To assess the value of PGRs with delayed harvest in HRZ regions

ï‚· Buff achieved a grain yield of 6.29 t/ha significantly higher than RGT Planet at 5.85 t/ha when harvested on time.
ï‚· Harvest logistics and cultivar choice was the major factors influencing yield losses due to a delay in harvest. Buff suffered a 1.83t/ha yield penalty from delaying harvest by 3 weeks, and RGT Planet 1.07t/ha.
ï‚· Despite large yield losses to delaying harvest, plant growth regulators (PGRs) applied at all three timings did not offer any yield advantage in both cultivars whether harvested on time or when harvest was delayed. This is important because growers can have confidence in higher head loss risk areas that yield potential is unlikely to be compromised by PGR applications.
ï‚· Current recommendations to growers are to ensure timely harvest and to choose cultivars with improved head retention. Yields were lower than expected in 2020 and the additional benefits of PGR application for lodging and brackling control were not observed in this experiment.
ï‚· The use of PGRs for head loss control requires further development in 2021 but these and other center results have demonstrated there is little downside risk with the use of PGRs in the higher rainfall zone and a GS31 and later application could be combined with the most effective fungicide timings.

Rotation position: 1st cereal after canola, 2018 pasture, 2017 barley.
Soil type & management: Shallow duplex sand over gravel over clay. Clayed 2017, smudged
2019/20.