2017 Giesco international meeting, paper conference presentation

Abstract

This report gives an account of Martin Moran's attendance at the GiESCO 2017 conference in Mendoza, Argentina, at which he presented earlier work (part of SAR 1304) on the use of late pruning to delay grape maturity and harvest.

Summary

Warming is shifting vine phenology, compressing harvests, and altering the balance of fruit traits relevant to wine. The aim is to test late pruning as a tool to delay maturity and to assess carry-over effects from repeated late pruning on phenology, yield components, dynamics of leaf area and berry traits of Shiraz grown in the Barossa Valley of Australia.

A trial was established in a commercial vineyard comparing three pruning times in July 2012: winter (control), budburst and 2-3 leaves emerged, during four consecutive seasons. Compared to controls, total soluble solids in berries of vines pruned at 2-3 leaves reached 12° Baumé seven days later in the first three seasons, and fourteen days later in the last season; the budburst treatment was intermediate between winter and 2-3 leaves. Yield was unchanged by late pruning in three seasons and increased in one. Leaf area index at harvest in 2-3 leaves was larger or similar than in controls. Late pruning shifted the onset of anthocyanin in relation to sugars and increased the anthocyanin to sugar ratio in two seasons.

Late pruning delayed maturity with neutral or positive effects for yield and berry traits. Carry-over effects on phenology, yield, leaf area and berry traits were negligible.