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Figure 3. Effect of conventional and ClearfieldÒ varieties with and without Spinnaker® herbicide on grain yield, biomass, harvest index and the percentage of frosted pods of lentils
Implications for commercial practice The outcomes from the 2019 trials again found instances where the varieties used in the ClearfieldÒ system were more affected by frost than the corresponding conventional varieties. However, these effects were not always consistent across varieties and in particular crops with ClearfieldÒ varieties of barley and lentils sometimes having less damage than the corresponding conventional options. A consistent outcome from the first two seasons of this project (2018-2019) have been that ClearfieldÒ varieties sown before the start of May have suffered the highest levels of frost damage which in turn negatively impacted grain yield. ClearfieldÒ barley options have been better suited to early sowing with Scope CL yields maximised when sown in mid-April and Spartacus CL yields maximised when sown from Anzac Day onwards.
Acknowledgements This project Investigating frost susceptibility on Clearfield® varieties treated with imidazolinone herbicide is funded by the South Australian Grain Industry Trust (SAGIT): MSF218. Thank you to Bulla Burra (Loxton) who hosted the trial site.