Physiological and morphological responses of grafted and nongrafted Italia grapevines to different annual shoot (Cane) positioning systems

Abstract

Grapevines require timely and proper grafting, pruning, training, topping, pinching, girdling, and thinning techniques, even under optimal growing conditions. Accurate training and annual shoot positioning are particularly important for viticulture under protected cultivation, which is one of the most effective methods for sustainable grape production amid environmental stressors. A comparative study was conducted on vertical and horizontal cane positioning systems, focusing on the physiological and developmental responses of grafted and non-grafted Italia grapevines. The results indicated that bud burst percentages were higher in the vertical annual shoot positioning system compared to the horizontal type, with variations depending on the rootstock effects. The number of clusters per summer shoot was significantly influenced by the annual shoot positioning, with higher values observed in the vertical system. Pruning residue weight showed similar trends to the cluster number, except in non-grafted vines. Conversely, stomatal conductance was higher in the horizontal annual shoot positioning system than in the vertical type. In summary, annual shoot positioning systems significantly modulate the physiology and development of Italia grapevines, with effects varying based on rootstock use.