Use of non-invasive RGB imaging to assess the canopy status in organic viticulture
Keywords:Image analysis, leaf exposure, cluster exposure, canopy gaps, porosity, soil management
In organic viticulture, canopy features such as leaf area, canopy porosity and fruit exposure are critical due their impact on fungal disease incidence and grape composition. An adequate and accurate assessment of the canopy status is the first step towards appropriate and effective grapevine canopy management, therefore an easy, non-invasive, robust method to evaluate the main features of a grapevine canopy is needed. In this work a protocol for canopy status assessment based on non-invasive RGB imaging is presented and used to ascertain differences in the canopy status of grapevines grown under different degraded and non-degraded soil conditions. RGB images were processed using a classification algorithm based on the Mahalanobis distance, and then the pixels were classified in four classes: clusters, leaves, gaps and shoots. Overall, higher leaf exposure was observed in vines grown in non-degraded soil while the highest percent of gaps or canopy porosity corresponded to vines of the two cover crop treatments.
AUSTIN, C.N., GOVE, G.G., MEYERS, J.M., WILCOX W. F. (2011) Powdery mildew severity as a function of canopy density: Associated impacts on sunlight penetration and spray coverage. American Journal of Enology and Viticulture 62, 23-31
DIAGO, M.P., CORREA, C., MILLÁN, B., BARREIRO, P., VALERO, C., TARDAGUILA, J. (2012) Grapevine's yield and leaf area estimation using supervised classification methodology on RGB images taken under field conditions. Sensors 12, 16988-17006.
DIAGO, M.P., KRASNOW, M., BUBOLA, M., MILLAN, B., J. TARDAGUILA. (2016) Assessment of vineyard canopy porosity using machine vision. American Journal of Enology and Viticulture 67, 229-238.
HILL, G. N., BERESFORD, R.M., WOOD, P.N., KIM, K.S., WRIGHT, P. J. (2011) Image-assisted gap estimation, a simple method for measuring grapevine leaf canopy density. Crop Science 51, 2801-2808.
MAHALANOBIS, P.C. (1936). On the generalised distance in statistics. In: Proc. Of the National Institute of Science of India 12, 49-55.
PALLIOTTI, A., SILVESTRONI, O. (2004). Ecofisiologia applicata alla vite. In Viticoltura ed Enologia Biologica. E Cozzolino (ed.), pp. 41-88. Edagricole, Bologna, Italy
SMART R.E. (1987) Influence of light on composition and quality of grapes. Acta Horticulturae 206, 37-48.
SMART, R.E., ROBINSON. M. (1991) Sunlight Into Wine: A Handbook for Winegrape Canopy Management. Winetitles, Adelaide, Australia
TARDAGUILA, J., MARTINEZ DE TODA, F., PONI, S., DIAGO, M.P. (2010) Impact of early leaf removal on yield and fruit and wine composition of Vitis vinifera L. Graciano and Carignan. Effects of timing of manual and mechanical early defoliation on the aroma of Vitis vinifera (L.) Tempranillo wine. American Journal of Enology and Viticulture 61, 372-381.
How to Cite
Copyright (c) 2018 JAVIER TARDAGUILA
Copyrights and publishing rights of all the texts on this journal belong to the respective authors without restrictions.
This journal is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License (full legal code).
See also our Open Access Policy.