The Semi-Minimal-Pruned Hedge: A Novel Mechanized Grapevine Training System.

A novel grapevine training system, semi-minimal-pruned hedge (SMPH), designed for mechanized pruning and harvesting was established on Sangiovese. The system was derived from adult spur-pruned cordon (SPC) vines that were modified to form a mechanically pruned hedge. SMPH heights of 80 cm and 120 cm were compared to SPC from 2005 to 2008, with an average of 332 and 479 buds per meter of row on SMPH 80 and 120, respectively, compared to 18 count nodes per meter of row on the hand-pruned SPC. The hedged vines had a larger leaf area, greater leaf area/crop ratio, and 35 to 40% yield increase compared to SPC, but there were no differences in juice soluble solids, pH, and acidity across the treatments. Berry skin anthocyanins were higher in hedged vines, notably the SMPH 120. The SMPH had more numerous but less compact and smaller clusters free of botrytis compared to SPC. While SMPH 120 showed a tendency to alternate bearing, this effect was minimal in SMPH 80. Single-shoot growth measured in 2006 was lower in SMPH vines, and total seasonal canopy light interception was higher compared to SPC vines. SMPH single-leaf assimilation was similar to SPC vines. Mechanical harvesting of both SMPH treatments was successful. These findings suggest that the two SMPH systems warrant further commercial evaluation because of their positive response to mechanization, grape yield, and quality and low susceptibility to bunch rot.