If choosing to seed before spraying, weeds present will have a minimum five days — usually more — before the crop emerges, and these weeds can advance very quickly in good conditions. Growers who seed before spraying may choose to apply in the narrow post-seeding pre-emergence window.
If that window is missed, early in-crop weed management is essential to hold yield potential. Some yield potential is likely already lost to weeds by that time.
Remember: Weeds present before seeding are the most competitive weeds in the field. Since growers often miss the post-seeding, pre-emergence opportunity — due to the logistics of finding time to spray while seeding, and the chance that weather may not co-operate — the pre-seed window remains the better option.