Research to Reality Menu

Quick action unmasks poppy threat

by Kathy Grube

Within three months of being called on to help investigate the cause of the mystery fungal disease and to stop its spread, TIA's plant pathologist assigned to the case Dr Jason Scott confirmed infected poppy seeds are a major cause of disease outbreaks.

TIA is working on a DNA test to detect the pathogen in seeds and is trialling new seed treatments to stop the spread of the disease into next season's crop.

With the industry fearing the new disease discovered last season had the potential to devastate the state's future crops, time is critical in developing these strategies.

During the spring last year, poppy growers across the state started noticing large swathes of poppy seedlings withering and dying in their paddocks.

Dr Scott started collecting samples of crops affected by the more aggressive disease outbreak once reports were made.

"The young plants looked like they were being attacked by a common fungal disease called downy mildew," Dr Scott said.

"However, the disease was not behaving like the normal downy mildew that just affects the leaves and which poppy growers had been managing successfully for years.

Whole plants were being killed and it was wiping out large crop areas - something we had never seen before

"It was more virulent. Whole plants were being killed and it was wiping out large crop areas – something we had never seen before.

"The disease was also not responding to normal control measures, with commonly used fungicides proving to be ineffective."

The mystery disease outbreak sparked an industry-wide response.

The association that represents the farmers who grow poppies, Poppy Growers Tasmania, brought together the state's three poppy processing companies, the Tasmanian Government and TIA to develop an action plan.

Poppy Growers Tasmania chief executive Keith Rice said the poppy industry was very important to Tasmania's farming sector and the state's economy as a whole.

"Any threat to the industry is of enormous concern and taken seriously," Mr Rice said.

"It has been very pleasing to see the poppy industry, growers, poppy companies and the State Government come together in such a co-operative and effective manner to address this new fungal disease.

"Growers are nervous and concerned with the advent of this serious fungal infection, yet remain upbeat and heartened by the fact we have TIA-renowned agricultural scientific research capabilities and scientists with specific expertise in this specialist discipline.

"We remain confident the TIA scientific research will deliver strong practical tools to manage this disease as we move swiftly towards the 2015-16 season and beyond."

Dr Scott and his plant pathologist colleague Dr Calum Wilson developed a research proposal to address the concerns of the industry and this was accepted during the course of these industry meetings.

"We knew it was too late to do anything about the current crop in the ground and that the best course of action was to focus on developing strategies to minimise damage to future crops," Dr Scott said.

"TIA was tasked with a special $320,000 two-year rapid response research project, jointly funded by the Tasmanian Government, all three poppy processing companies (Tasmanian Alkaloids, GlaxoSmithKline and TPI Enterprises) and Poppy Growers Tasmania.

"The goal is to find out the cause of these new symptoms, identify seed and soil-borne sources of the pathogen and to study the pathogen's movement within the plant.

"We are also studying how the disease is influenced by environmental conditions, how it infests seed, and are looking to develop management strategies to reduce future disease outbreaks and spread."

The disease has since been found to be caused by a new species of downy mildew only recently identified and described as a new species in Europe. It had not previously been recorded in Tasmania.

TIA's newly developed DNA test can identify this new downy mildew pathogen in poppy seeds, which prevents diseased seeds being planted for the next crop.

The team is also developing new seed treatments, including chemical, microwave and heat sterilisation.

The goal is to find out the cause of these new symptoms, identify seed and soil-borne sources of the pathogen and to study (its) movement

Once this initial phase has been completed, TIA's work will expand into evaluating the role of alternate pathogen sources, the environment and testing potential control treatments.

The ultimate goal of this research is to put in place management tools for growers that ensure the continued long-term sustainability of the Tasmanian poppy industry.

A world-leading industry

Tasmania is the world's largest producer of opium alkaloids for the pharmaceutical market.

The state's poppy growers are highly efficient at growing poppies, producing 48 per cent of the world's opium alkaloids from just 11 per cent of the world's poppy production area.

Since commercial plantings in 1966, poppies have been one of Tasmania's most important crops. It is also one of the state's major agricultural export earners and one of the larger employers in the state.

The industry is vertically integrated with all poppy growing and initial processing, as well as a significant proportion of manufacturing, done in Tasmania.

More virulent

Downy mildew, caused by Peronospora meconopsidis, is not a new disease for poppies in Tasmania.

It has caused localised brown spots on leaves and reduced crop yield for more than 20 years, but has been effectively controlled with fungicides.

However, the new form of the disease causes stunting of stems, flower heads and sometimes kills whole plants.

Both downy mildew symptom types have been recorded in European poppy crops for many years, but it had been thought one species of downy mildew was responsible.

In spring last year, the more virulent downy mildew symptoms were widespread in poppy crops and the Tasmanian Government, together with industry partners, flew Austrian fungal taxonomist Dr Hermann Voglmayr to Tasmania in late November to analyse the fungus that was affecting the state's crops.

Dr Voglmayr confirmed the more virulent form in Tasmanian crops was caused by a new species that he had described only months earlier.

The newly discovered P. somniferi also causes a "systemic infection", which means the disease infects the plant tissues and spreads within the plant via its vascular system.
As a result most fungicide sprays do not kill the fungus.

It also means the plant is infected very early at seedling stage and as a result this new mildew causes much more damage.

$100 million a year - Value (farm gate) - Crop area 25,000 hectares - 1000 Tasmanian growers