Macadamia is Australia’s most successful indigenous agricultural commodity. Although initial development through breeding and agronomic research was carried out in Hawaii at the Hawaii Agricultural Experiment Station (HAES) during the 20th century, this work has been furthered in Australia.
New varieties were developed in Hawaii, tested in previous regional variety trials and planted widely over the past 40 years in the then-fledgling Australian industry with varying success. Local macadamia breeding programmes were also developing and releasing varieties.
Variable performance of these Hawaiian varieties in Australia led to the establishment of the National Macadamia Breeding Programme.
From the first generation of macadamia seedlings 20 genotypes were selected to be included in Regional Variety Trials Series 3 along with five standard varieties (HAES 741, HAES 344, HAES 816, HAES 246 and A16). These genotypes were planted and tested in locations in QLD (Mackay, Emerald, three sites in Bundaberg, and Childers) and NSW (Alstonville, McLean’s Ridges and Macksville) for nine years.
Information on yield, nut and tree characteristics and kernel performance was collected and, using sophisticated genetic analysis, developed recommendations to the Australian macadamia industry. The different genotypes were grafted onto two rootstocks, H2 seedling and Beaumont cuttings, in a number of the blocks to test influence on yield and tree performance in different environments.
There was no consistent rootstock x scion (budwood) interaction meaning that in some locations, some traits, in different years showed some significant rootstock effect. For further details about the rootstock results in different soil types and regions, please review the final report.