Late pruning and its carry-over effects


The aim of this project was to determine if delayed pruning can be used as a tool to delay maturity. The study also assessed the carry-over effects of repeated late pruning on phenology, yield, leaf area and berry composition.

Project layout:
A commercial vineyard site in Barossa was used. The trial was conducted over four consecutive seasons where the effects of three different times of pruning were compared to each other.
1.       Winter (Control)
2.       Budburst
3.       2-3 leaves emerged

Results
-          Where vines were pruned at 2-3 leaves emerged, total soluble solids in grapes reached 12 Baumé 7 days later than the control in the first three seasons. In the last season, with this treatment, 12 Baumé was reached 14 days later;
-          Vines pruned at budbreak reached maturity in-between the control and the 2-3 leaves emerged treatments;
-          Late pruning did not effect yield in three seasons, but increased yield in one season;
-          Leaf area index at harvest in the 2-3 leaves emerged treatment was greater than or similar to the control;
-          With late pruning, the start of anthocyanin accumulation shifted and anthocyanin concentration and the anthocyanin:sugar ratio increased in two seasons;
-          Carry-over effects on yield, phenology, leaf-area and berry traits were negligible.

Significance of the study
The changing climate shifts vine phenology, leads to earlier and shorter harvests and changes fruit traits relevant to wine style. Late pruning (at 2-3 leaves emerged) can be used as a tool to spread out harvest without negative effects on yield or berry traits.

Not open source

Image: Shutterstock

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