How scientists are ripening Australia’s avocado stocks

By Professor Neena Mitter, Director, Centre for Horticultural Science, The Queensland Alliance for Agriculture and Food Innovation, The University of Queensland.

When I first moved to Australia in 2000, I had never tasted an avocado and to say my first experience was underwhelming would be an understatement. So it’s no small irony that I am now tasked with working with a team of scientists, farmers and nurseries to, as I have heard it described, ‘solve the world’s avocado shortage.

While this may seem unduly ambitious, the team at Queensland’s Alliance for Agriculture and Food Innovation (QAAFI), a research institute at the University of Queensland supported by the Queensland Government, is working to increase Australia’s avocado production. We are also looking to expand our presence in the global avocado export market through the use of new techniques to increase harvests and available varieties, while reducing growing times.

My wonderful team of dedicated researchers and PhD students received an Australian Research Council Grant, which funded our research for four years and more recently a three-year Advance Queensland Innovation Partnership Grant (around $1.2million) to investigate, research and trial methods for sustainable multiplication of avocado trees with the assistance of avocado growers and a nursery partner.

The result is a world first propagation technique which offers the potential to produce as many as 500 avocados plants from a single tree cutting. And what’s more, using a growth technique developed by my team at QAAFI, these trees can be made available to growers within eight to 10 months, as opposed to the 16-18 month timeframe by the traditional industry practice of multiplying a plant from a cutting.

Our research started five years ago when, after discussions with growers and industry partners, it became apparent that there was a huge shortage in avocado plant supplies.

There was then – and continues now – to be not enough avocado trees in nurseries in Australia to satiate demand. At the time, one of Australia’s biggest nurseries told me they have growers coming in wanting to order 100,000 plants for their orchard. The growers are told to come back in three years to pick up their order!

The math did not add up to be able to meet the orders because, simply put, for every new avocado tree you need a seed and a seed can only come from an existing avocado fruit. Historically, there had been no way to double, triple or quadruple production of plants without the required volume of seeds to do so. One can also get a an avocado plant by rooting a cutting from the tree, but as mentioned earlier it takes nearly 18 months to get a plant ready to go into the orchard.

After many years of research – and a few not so successful approaches – we have developed a method where we began taking 1mm from the tip of an avocado branch to the laboratory. We would give it the attention and love, the nutrition and the hormones that it needed and from that one cutting, we are now able to cultivate 500 new plants.

To date we have found this process to be successful with one of the variety used as the rootstock or base for the Hass avocado. We are now working on propagating more varieties and have had good success; however, more research is needed before we can take these to market.

An added bonus of this process is the plants propagated in the lab are disease-free. We can produce more than 10,000 plants in a 10sqm room.

We are planning on starting field trials in Queensland’s Lakeland, Tully, Bundaberg and additional trials to be held in NSW and Western Australia. The trials also give growers the opportunity to come and see for themselves what we are doing, ask questions and better understand the processes.

While I’m pleased to say our research will help secure our domestic supply – half of Australia’s avocado supply comes from Queensland farmers - it’s also our goal to use this to push Australia further as a leading exporter of premium avocadoes.

Currently Australia’s impact on global avocado trade, while increasing, still lags well behind other avocado producing countries.

A report released by industry body Avocados Australia in August 2017 shows, that despite some small fluctuations in production volumes in the past three years, the value of exports of Australian avocados has near-doubled in the same period from $6.4 million to $12.5 million.

The World Atlas lists Mexico as the world’s largest producer of avocados with 1.52 million metric tonnes annually.

And with Australia’s annual exports at $12.5 million, we are still a long way behind the world’s top exporters according to Worlds Top Exports with Mexico exporting $US2 billion worth of avocados in 2017. The Dominican Republic was 15th on the list with 2017 exports valued at $33.4 million.

At present, Australia only exports about 2 per cent of avocados grown here and we believe that our technology can help in increasing the export potential.

In fact, news of the progress we are making has already reached foreign shores with a number of growers and nurseries from across the globe contacting us to find out more about our research.

And from my first forgettable experience tasting avocados, my tastes have evolved to allow me to indulge frequently in avocados to the point where I have even developed my own Indian-inspired guacamole.