This is a final research report from Hort Innovation’s historical archives. Please note that as these reports may date back as far as the 1990s, the content and recommendations within them may be superseded by more recent research.

What was it all about?

The Macadamia improvement and conservation program had a major impact on the management of genetic resources for the Australian industry. This project selected 20 candidate cultivars that were predicted to increase the profitability of the Australian industry by 30 per cent. A discounted cash flow model of macadamia production and processing had been developed and was used to identify selections with the suite of characteristics that had the greatest economic impact. Much of this gain were delivered to the grower, as the major trait influencing selection was yield, although selections were also on average, smaller trees, and have higher kernel recovery, percentage of whole kernels and kernel quality.

The field performance and commercial kernel quality were evaluated by a selection committee to identify any candidates that did not meet industry standards. Improved knowledge on the performance of different rootstocks in the nursery and early orchard production had prompted the adoption of ‘Beaumont’ as an alternative to ‘H2’ for propagation of the new selections for RVT testing. To support these decisions improved kernel assessment methods were developed that allowed selection to target kernel traits so that kernel quality could be maintained and improved in future selections. To assist in cultivar identification and protect the industries research investment a new suite of DNA markers were developed.

Further gains were anticipated since monitoring of the second series of crosses that were established across 12 sites over three growing regions to better sample the range of environmental variation for macadamia production had been maintained. The wild germplasm collections at Tairo and Alstonville were maintained to support the future incorporation of this material into the improvement program to deliver new cultivars with novel characteristics for transformational change to the industry.