With a hull that acts as a blanket to protect grains and other protective anatomical structures, oats offer an alternative cereal option in frost-prone areas.

InterGrain national oat breeder Dr Allan Rattey addresses a field day near Highbury, WA, in September 2024. Photos: Supplied

With a natural edge, timely sown oats could be an option for reducing frost’s impact on a cropping program in frost-prone areas.

Western Australian Department of Primary Industries and Regional Development (DPIRD) research supported by GRDC has shown oats’ tolerance to frost is better than wheat and even barley. This aligns with international findings.

InterGrain national oat breeder Dr Allan Rattey says that while oats have an advantage, no cereal – wheat, barley or oats – is frost resistant if temperatures are cold enough.

Oats’ improved frost tolerance over other cereals is believed to lie in differences in floret anatomy. In oats, they are wrapped in protective glumes and hang downwards. Oat grains also have a hull that effectively acts as a blanket.

Balancing act

These specialised structures help in frosty conditions, but can, conversely, create challenges when oats experience excessive heat or drought.

“Oats have got better frost tolerance, but they’re inferior for heat and drought tolerance,” Dr Rattey says.

Dr Rattey says this played out in mid-September last year (2024) in the Wagga Wagga area, where huge frost losses were reported in wheat and barley.

The damage – which can include aborted seed, florets and pollen, and pinched grain – followed six days of minimum temperatures less than 1˚C, including one night at minus 3.4˚C. Losses in oats also occurred but were generally considered not as bad as wheat and barley.

Dr Rattey says research in wheat and barley has shown the time between flag leaf emergence and the end of flowering is the critical period. That is when all crops are most sensitive to frost, drought and heat.

“Depending on whether it’s a winter wheat, like DS Bennett, Illabo or EGA Wedgetail, it’s slightly different compared to a spring wheat like Scepter or Vixen,” he says.

“The same sort of things are understood for barley, but with oats we’ve got limited knowledge, to be honest.”

As a relatively minor crop compared with wheat and barley, oats have traditionally received less research attention, although there is a host of new projects in the pipeline.

Frost damaged Valiant CL Plus and Scepter wheat, near Goolgowi, NSW, which experienced several frost events in September 2024.

DS Pascal (left) and Longsword wheat, near Goolgowi, NSW, which experienced up to 80 per cent frost damage in September 2024.

Rethinking sowing dates, depths

On the heat side of the balance sheet, Dr Rattey believes the biggest lever growers can pull for avoiding spring heat and drought and maximising crop performance is timely sowing.

Oats can also be sown deeper than wheat and barley. Demonstrated by Processed Oat Partnership (POP) research in WA, it is due to the elongation of the mesocotyl and coleoptile. This allows oat seedlings to access subsoil moisture stored from summer rain, increasing emergence rates and biomass production.

“It fits oats into that system quite nicely of being able to sow it deeper than conventional wheat and barley and still make sure that you’re not going to get smashed by frost,” Dr Rattey says.

Breeding for yield, versatility

As one of the most flexible cereal crops, oats also offer a break from wheat and barley because of their different root pathotype.

Dual-purpose varieties include Goldie (launched in 2023) and Bannister (2012), which can be grown for grain or hay and potentially grazing. Koala, released in 2023 by the South Australian Research and Development Institute (SARDI) and Seednet, is adapted to longer seasons but may struggle in tight finishes. Minnie, launched last year by InterGrain, is a high-yielding short-medium stature mid to slow maturing milling oat. InterGrain has new breeding lines in the National Variety Trials and plans to release two or three more varieties in the next three to four years.

Research and opportunities

The GRDC National Grower Network (NGN) has supported a three-year project to evaluate deep sowing of oats in WA production systems.

Led by Facey Group, the project will explore sowing at different depths, their agronomic impacts and impact on pre-emergent chemistry, plus potential changes to machinery that might be needed.

The NGN is also investing in the development of milling oats agronomy packages for southern NSW and the Esperance Port Zone.

The projects will use field experiments to quantify the advantage milling oats have in those cropping systems to mitigate frost risks. They will also investigate the optimum time of sowing, sowing depth, sowing rates, disease tolerance and nutrition management.

Dr Rattey says oats are an emerging crop with “amazing health benefits”, and there is rising global demand from health-conscious consumers.

As research progresses and new varieties are released by GRDC’s National Oat Breeding Program, oats may well carve out a larger niche in Australian agriculture, particularly in frost-prone regions.

“We need to understand farming systems and the sowing window that’s appropriate for oats, especially on the east coast. That represents a big opportunity.”

InterGrain began transitioning SARDI’s oat breeding program into its commercially focused breeding programs in 2021.

This article appeared in GroundCover