Tasmanian claims top onion honour
Dean Metcalf has spent more than a quarter of a century studying onion related diseases in a passionate quest for results. He was presented with his award by Onions Australia Chairman Kees Versteeg and Assistant Minister for Agriculture and Water Resources Senator Anne Ruston at the completion of the Onion Australia conference in Melbourne last night.
It was just over 25 years ago that Dr Metcalf looked through a microscope and viewed a fungus killing another fungus, discovering that that it was Trichoderma – which led him to the idea that maybe the killer fungus could be used as a fungicide.
And that was the start of a lifelong passion in the horticulture industry.
Dr Metcalf, who originally comes from the Ovens Valley in North East Victoria, undertook a science degree at Roseworthy College in South Australia.
On returning to Victoria he found work in the Hop industry and was transferred to Tasmania. After a couple of years in that industry he went back to university, wanting to research the use of Trichoderma to control crop disease. The first opportunity he found was in the onion industry where he started to work on a biological control for onion white rot for his Honours project and got a PhD Scholarship sponsored by the Tasmanian onion industry to continue the work, which generated some very promising results.
1996/97 saw the worst season on record for the Tasmanian onion industry due to an epidemic of neck rot, which caused one-third of exported onions to decay in transit. Dr Metcalf got the job of working out what had gone wrong and assembling a management strategy, which has largely been successful though the disease has never completely gone away.
In 1999 Dr Metcalf moved back to Hobart to lead the Tasmanian Plant Disease Diagnostic lab where he helped farmers identify a very wide range of crop diseases and served as Quarantine Pathologist. He maintained his interest in onion diseases and biological control in the background.
In 2002 he started a business “Metcalf Biocontrol” in collaboration with a compost manufacturer. The first objective was to learn how to mass produce Trichoderma and further to multiply it using the natural heating cycle of compost and the process developed was successfully patented.
Dr Metcalf widened his biological control interests into grapes and over the next few years developed biological control agents for control of Botrytis in grapes .
He also developed products to control brown rot in stonefruit, as well as root rot in avocadoes and raspberries, husk spot in macadamias and onion white rot.
Dr Metcalf has continued his work on Botrytis neck rot of onions, including better understanding of detection in seed, fungicide control, infection process, factors affecting Botrytis during curing, negative effects of wetteners which enhance infection and most recently the epidemiology of Botrytis in the seed crop.
As the senior plant pathologist for the DPI in Tasmania from 1998-2011, he provided a significant contribution to identification and control options of diseases for various horticultural crops in Tasmania including neck rot and white rot in onions.
Another key aspect of Dr Metcalf’s involvement was in understanding the effect of various surfactants and wetters on the cuticle of the onion and the potential for the resulting damage to encourage diseases such as botrytis allii to penetrate the leaf surface and migrate to the neck of the onion causing neckrot. This very important piece of research helped focus attention on the practice of using surfactants in fungicide mixtures and the need to factor in the use of products that were not as destructive on the wax layer of the leaves.
Mr Versteeg said Dr Metcalf was one of the most experienced onion plant pathologists in Australia, if not the most experienced.
“Dean has been a member of the OA Executive since 2004, which relies on his scientific experience, and is an extremely worthy recipient of this year’s Reg Miller Award,” he said. “His work is respected by all in the Australian onion industry, and his dedication to our humble allium is almost unparalleled.”
For more information:
Lechelle Earl
Onions Australia CEO
Tel: +61 0458 11 11 26
Email: Lechelle@onionsaustralia.org.au
www.onionsaustralia.org.au