Weed management diversity for the long-term viability of the Australian Lucerne Seed Industry

Summary

The Australia Lucerne Seed industry relies on effective weed control to maintain stand persistence, seed yield and crop longevity. Current production systems have a heavy dependence on a small range of herbicides that can be applied at critical crop stages. As a result, we already have evidence of herbicide resistance, whilst also having a reduction in management flexibility and vulnerability to future regulatory or market constraints. This risk has been highlighted by recent AgriFutures research on herbicide resistance in lucerne seed production systems in south-east South Australia (Boutsalis), which identified resistance as an emerging threat to the sustainability of current weed control practices.

This project will proactively investigate alternative herbicide options across three key weed control windows in commercial lucerne seed systems: crop establishment, winter cleaning and pre-harvest desiccation. By collecting locally relevant performance and crop safety data, the project aims to expand the range of validated weed management tools available to growers and advisors.

Paddock-based trials conducted over multiple locations and seasons will allow the assessment of weed control efficacy and lucerne tolerance within existing production systems. Results will support integrated weed management strategies that reduce reliance on any single chemistry and improve system resilience.

The project will be delivered through collaboration between Lucerne Australia, AgXtra and industry agronomists, with strong grower involvement and a comprehensive extension program. Outcomes will provide growers and advisors with practical, evidence-based options to support resistance management, improve decision-making and enhance long-term productivity and sustainability of the Australia lucerne seed industry.

Program

Pasture Seeds

Research Organisation

Lucerne Australia Inc.

Objective Summary

1. to evaluate the crop safety and weed control performance of alternative herbicide options for winter weed management in established lucerne seed crops.
2. To assess alternative herbicide options for pre-harvest desiccation and their impact on lucerne plant health and seed yield.
3. To assess pre-emergent herbicide options during lucerne establishment and their role in improving early weed control and stand persistence.
4. To generate practical, field-based data that supports integrated weed management and resistance mitigation strategies in lucerne seed crops
5. To improve grower and advisor confidence in used a broader range of weed management tools through in-field observations, extension and decision support.