Avocado researchers, Dr Liz Dann (right) and UQ PhD student Merran Neil
Avocado researchers, Dr Liz Dann (right) and UQ PhD student Merran Neil
1 February 2012

Researchers at UQ’s Queensland Alliance for Food and Agriculture (QAAFI) have acted swiftly to ensure Australia’s next $180 million avocado crop won’t be crippled by a fungus.

The popular fruit is susceptible to several fungal diseases but a study by QAAFI plant pathologist Dr Liz Dann has isolated and identified a potentially devastating new avocado pathogen which causes severe root problems, particularly in young trees.

Already known to cause black rot in peanuts and collar rot of papaya, the pathogen Calonectria ilicicola had not previously been confirmed as an avocado pathogen.

“The use of clean planting material is the most critical step in successful prevention of black root rot disease, caused by Calonectria ilicicola, in avocado,” Dr Dann said.

“Sometimes nursery-grown trees look deceptively healthy, even to a plant scientist.

“It’s not until you take a close look at an avocado tree’s roots and test them for common pathogens that you can be reasonably confident a plant is disease free.

“The avocado industry has had a scheme in place to ensure clean (disease free) planting material for many years, and it has served the industry well.

“By confirming the pathogen status of Calonectria ilicicola with this research, the fungus can be added to the list of identified root pathogens.

“Routine testing will alert nursery producers and growers about its presence or absence,” she said.

On average, each Australian consumes nearly three kilograms of avocados annually. With an estimated 1000 commercial growers, the $180 million Australian avocado industry has doubled in the size in the past decade, currently producing an estimated 9 million (5.5 kg) trays or 49,500 tonnes from about 1.6 million trees (2009–10).

Queensland accounts for some 65% of total Australian avocado production and Australian consumers nationally spend an estimated $420 million a year on avocados and their associated food products.*

Dr Dann’s study was published in the British journal Plant Pathology. This project has been funded by HAL using the Avocado industry levy and matched funds from the Australian Government.

Media: Dr Liz Dann (07) 3255 4352, e.dann@uq.edu.au or QAAFI Communications (07) 3346 0553, 0417 425 510


Dr Elizabeth Dann is a Senior Research Fellow at the Queensland Alliance for Food and Agriculture. A plant pathologist based at the Ecosciences Precinct at Dutton Park, her research aims to increase the productivity and quality of tropical and sub-tropical crops through improved management of diseases.* Avocado statistics taken from “Australian Avocado Industry Strategic Plan 2011–2016”. www.industry.avocado.org.au