Pre-emergence strategies can be optimised by understanding the germination pattern of weeds in your field. Emerging weeds must come in to contact with the ‘layer’ of residual herbicide on the soil surface to be controlled. By understanding when the weeds germinate, and how long it will take for them to emerge we can more accurately apply herbicides to coincide with their emergence.
Several factors influence germination pattern, including soil conditions (i.e. moisture) as well as seed position and dormancy.
Cultivations alter the position of seed in the seedbank so understanding where seed is and how that relates to the time it takes for emergence can help to refine herbicide strategies:
- Where seed is left on the surface or within the main germination zone, factors such as dormancy of freshly shed seed and moisture availability, will determine the emergence pattern of the weeds. If seed remains in the germination zone and are likely to emerge in one rapid flush then a single application should deliver good control.
- If deeper cultivations have been employed seed position will play an important role in determining germination pattern. Take a look at our Cultivation Insight tool to understand your seedbank based on recent or planned cultivations.