From tank-to-target: Making every glyphosate spray count this spring

This challenge took centre stage during a De Sangosse-sponsored seminar at CropTec. Building on the company’s ‘Clean Water. Clean Kill.’ stewardship campaign, the session brought together industry experts to explore how growers can optimise glyphosate applications – and why attention to detail has never mattered more.

Chaired by farmer and spray application specialist David Felce, the discussion featured contributions from Bayer, ADAS, and De Sangosse, all united by a common message: every stage, from tank-to-target, influences the final result.

Unique chemistry under pressure

Glyphosate has under-pinned modern arable systems since its introduction in 1974, providing a reliable foundation for weed control across a wide range of establishment approaches. But as David highlighted, its importance today goes far beyond routine use.

“Whatever system of establishment is used, glyphosate is critical to help provide a clean seedbed,” he explained. “With confirmed resistance cases now recorded, it’s vital we take every step to ensure it remains effective.”

That urgency is reinforced by the fact that glyphosate remains unique in its mode of action. As Bayer’s Roger Bradbury, herbicide technical lead, pointed out, there are no alternative actives offering the same activity – and none currently in development that could replace it.

Protecting glyphosate is therefore not just good practice – it is essential for the future of many farming systems.

Performance is more than just dose rate

A key takeaway from the seminar was that glyphosate performance is shaped by a combination of interacting factors, rather than any single decision.

Weed biology is central to this. Small actively growing weeds are typically easier to control, while larger or stressed plants – particularly those under drought or waterlogging – are less responsive. Applications made at the wrong growth stage, such as during stem extension, can also significantly reduce effectiveness by limiting movement of glyphosate to the roots.

Environmental conditions, product formulation and surfactant systems all play a role, as do tank mix partners and application technique.

“It’s easy to turn a weed brown,” noted Roger. “But delivering reliable, long-term control is much more difficult.

“That distinction is critical. Poor control does not just affect the immediate result – it creates survivors, and those survivors increase the risk of resistance developing.”

Resistance is a farm-level risk

Insights from John Cussans highlighted that glyphosate-resistant Italian ryegrass is already present in several locations in the UK – but its development is not inevitable.

Instead, resistance is being driven by decisions within individual farming systems. “It’s not just about time or exposure,” he explained. “It’s about how glyphosate is being used on individual farms.

“Common risk factors include heavy reliance on glyphosate, reduced cultivation systems, long periods of unmanaged stubble and repeated applications to large, well-established weeds.

“In these situations, glyphosate is often being asked to do more – and under less favourable conditions – increasing the likelihood of survivors and gradual shifts in sensitivity,” he said.

“For growers affected, the consequences of glyphosate resistance occurring can be significant, requiring increased cultivation, higher input costs and changes to system design.”

Clean water, better control

One of the key themes of the session – and a central pillar of the ‘Clean Water. Clean Kill.’ campaign – was the role of water quality in determining glyphosate performance.

As explained by Rob Suckling, commercial technical manager at De Sangosse, water hardness remains one of the most overlooked factors in spray application.

“Hardness is not pH – it’s the concentration of calcium and magnesium ions in the water. And those ions can bind with glyphosate, reducing its effectiveness before it even reaches the plant.

“This is particularly relevant across UK arable regions, where hard water is common. When glyphosate is mixed with hard water, these cations form less soluble complexes, reducing uptake through the leaf and ultimately lowering efficacy.”

Importantly, this process is invisible – but its impact can be significant.

Conditioning tank for success

Managing water quality starts with measurement. As highlighted during the seminar, growers cannot reliably judge water hardness without testing.

Simple tools such as TDS meters can provide a quick on-farm indication, while laboratory analysis offers a more detailed assessment of water composition.

Once understood, the use of effective water conditioners becomes critical. Products containing chelating or sequestering agents, such as X-Change, bind tightly to calcium and magnesium ions, preventing them from interfering with glyphosate.

Other approaches, such as straight ammonium sulphate, can offer partial mitigation but do not fully eliminate the issue. Meanwhile, inappropriate additions – particularly high rates of citric acid – can reduce performance further by destabilising the spray solution.

Equally important is mixing order. Water should be conditioned before glyphosate is added, ensuring the active ingredient remains fully available in solution.

From boom to target

Beyond the chemistry in the tank, application technique remains a key determinant of success. Drawing on his experience, David highlighted the importance of tailoring the application to the target.

“In dense canopies, such as overwintered cover crops, higher water volumes and coarser droplets along with angled nozzles can improve coverage and help reach weeds beneath the canopy. In contrast, smaller, exposed weeds may benefit from lower water volumes and finer droplets to maximise coverage and dose concentration.

“Across all situations, attention to detail is essential. Boom height, forward speed and nozzle choice all influence spray distribution, and small inaccuracies can result in uneven coverage and reduced control.

“Be clear about what you are trying to achieve. Glyphosate is too important to treat as just another pass,” he continued.

Stewardship mindset for spring

As growers move into the spring spraying window, the message from CropTec is clear. Optimising glyphosate performance is not about a single change, but about improving every stage of the process – from water quality and mixing to timing and application technique.

The ‘Clean Water. Clean Kill.’ campaign reflects this approach, encouraging growers to think more carefully about how glyphosate is used and how its performance can be protected.

Because ultimately, success is not just applying glyphosate. It’s about ensuring it works – every time, from tank to target.

For more information on the seminar, and testing and conditioning water, visit the De Sangosse website.

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