Grapevine dormant pruning weight prediction using remotely sensed data

Abstract

Aerial image analysis was utilised to predict dormant pruning weights between two growing seasons. We utilised an existing in-row spacing trial in order to examine the relationship between dormant pruning weights and remotely sensed data. The experimental vineyard had a constant between-row spacing (2.44 m) and five different in-row spacings (0.91, 1.52, 2.13, 2.74 and 3.35 m) resulting in spatial variation in canopy volume and dormant pruning weights (kg/metre of row). It was shown that the ratio vegetation index (NIR/R) was linearly correlated with field-wide measurements of pruning weight density (dormant pruning weight per metre of canopy) for both the 1998 and 1999 growing seasons (r2= 0.68 and 0.88, respectively). Additionally, it was shown that the regression parameters remained consistent between the two growing seasons allowing for an inter-annual comparison such that the vegetation index vs canopy parameter relationship determined for the 1998 growing season was used to predict field-wide pruning weight densities in the 1999 growing season prior to harvest.