Wheat and barley frost trials at Kingsthorpe, near Toowoomba, indicate that balancing planting time and varietal selection remains the best way of minimising frost damage, at least for the present.

A Queensland Department of Primary Industries and Fisheries (DPI&F) plant physiologist Troy Frederiks said a Grains Research and Development Corporation-supported trial at Kingsthorpe was designed to compare the frost resistance of commercial wheat and barley varieties and experimental lines, and to observe the impact of canopy architecture on frost damage.

Mr Frederiks said the trial was part of a research effort to reduce the frost risk for winter cereals using frost resistant genotypes and refine existing solutions.

Mr Frederiks said frost resistant varieties were a possible long-term result of the research effort, but  no  experimental line had yet been found to be significantly more frost resistant than our commercial wheat and barley varieties, either in this trial or in at least five years of previous trials.

DPI&F researchers were widening the search and increasing the number of lines tested each year, he said.

“Varieties with just an extra 2 degrees of frost resistance would allow earlier flowering and increase yield potential, while maintaining an acceptable frost risk,” he said.

Mr Frederiks said the Kingsthorpe trial included selected synthetic hexaploid and conventional wheat and barley varieties from the International Wheat and Maize Improvement Centre (CIMMYT), and barley lines from the South Australian frost-screening program.

Speaking at a field day held at the Kingsthorpe site, Mr Frederiks said recent Western Australia research showed that wider row spacing on sandy soils had little influence on frost damage, although this could well be different for Queensland’s heat-holding black soils.

“While row spacing manipulation may reduce frost damage in Queensland and NSW, the impact on total yield is the major consideration.”

He said because of previous research findings, some farmers had successfully used the strategy of planting early to make the best use of soil moisture before the onset of high spring temperatures.

Mr Frederiks said the Kingsthorpe research was helped this season by an infrared camera that provided images of the pattern of freezing of wheat in the field.

The thermography equipment had measured temperatures as low as minus 13 degrees in plant canopies at the trial site,  he said.

Visiting specialist Professor Mick Fuller, of The University of Plymouth, in the United Kingdom, brought the camera to Australia, with financial support from the University of Southern Queensland, the DPI&F and GRDC.