APPLICATION OF PROXIMAL AND REMOTE SENSING ON PRECISION VITICULTURE IN SARDINIA (ITALY) - PRELIMINARY RESULTS

The colored grapes anthocyanins content is a useful tool to allow the decision support system in viticulture. The optical portable sensor Multiplex3® (FORCE-A, Paris, France) is able to screening the colored component of grapes with a rapid and non-destructive method. Such is based on the transmission of fruit chlorophyll fluorescence in accordance to anthocyanin contents of intact berry skin, therefore some indices that described this phenomenon are ANTH_RG (Anthocyanin excitation in Red-Green fluorescence) and FERARI (Fluorescence Excitation Ratio Anthocyanin Relative Index). The aim of this study is the calibration of FERARI and ANTH_RG indices in relation to total anthocyanins content (mg/100g skin), obtained by wet chemistry analysis. The trial was carried out in two Cagnulari vineyards in the Northern Sardinia (Alghero, Sennori). The ANTH_RG and FERARI indices were monitored in the fields, on bunches, during the 2015 season from veraison to harvest. The FERARI index show a good correlation with the anthocyanin concentration derived from spectrophotometric analysis in both samples (Alghero ?=0.69, Sennori ?=0.66), the equation obtained for this index is a logarithmic curve. The ANTH_RG index show a weak inverse correlation with the anthocyanins measured (Alghero ?=-0.24, Sennori ?=-0.23), and the curve that fit as better as possible the data is an exponential. In conclusion, in this first part of the research, we observed that FERARI index may provide decision supports for precision viticulture. Further studies are oriented to confirm this preliminary results.