- Minimal pruning is a vine management system developed in Australia and now widely used for wine grape production around the world. Porter Lombard started a minimal pruning trial in Cabernet Sauvignon following his visit to Australia in 1988. A replicated trial in Chardonnay was established at Woodhall vineyard in the winter of 1991-92. The minimally pruned vines in the Woodhall trial had been originally trained to an upright vertical training system with cane pruning. For conversion to a minimally pruned system, the foliage wires were removed, leaving a single wire at about 40 inches; the vines were not pruned that dormant season. Vines were skirted twice each season, once after bloom and once around veraison. Skirting consists of mechanically hedging shoots hanging down below the fruiting wire, either horizontally or, if needed, at an angle to remove a greater proportion of the canopy. The control vines were left on an upright vertical trellis and pruned to 24 nodes per vine. Vine spacing for both systems was 9 by 6 feet.
In previous seasons, the minimally pruned treatment had considerably more clusters per vine, smaller clusters, and greater yield than the control. Grape and wine composition did not appear to be greatly affected by minimally pruning. In 1993, incidence and severity of botrytis was reduced on minimally pruned vines, largely the result of smaller clusters.
Results for the 1994 season were similar in many ways to previous season's results (Table 1). The minimally pruned treatment had more than twice as many clusters as the control, clusters were about half the size of the control, and yield per vine was 37% greater than the control. Brix and titratable acidity were not significantly different, but pH was significantly higher on the minimally pruned treatment. There was no disease incidence in either treatment this year.