GreenSeeker Trimble provides a vegetative vine index by measuring foliage porosity. Multiplex Force-A characterizes vine metabolism through chlorophyll, anthocyanin, flavonol, and nitrogen leaf content. Data from these sensors define the physiological state of the vine at the time of measure. The sensors can also map spatial vine variability within a plot or between plots. To understand the vineyard as a whole, the combination of biomass indexes and leaf contents is interesting. In this case, there was some good correlation between the indexes and yield and must compounds such as nitrogen, acidity or sugar. By collecting sensor data at several key stages, it is possible to plot vine trajectories. Vine trajectory describes the physiological developments made by the vineyard according to its initial potential. It depends on annual climatic conditions and physical environment. Vine trajectories are useful to understand the effect of year and terroir.