GRDC Frost Extension project

Summary

Small plot frost trial at Tim Zacher’s Tooligie. Extension materials distributed via newsletter and podcasts.

A trial site consisting of eight cereal varieties (Barley, Denison, Rockstar, Scepter, wheat mixture, Mace, LR Dual, Vixen) was sown near Tooligie in 2021.  This site aimed to demonstrate how cereal varieties with different flowering times and maturities are impacted by frost.

The 2021 Tooligie frost site experienced 38 possible frost events (<0°C) throughout the frost vulnerable stages of crop development (first node to grain fill). As a result, all varieties where damaged to some extent by frost.

Spartacus yielded the highest overall (1.84 t/ha), followed closely by the latest maturing wheat variety Denison (1.56 t/ha). Differences in the yield of the remaining varieties was not significant and ranged from Rockstar 0.62 t/ha to Vixen 0.27 t/ha.  The Tooligie environment in 2021 had a water limited yield potential of 3 t/ha.

These results confirm our current understanding, that barley is more physiologically tolerant to frost, and that slow maturing wheats help, but not eliminate, frost damage by developing later in the season.

Grain quality was affected in all varieties trialled at Tooligie. The test weights of Denison and Rockstar where below receival standards, and Spartacus was only able to achieve a receival classification of Feed 3.

Except for the awnless wheat variety LR Dual (3.9 t/ha), the remaining varieties in this trial produced biomass of around 6 t/ha. For farming systems equipped with machinery/infrastructure, grazing or hay production may have been more profitable than grain production.