Comparison of trellises and pruning levels for Sultana vines in the Murray Valley

Abstract

Five trellising systems for irrigated sultana vines under conventional district spacing have been compared in a field trial at Mildura, Victoria. They were 'narrow T', 'narrow T, one foliage wire', 'narrow T, two foliage wires', 'narrow double T' and 'wide T'. For the first two years of the trial, pruning was to six 14-node canes for each vine, then for the next four years three levels of pruning were imposed on the trial as split-plot treatments-'severe'' (as before), 'medium' (averaging about eight 14-node canes) and 'light' (averaging about ten 14-node canes). There were no differences in yield due to the trellising treatments until differential pruning was introduced. Then there were significant differences in dried fruit yield due to trellising, regardless of pruning, in the two good harvests, and due to pruning in all four seasons. Overall the two best treatments were 'light' pruning with 'narrow T, two foliage wires' or with 'wide T', both yielding a quarter more than the conventional 'severe' pruning with 'narrow T'. The differences are seen as due to more bunches per vine with 'light' pruning, and to the ability of 'narrow T, two foliage wires' and of 'wide T' to support without crowding the greater number of bunches put down.