Skip to main content
GrowersHelp your business growResearch reports, publications, fact sheets and more Macadamia second generation breeding and conservation (MC14000)
Ongoing project

Macadamia second generation breeding and conservation (MC14000)

Key research provider: The University of Queensland

What’s it all about?

This investment began in 2015 to progress genetic improvement for the Australia macadamia industry. It is working to produce new cultivars that will provide the industry an advantage over its international competitors.

Specifically, the project is evaluating 3555 seedling progeny already established, and aims to increase the second generation population size by 10,000.

Other significant activities of the project relate to the genetic control of husk spot disease and abnormal vertical growth, evaluating alternative breeding strategies, screening rootstocks for tree size control and productivity, and determining suitable pollinisers for elite selections.

ACT NOW

To learn more about the macadamia varieties produced by this investment, including information on how to access them, head to the Macadamia Innovation website.

The project continues to maintain and develop a host of trial sites. Here’s what the researchers have most recently reported…

  • 4, 5 and 6 year old trees are being harvested at Bundaberg between March and August 2019, with nuts under evaluation for comparison. There are 2,862 trees planted in these trials consisting of 2,387 seedling progeny and 475 clonally propagated parents and standards.

  • Clonally propagated wild accessions have been studied at Tiaro in Queensland and Alstonville in NSW to look at variation of growth, floral and nut characteristics for 13 trees. Next steps for these trials are being planned.

  • Husk spot, caused by the fungus Pseudocercospora macadamiae, is one of the major fungal diseases of macadamia in Australia. It is estimated to cause around $8 million production loss primarily through immature nut dropping. A progeny field trial at Maroochy Research Facility was converted to a disease screening nursery for husk spot in 2017, and a second evaluation has now been carried out to identify genotypes with a level of resistance to the disease.

The researchers on this breeding program, now in its fourth year, have released economic performance modelling for four recent macadamia variety releases, comparing predicted performance with established industry varieties.

The 20-year forecasts compare both annual net cash flow and cumulative cash flow for the varieties based on performance data from Bundaberg and the Northern Rivers of NSW.

As expected, cultivars with higher nut-in-shell yields and high kernel recovery were predicted to provide long-term economic benefits. 

Progeny grower trials are continuing, with several growers continuing to support the breeding program.

ACT NOW

The project continues to maintain and develop a host of trial sites. Here’s what the researchers have most recently reported…

  • In late May, close to 600 seedling progeny trees were planted on a commercial orchard in Emerald, Queensland, as part of the project’s grower field trials. These seedlings add to the 2500 planted elsewhere on grower properties in Queensland during 2017, and will provide new selections for future industry testing.
  • The project is maintaining a screening nursery for husk spot. In late September last year, the plants were exposed to diseased husks – hung in each to provide inoculum for potential husk spot infection – and irrigation was applied to ensure high humidity for disease development. After initial analysis, the researchers report that there was no significant difference in disease incidence among the varieties, however the work will be repeated during the year with a larger number of plants.
  • There are germplasm field trials, featuring clonally propagated wild accessions, at Tiaro in Queensland and Alstonville in New South Wales. Observations are ongoing, with a large number of trees producing nuts this year, and a host selected for harvesting once a month from February to August.

There are ongoing trials to evaluate rootstocks – with 22 genotypes currently being assessed. These genotypes consist of high performing rootstock cultivars; elite cultivars with high breeding values for harvest index; cultivars with high yield efficiency; potential dwarf genotypes from the industry breeding program; and wild germplasm accessions.

The project continues to maintain and develop new trial sites.

There has been an ongoing precocity trial, planted in 2011 to examine the variation for precocity within the project’s elite breeding lines and existing cultivars. The project team has selected 38 elite seedlings from this trial, based on their high levels of kernel recovery and small tree size. These will be clonally propagated this year, for further assessment of yield and agronomic traits.

The trial site has now become a screening nursery for husk spot. In late September 2017, plants were exposed to disease inoculum, and irrigation was applied to ensure high humidity for disease development. Susceptibility or resistance to husk spot was then due to be evaluated during March.

Also this year, a new abnormal vertical growth (AVG) trial will be established on a grower property in Bundaberg, to look at the inheritance of AVG resistance.

Meanwhile, during 2017 there were more than 2500 seedling progeny trees were planted as part of grower field trials in Queensland at Childers, Pine Creek and Alloway, to provide new selections for future industry testing. A new site is set to be planted at Emerald this year.

Related levy funds
Details

This project is a strategic levy investment in the Hort Innovation Macadamia Fund