Innovative Optical Sensors for Diagnosis, Mapping and Real-Time Management of Row Crops: The Use of Polyphenolics and Fluorescence.

FORCE-A’s Dualex^® leaf-clips and Multiplex^® proximal optical sensors give rapid and quantitative estimations of chlorophyll and polyphenolics of crops by measuring the fluorescence and absorption properties of these molecules. The in vivo and real-time assessments of these plant compounds allow us to define new indicators of crop nitrogen status, health and quality. The measurements of these indicators allow consultants and farmers to monitor the nitrogen status of row crops, for the management of the third nitrogen application on winter wheat, or to provide early estimation, at flowering, of future wheat grain quality, but also, to assess the canopy density of crops that can be used to adjust inputs of pesticides and fertilisers. We will illustrate these applications on row crops by showing results obtained both with the Dualex leaf-clip and an embedded Multiplex sensor, in wheat fields with variations in the nitrogen status, and in rapeseed fields with different seeding density. FORCE-A has also created recently a new data management tool. This system aims at acquisition, calculations, transformation and mapping of data. Thanks to these new optical sensors and associated models, the management of agricultural technical operations can be optimised and achieved for the whole field with a high spatial resolution, in real time or off-line.