To evaluate the efficacy of pre-emergent herbicides applied post sowing on ryegrass control and crop safety in wheat with the aim of

a) increasing residual control,

b) improving in-row control and

c) preventing onset of trifluralin resistance.

• Preliminary results have shown that post sowing use of some pre-emergence herbicides can improve control of late emerging ryegrass and could be beneficial as a late salvage exercise where ryegrass has escaped earlier control.
• Although no damage to the wheat crop was observed, these treatments present a higher risk to crop safety, depending on soil type and rainfall after application.
• Post sowing use of these herbicides is currently off label & requires further investigation before registration can be granted.