The significance of scion x rootstock interactions

by | Sep 30, 2019 | Winetech Scan

In this study, researchers wanted to determine how consistently rootstocks affect the growth and fruit composition of scion varieties and identify scion x rootstock interactions.

PROJECT LAYOUT:

  • Drip-irrigated, spur-pruned Chardonnay, Cabernet-Sauvignon and Shiraz, grafted on seven rootstocks, in a hot-climate, was assessed over five seasons from 2013 to 2017.
  • The study was conducted with mature vines, established in 2006, as a randomised block design with five replicates.
  • Rootstocks included Ramsey, 1103 Paulsen and 140 Ruggeri and four promising selections from the CSIRO rootstock development programme.
  • Vines were trained as quadrilateral cordons on a two-wire vertical trellis of height 1.8 m and 3.0 m row × 1.8 m vine spacing, and irrigated with 5.5–6.0 ML/ha of water each season.
  • Each variety was harvested at 25.0 °Brix.
  • Vine performance and fruit composition was evaluated.

RESULTS:

  • Despite identical management practices, there were large differences between scion varieties in key growth characteristics (yield, pruning weight and Ravaz Index) across rootstocks.
  • Effects of rootstock on growth characteristics were smaller than the effects of variety.
  • The effect of rootstock on bunch weight and berries per bunch was consistent across scions.
  • There were significant effects of both variety and rootstock on yield, number of bunches, bunch weight, berry weight (scion only), berries per bunch, pruning weight and the Ravaz Index (yield/pruning weight).
  • Significant effects of variety and rootstock on fruit composition, included pH, titratable acidity (scion only), malate, tartrate (scion only), yeast assimilable nitrogen (YAN); and for the red varieties, total anthocyanins (scion only) and phenolic substances (scion only).
  • Significant interactions between scion variety and rootstocks were found for yield, number of bunches, berry weight, pruning weight and Ravaz Index.
  • Significant scion × rootstock interactions were also found for pH and YAN.
  • For each variety, significant effects of rootstock on fruit composition were linked to growth characteristics. However, these relationships, based on correlation analyses, varied for each scion.

SIGNIFICANCE OF THE STUDY:

The study has shown that the performance of scion varieties, and to a lesser degree the fruit composition, is dependent on rootstock choice. The inherent vigour of the scion variety must be considered in rootstock selection. Furthermore, individual scion/rootstock combinations may require specific irrigation, pruning or canopy management to achieve vine balance and optimise fruit and wine composition.

REFERENCE:

Clingeleffer, P., Morales, N., Davis, H., & Smith, H. (2019). The significance of scion × rootstock interactions. OENO One53(2). https://doi.org/10.20870/oeno-one.2019.53.2.2438

This abstract has been reproduced from its original form as permitted by the Creative Commons license: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0). Minor changes were made to the headings and the abstract was shortened by omitting some text.

Image: rootstock x scion. (Image source: https://www.ao.wine/vine-propagation-for-new-vineyard-planting)

Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors