Pre-emergent herbicides are an important tool for weed control in dry and early sowing systems, but changing sowing conditions, machinery speeds and seed placement can influence both crop safety and herbicide performance. This project investigated how sowing speed, seed placement and seeding conditions affect crop establishment, herbicide injury and weed control, providing growers with practical guidance to reduce establishment risk while maintaining effective weed management.
Field trials conducted across South Australia evaluated a range of pre-emergent herbicides under different sowing conditions, helping growers better understand how machinery setup and sowing practices can influence crop safety and maximise herbicide performance.
Project description:
Building on previous SA Drought Hub research into dry and early sowing systems, this project investigated how seeding conditions and machinery operation influence the performance of pre-emergent herbicides in cereal crops. As growers increasingly adopt early sowing strategies, understanding the interaction between herbicides, soil conditions and seed placement has become critical for maintaining crop establishment while achieving effective weed control.
Field trials assessed the impact of sowing speed, furrow quality, seed placement and different pre-emergent herbicide options across a range of soil and seasonal conditions. Crop establishment, herbicide damage, weed control and grain yield were monitored to identify practical management strategies that reduce crop injury without compromising weed control.
The project also translated research findings into practical extension resources, enabling growers and advisers to better match herbicide choice and sowing practices to local conditions.
Key achievements and results:
This project improved understanding of how sowing practices influence the performance of pre-emergent herbicides under dry and early sowing conditions. The research confirmed that successful herbicide use relies not only on product selection, but also on achieving consistent seed placement, maintaining good furrow closure and operating sowing equipment in a way that minimises crop exposure to herbicides.
Across the trial program, growers gained practical guidance on managing the interaction between herbicide choice, sowing speed and seeding conditions to reduce crop damage while maintaining effective weed control. The findings reinforce the importance of machinery setup and attention to sowing quality, particularly as early sowing becomes more common across South Australian farming systems.
Key findings included:
- Demonstrated how sowing speed and furrow quality influence crop safety and the performance of pre-emergent herbicides under varying seasonal conditions.
- Improved understanding of the relationship between seed placement, herbicide position and crop establishment, helping reduce the risk of herbicide injury while maintaining weed control.
- Identified practical machinery and sowing management strategies that improve crop establishment when using pre-emergent herbicides in dry and early sowing systems.
- Produced practical technical resources to support growers and advisers in selecting suitable herbicide strategies and optimising seeding system setup.
- Contributed to improved confidence in integrating pre-emergent herbicides with dry and early sowing practices, supporting more resilient cropping systems.
You can access the project technical report below.
Further information:
Access the project technical report here: Understanding impacts of seeding conditions and sowing speed on pre-emergent herbicides for resilient farms
Stay up to date with this project: Hart Field Site Group.
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