Frost ratings new tool to manage costly issue

Author: Natalie Lee | Date: 20 Feb 2015

Image of DAFWA researcher Dr Ben Biddulph

Preliminary frost susceptibility ratings for wheat and barley will be made available to Australian grain growers for the first time this year.

This paves the way for pre-emptive action to help them reduce frost risk when deciding which varieties to sow.

It is estimated frost costs the Australian grains industry about $360 million annually in direct and indirect yield losses, particularly affecting western and southern cropping regions.

Breeding new cereal varieties with improved frost tolerance is the ultimate solution to minimising the economic losses resulting from frost.

To address this, the Grains Research and Development Corporation (GRDC) established the National Frost Initiative in 2014.

This initiative takes a multi-discipline approach to frost mitigation that encompasses genetic, management and environmental solutions. It has brought together ongoing and new research projects focussed on frost.

One of the key projects in the initiative is the Australian National Frost Program (ANFP).

Through this project, researchers are collaborating across states to make headway in understanding variations in frost susceptibility in Australian wheat and barley varieties.

Successive GRDC-funded projects have enabled dedicated frost screening nurseries to be developed in Wickepin in WA, Loxton in South Australia and Narrabri in New South Wales.

At these sites, 72 lines of wheat and 48 barley varieties have now been assessed for susceptibility to reproductive frost damage in trials set up in 2012, 2013 and 2014.

Data from these trials has led to the development of the first wheat and barley variety frost susceptibility ratings, which will be available this year on the National Variety Trials (NVT) website.

Ratings do not take into account the frost risk associated with a particular variety’s flowering time given a certain sowing date, but refer to the relative susceptibility of varieties flowering at the same time.

Department of Agriculture and Food, Western Australia (DAFWA) frost researcher Ben Biddulph is leading the WA node of the ANFP and frost susceptibility ratings for wheat and barley in WA and will discuss how the ratings should be used at the 2015 Agribusiness Crop Updates.

He said a selection of the most commonly grown wheat and barley varieties in WA were compared at trial sites at Merredin and Wickepin, along with varieties that had been well characterised previously for frost susceptibility and other lines of particular interest to breeding companies.

Dr Biddulph said across three years of the WA trials, it was found that wheat and barley varieties did differ in susceptibility to reproductive frost damage during booting and flowering and no varieties were frost tolerant.

He said under severe frost (for example -4°C), or multiple minor frosts (several nights of -2º to -4ºC), all varieties tested were equally susceptible - resulting in up to 100 per cent sterility in flowering heads.

“Variation in reproductive frost susceptibility has not been linked to variation in susceptibility to stem frosts (as experienced in 2014 across Southern Australia), or to later frosts during grain filling,” he said.

Dr Biddulph said selecting an appropriate maturity for a particular sowing time was still a grower’s best option to limit frost damage.

He said the new reproductive frost ratings should be considered with regard to the relative time of sowing and flowering time prediction - and frost and heat risk - through tools such as Flower Power or Yield Prophet®.

“Continue to select varieties based on the best yield, maturity, agronomic and disease performance information from various sources, such as regional agronomy trials and NVT,” Mr Biddulph said.

“The preliminary frost susceptibility ratings can then help to fine-tune frost risk management tactics, based on current management of known varieties with a similar rating.”

GRDC is continuing to fund research in WA and nationally to further validate the relationship between compensation ability, reproductive frost damage and grain yield in existing and emerging wheat lines.

The 2015 WA Agribusiness Crop Updates will be held at Crown Perth on 24 - 25 February. For further event information contact the Grain Industry Association of WA office on 08 6262 2128.

More information on Regional Crop Updates 2015 is available

Useful resources:

GRDC Project Code UA00136, DAW00234, CSP00143, DAW00162, UA00114, UA00063, UA00100