Herbicide resistance

That’s why Australia’s agricultural sector has united to establish WeedSmart, an industry-led initiative to enhance on-farm practices and promote the long term sustainability of herbicide use.

Research partners, commercial organisations, government, advisors and growers have joined forces to ensure weed management is at the forefront of global farming practice.

Pioneer is one of the founding contributors of the WeedSmart Steering Group that draws on broad industry support to bring you leading tools and information.

Sustainable herbicide use will secure the viability of the Australian agricultural sector.

For further information visit: www.weedsmart.org.au

Integrating diversity

Over-reliance on a single weed control method causes increased selection pressure and development of resistant weed populations.

You also add the risk of consequential loss of a particular herbicide-tolerant system and you can even jeopardise your ability to grow a specific crop in a specific paddock.

Work proactively through integrated weed management practices to maintain or create diversity for successful management of a resistant weed population.

• Diversify modes of action (MOA): Avoid over-reliance on a single herbicide or weed management tool by using multiple MOAs and pre-emptively add non-chemical weed management elements to your weed control plan.
• Diversify crops: Rotate crop species and integrate as many different weed control options (chemical and cultural) as possible through all phases of the crop rotation.
• Diversify herbicide-tolerant traits: Rotate herbicide-tolerant traits with tolerance to different herbicide MOAs throughout the crop rotation. The following integrated weed management techniques are effective in reducing problems from herbicide resistant weed populations. It is best to use multiple practices to manage or delay resistance.

Herbicide resistance stewardship – integrating diversity

Know your paddocks; understand your weeds

• Understand your weed pressure and history
• Monitor problematic areas
• Identify weeds correctly
• Scout for weed escapes
• Test for resistance

Start with a clean paddock

• Start with a clean, weed-free paddock
• Introduce strategic cultivation and/or “double knock”
• Maintain a weed-free fallow through summer
• Plan crop rotations to control weed populations over multiple seasons

Staying clean – reduce early weed competition

• Ensure effective crop competition, through early vigour, plant density and nutrition
• Early vigour of Roundup Ready® and Clearfield® hybrids are far superior than triazine tolerant varieties
• Pre-emergent herbicides (trifluralin) reduce early season weed competition
• Minimise crop yield losses by reducing weed competition prior to canopy closure

Ensure best practice herbicide application

• Make every herbicide application count
• Use registered rates at the correct application growth stage
• Carefully manage spray drift and residues
• Proper application minimises potential for weed escapes

Do not allow weed escapes

• Aim for 100% control and monitor every spray event
• Treat every weed escape as if it is resistant
• Stop seed production to improve weed management
• Be prepared to sacrifice areas to avoid weed seed set

Commitment to zero – reducing your weed seed bank

• Manage our weed seed bank, get it low and keep it low
• Do not allow surviving weeds to set seed
• Take an integrated approach to control weed populations and prevent seed set
• Stop weed seed set to decrease weed population shifts

Keep it clean – seed and equipment hygiene

• Prevent the spread of herbicide-resistant weeds
• Ensure good on-farm hygiene of seed source and equipment
• Avoid the introduction of invasive weed species onto the farm in hay, seed and equipment

To remain sustainable we must integrate and diversify strategies for weed control and herbicide use.

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