To assess the value of PGRs with delayed harvest in HRZ regions for its effect on grain yield losses due to harvest timing, lodging, head loss and brackling.

• There was no significant interaction between PGR management, harvest date and variety. However, when harvested on-time, a single Moddus Evo spray was lower yielding compared to the untreated management but when harvest was delayed by almost a month, the single spray became significantly higher yielding than the split Moddus Evo management.
• Cyclops produced a yield of 4.74 t/ha which was significantly higher than Leabrook 4.31 t/ha, when averaged across all treatments in the trial.
• Leabrook was shown to be more prone to head loss when harvest is delayed and no PGR intervention used, however this did not translate into significant differences in final grain yield.
• The delayed harvest date did produce a significantly higher yield but did also create higher levels of lodging and brackling in both cultivars.
• In Cyclops, the shorter variety, the untreated control yielded the highest in both the on time and delayed harvest, with the use of PGR’s reducing yield. The inverse in true for Leabrook, with the application of some PGR’s increasing yield when compared to the control.

Trial design: Factorial (PGR x Harvest Date x Variety)

Rotation position: 1st Cereal after canola
Soil type: Forest gravel loam