Plant growth regulators in broad acre crops

Take home messages:

• PGRs are generally accepted to reduce plant height in grain cereals when applied at the appropriate stage of development; improvement in grain yield tends to be inconsistent

• A survey of 142 Australian agronomists found that only 20% recommend the use of PGRs in crop management of wheat, mainly due to improved lodging resistance followed by height reduction and improved yield

• Reasons why agronomists don’t recommend PGR use in the crops they manage were because they were ‘not needed’ or unsuited to their region

• Application of PGR with no change in yield from e.g. a 2.38 Mha area (representing 70% of the HRZ) would lead to a cost of around $70M. In contrast, there would be a net benefit of around $35M and $138M for a 5 and 10% change in grain yield in the HRZ.