May 2026 | Grapevine Improvement Programme

The Sauvignon Blanc 2.0 Programme (SB2) aims to create the world’s largest collection of new Sauvignon blanc clones and identify those with valuable traits – such as higher yield, disease resistance, frost tolerance, and improved water efficiency – to strengthen the resilience of the New Zealand industry.

Now that the breeding vineyard is established in Lincoln with over 8,000 unique vines in the ground, we are testing ways to speed up the process from early selection to commercial trials. During the 2025–2026 season, trials were carried out to assess different propagation methods for SB2 vines. The aim was to better understand which approaches are best suited to Marlborough conditions and how they might be applied at scale in commercial vineyards.

The trial compared two propagation methods. Top grafting was undertaken directly onto established vines in three commercial vineyards, and nursery grafting was completed using cuttings sent to a propagation facility. The plant material used in both trials had not been pre-selected for specific traits. Instead, cuttings were taken from older SB2.0 vines within the breeding vineyard, based on the availability of suitable budwood.

Top Grafting Performance Across Sites

Top grafting was completed by an independent contractor at three Marlborough vineyards, Indevin, Marisco and Loveblock, across December 2025 and January 2026. The existing vines had their head removed at grafting time, and two two-bud spurs were grafted near the cut site onto the existing scion.

Results varied significantly between vineyards. One vineyard had a success rate of 94 percent, while another returned a solid 77 percent. In contrast, one vineyard recorded only 11 percent success.

At the lowest performing site, a high proportion of vines initially reached budburst, but most shoots died soon afterwards, leaving only five vines that survived through the season, and even those showed limited growth. At the 77% site, early shoot loss was also observed; however, subsequent shoots developed and persisted, resulting in a significantly better overall outcome.

Environmental and post-grafting management factors appear to have played a major role in the differences observed between sites. Water availability was identified as a likely contributor to poor performance at the lowest performing site, particularly given the challenges of adjusting irrigation for a small number of vines within a larger block.

Vineyard practices also differed, including in how growers managed competing growth from the original scion. Some removed all existing growth, while others retained selected shoots to support vine recovery.

Notably, the presence of GLRaV-3 did not show a clear relationship with graft success. On one vineyard that was tested, only a small proportion of failed grafts were associated with infected vines, suggesting that other factors such as moisture, vine balance and post-grafting care were more significant drivers of outcomes.

Nursery Grafting Delivers Consistency

Cuttings collected from SB2 vines in the Lincoln breeding vineyard were also sent to Ormond Nurseries, where they were grafted onto 3309 rootstock under standard nursery conditions. Cuttings were taken from 199 plants in the oldest 10 rows of the vineyard, with the thickest cane material prioritised rather than any specific traits.

Most grafted vines successfully progressed through budburst, grew well throughout the season and are now ready for processing. While success rates varied between clones and were not fully quantified, the results demonstrate the relative reliability of nursery grafting as a propagation pathway, particularly when budwood is precious and limited.

Some grafted vines displayed unusual phenotypes, several of which align with characteristics already observed in the breeding vineyard. This reinforces the importance of ongoing phenotypic assessment as material is scaled up and deployed commercially.

Next steps

This trial shows that nursery grafting remains the most dependable method for establishing SB2.0 vines in Marlborough. We now have more than 1,000 nursery-grafted vines available at Ormond, and we are in discussion with programme participants about hosting these vines.

However, based on industry experience, top-grafted vines tend to produce a crop earlier than nursery-grafted vines, although it’s still too early to confirm that in the case of these vines. We plan to keep the surviving trial vines to measure their maturation and productivity in future seasons. A new top grafting trial will be undertaken this summer using an alternative technique, chip grafting, that involves grafting a single bud lower on the trunk, which may improve consistency. We are using the learnings from this trial to also develop new management guidelines to ensure future top-grafted vines are best set up for success.

As the SB2 programme moves towards larger-scale field trials, scaling up the plantings of new clones will require careful planning, particularly around ensuring adequate sources of mature budwood and designing trials that can transition into commercial deployment. Continued collaboration between researchers, nurseries and growers will be essential to ensure that the gains from improved plant material are realised in the vineyard.