What was it all about?

Rootstocks are an important tool to reduce production risks associated with climate variability, salinity and soil-borne pests. Currently, the industry is reliant on rootstocks bred and selected overseas for conditions that may not be the same as those in Australia. 

Running from 2013 to 2017, this project set out to deliver new high-yielding, water-efficient and drought-tolerant rootstocks. It also investigated how high-density plantings and rootstock choices affected productivity under limited water supply. 

Researchers measured yield, berry weight, bunch weight, berries per bunch and total soluble sugars for comparison.

As a result of the work, four new rootstock genotypes were identified for release to industry, based on their performance compared with commercial rootstocks (Ramsey, 140 Ruggeri and 1103 Paulsen) when grafted with Carina, Sultana and Sunmuscat and managed with full and deficit irrigation treatments.

Studies also showed that different rootstocks will be required for different scion varieties to optimise their productivity. 

Results from the high-density trials also indicate potential yield benefits from adopting high planting densities with the low-medium vigour CSIRO rootstocks, compared to low planting densities with standard rootstocks.

The four new rootstocks will be released with Plant Breeders Rights protection through licensed nurseries. They have been included in a Plant Breeders Rights Comparator trial to establish distinctness, uniformity and stability. The establishment of mother plantings is being undertaken to ensure that adoption is not limited by the supply of propagation material.

In addition to further research on the new rootstocks, the team was working on fact sheets to facilitate adoption by growers, to be released when completed.