Spectral discrimination between Vitis vinifera and labrusca by spectroradiometric techniques

Abstract

Context and purpose of the study. Brazil is one of the few countries where vineyards of Vitis labrusca and Vitis vinifera coexist in the same geographical spaces, due to complex processes of territorial occupation by successive waves of European settlers. This situation presently leads to difficulties in the monitoring of grape and wine production, a necessary task to enforce regulations on wine quality. As an alternative to vineyard inventories informed by farmers, detection and discrimination of both Vitis species can be performed by Remote and Proximal Sensing techniques.

Material and Methods. Spectroradiometry was performed on living leaves of plants of Vitis vinifera and labrusca. Vineyards were separated by 200 meters to minimize confusion effects from environmental factors. Resulting reflectance spectra were analyzed by PCA and other statistical techniques, looking for wavelengths where both species can be discriminated.

Results. Spectral traits typical of each species are mainly located at visible and near-infrared wavelengths. Accuracies as high as 85% in discrimination were attained, characterizing these techniques as a potentially useful tool to vineyard monitoring.