Dr Jenny Davidson has called time on her career in pulse pathology after almost 30 years of service to the Australian grains industry.
She has witnessed enormous change in the South Australian pulse industry since her interest in research was sparked when she was just a child.
One notable change has been an upsurge in high-value lentil plantings and the retreat of field peas, a mainstay crop in the mid-1990s, to drier areas.
Dr Davidson says close to 150,000 hectares is now planted to lentils in SA, with many growers on the Yorke Peninsula deriving most of their income from the crop.
“Botrytis grey mould (BGM) was causing huge losses to lentils when I started my career,” Dr Davidson says.
“But now we have lentil varieties with resistance to BGM and management packages to keep the disease under control.”
Farm background
Dr Davidson grew up on a mixed farm near Strathalbyn, about 57 kilometres south-east of Adelaide. Back then, Dr David Sparrow, a barley breeder from the University of Adelaide, ran trials on her parents’ farm.
“I was fascinated with what he was doing and why, so when it came time to study, I went to the University of Adelaide to study agricultural science,” Dr Davidson says.
“In year four of my degree, we were allowed to specialise so, on the advice of Dr Sparrow, I chose plant breeding and plant pathology.”
Graduate work
Armed with her degree, Dr Davidson landed a short-term contract at the University of Adelaide, working with then faba bean breeder Dr Ron Knight.
Subsequently, she picked up a position with the then South Australian Department of Agriculture – now South Australian Research and Development Institute (SARDI) – working on barley leaf scald.
During this time, she met and married Fraser Davidson, who ran an irrigated property near Langhorne Creek, about 70km south-east of Adelaide.
Although Dr Davidson took a short break from research to start a family and raise the couple’s three daughters, her community involvement continued.
During that time, she was active in her local Landcare group, the Mt Lofty Southern Hills Soil Conservation Committee, and her local water resources committee.
“The Landcare work was particularly fascinating,” she says. “I enjoyed talking through the environmental issues growers were facing and helping to set up on-farm trials.”
Research continues
When the couple’s youngest daughter began school in 1995, Dr Davidson drove the 140km round trip each weekday from Langhorne Creek to Urrbrae to work as a pulse pathologist.
With support from growers through the South Australian Grain Industry Trust (SAGIT), her first project explored how to overcome Ascochyta blight in field peas.
At that time, growers were seeing grain yield declines in field peas but did not know why.
“Once people had grown field peas in a paddock for two or three times within the rotation, they noticed their grain yields dropped,” Dr Davidson says.
“Ascochyta blight was hammering yields, so we encouraged growers to widen their wheat/barley/field pea rotation to include canola because there was no varietal resistance to the disease and at that time fungicides were uneconomic in the low return crop.”
Industry collaboration
During her career, Dr Davidson collaborated extensively with breeders and agronomists to ensure whatever she suggested was practical to apply.
“Former SARDI pulse agronomist Dr Larn McMurray and I ran trials all over the state and working together meant growers were delivered a whole package because Larn had the agronomy knowledge and I had disease insights,” she says.
“The collaboration that characterised our relationship set a precedent for the way the SARDI pathology team works with agronomy and pre-breeding staff.”
Now, with the release of erect field pea varieties that do not “crawl all over the ground”, she says, Ascochyta blight has become less severe.
“And with the development of higher-yielding field pea varieties, there is added reason to use seed treatments and foliar fungicides to protect against Ascochyta and other diseases.”
Forecasting model
“We now also have a spore release forecasting model that pinpoints high-risk periods for infection, so people can choose whether or not to delay sowing to minimise infection.”
The forecasting model, called Blackspot Manager, was developed by former Western Australian Department of Primary Industries and Regional Development (DPIRD) scientist Dr Moin Salam, with GRDC and DPIRD co-investment.
During this time, Dr Davidson completed her master’s degree and PhD at the University of Adelaide. Her work involved validating the model in SA.
“We demonstrated that if Ascochyta blight is controlled at the seedling stage, yield losses were less likely.”
New pathogen
It was also through this research that Dr Davidson and her colleagues identified a new Ascochyta blight pathogen.
DNA tools are now used routinely to identify new pathogens, but back then pathogen detection focused on looking at the physical structure of the fruiting bodies.
“With this new pathogen, there had been a lot of confusion. While it looked like a range of other known pathogens, we knew it wasn’t those.”
When DNA sequencing became more widely available, Dr Davidson used the technology to check the genetic make-up of the new species, extensively comparing the new with the old.
“That’s when we realised we absolutely had something unique,” she says. “We named the pathogen Phoma koolunga, and it has subsequently been renamed to Ascochyta koolunga to reflect its correct genus.”
Disease management
While seed treatment is part of the integrated approach encouraged by pathologists when growing pulse crops, Dr Davidson says early advice centred around delaying sowing of field pea to avoid spore release periods.
However, with a trend towards shorter growing seasons, she says many people now see delayed sowing as a risky tactic.
“We now encourage the application of a seed dressing and to sow when ready,” she says. “If the Blackspot Manager modelling shows a high level of disease risk for a particular area, applying a foliar fungicide soon after emergence is recommended.”
To subscribe to the free blackspot SMS or email alert service (available for growers across WA, SA, Victoria and New South Wales), text ‘blackspot’, your name and the nearest weather station to
Extension efforts
Another way to hear about disease risks is through the Crop Watch SA alert.
Dr Davidson and former SARDI cereal pathologist Dr Hugh Wallwork – with rural journalist Jon Lamb managing the email distribution – started Crop Watch SA 15 years ago to disseminate timely disease alerts.
Over the years Crop Watch SA grew to more than 800 subscribers. Primary Industries and Regions SA (PIRSA) now disseminates the alert.
In 2014, approval was granted for Crop Watch SA to be disseminated via Twitter. At the time of writing, it had more than 830 followers.
Leader and mentor
In her tenure as SARDI’s principal research scientist in pathology for the past decade, Dr Davidson oversaw six laboratories and 20 staff.
During the past five years, she mentored SARDI pulse pathologist Sara Blake to take over her research on Ascochyta blight in lentils and faba beans, as part of a SARDI and GRDC co-investment.
“Sara’s work is looking at changes in the pathogen population and the subsequent loss of resistance in cultivars, in partnership with researchers at Curtin University who take care of the molecular side,” she says.
“Other aspects of her remit include providing plant pathology input into the University of Adelaide faba bean breeding program – working with Ascochyta blight and chocolate spot – and overseeing disease screening and surveillance through GRDC’s National Variety Trials.
“Sara has also taken the lead in presenting at GRDC Updates and the Hart Field Day. Going forward, growers and advisers are in a safe pair of hands.”
Science community
Aside from authoring and co-authoring some 50 scientific papers, Dr Davidson has enjoyed the collegiality of the Australian scientific community.
“Through GRDC, we’ve had a number of research projects where pulse pathologists, agronomists and pre-breeders from across Australia have collaborated and it has been a privilege to work with such a tight-knit group,” she says.
Internationally, Dr Davidson has authored and co-authored several books and chapters on Ascochyta in field peas, chickpeas and lentils.
She has also chaired the International Ascochyta Workshop Group, sharing her skills in epidemiology and management.
Science interest
In retirement, she has taken on a small role as SAGIT scientific officer, reviewing projects for funding and those already underway.
She is also shepherding several papers through the peer review process and acting as guest editor for a couple of scientific journals.
“It’s been a privilege to see just how much the pulse industry has expanded during my career,” she says. “I feel very fortunate to have had input into that.”