Key Points
- This project investigated the performance of weed control and herbicide options in maize crops sown at different times.
- Although early sown maize has higher yield potential, under high weed pressure where herbicides are less able to control weeds prior to canopy closure, this potential may not be realised.
- When planting early, a post emergence herbicide will often be required to achieve adequate weed control.
- It is important to operate a stale seed bed in paddocks with known high weed seed banks.
- Pre emergence herbicides should be applied to soil with good tilth and adequate moisture (or when rainfall is likely). Timing is critical for effective post emergence weed control – apply when soil is still visible between weeds and according to label instructions.
- Weeds that are no longer controlled at label rates by the same herbicide may be developing herbicide resistance. Rotate herbicides of different modes of action to avoid weeds developing herbicide resistance.