It appears Macadamia is facing another disease threat after reaching a milestone $280 million harvest
Macadamia is part of the booming horticultural industry with an expected combined farmgate value $5.8 billion for the 2024-25 season.
The expected return from macadamia harvests each season is $280 million and increasing, and after solving significant disease management issues in an earlier project, a research team has turned its attention to a new threat.
Associate Professor Femi Akinsanmi from UQ’s Queensland Alliance for Agriculture and Food Innovation said the team was focused on emerging fungal diseases – husk rot, flower diseases and branch dieback.
“We solve one problem and then we realise that there are other priority diseases like these two major diseases of economic importance,” Dr Akinsanmi explains.
Husk rot affects the outer husk of the nut and can affect yield by causing the fruit to drop too early, while branch dieback appears on tree branches or trunks, which can kill a part or the entire tree.
Dr Akinsanmi said effective controls for the pathogens causing these diseases had not yet been established.
“We’re now investigating what is causing these diseases, what factors influence disease epidemics and how we can empower and support growers’ management decisions,” he added.
“We’re developing a forecasting tool to predict risk, building on our earlier work.”
The team is midway through a second five-year industry project, after earlier success in addressing husk spot disease and Phytophthora disease in macadamia, developing resources and building capacity for the industry.
Dr Akinsanmi said working in partnership with the industry has been rewarding.
“We generate new knowledge and discover new management options to control diseases sustainably.
“For example, husk spot disease can effectively be controlled using mechanical tree shakers.
“This disease has moved from being a major priority for the industry because it is well-understood and can be managed.
“Before this discovery, growers had to apply fungicides about six times a season to contain husk spot, but now they need a lot less.
“It has the double benefit of speeding up harvesting efficiency because macadamia is harvested on the ground.
“We also developed a soil health management package for Phytophthora that has reduced reliance on chemical applications and diagnostic tools for flower blight, so growers know what to expect and when the tree can become infected.
“That helps the industry to focus on what matters, producing the crop, while we safeguard their production and market assets.”
Macadamia grower and Hort Innovation Macadamia Strategic Investment Advisory Panel member Dr Chris Seale said macadamia disease research is very important to the industry.
“Dr Akinsanmi’s work has made a profound impact,” Dr Searle said.
“He has both reduced the amount of spraying for husk spot and improved Phytophthora management.
“It’s important to industry because it allows us reliability of supply, you have a more reliable income.
“In terms of the tree shaking, we also have an enormous time saving and a lot less spraying, which reduces the potential for community concern.
“It makes all sorts of things a lot easier.” This research is funded by Hort Innovation using the macadamia research and development levy and contributions from the Australian Government, The University of Queensland and the Department of Agriculture and Fisheries.
