Spring fungicide decisions have always been a balancing act for growers: protect crops early and thoroughly or hold back inputs and risk disease pressure building later. But with commodity prices under pressure, tighter margins and changing disease dynamics, that decision feels sharper than ever.
Yellow rust remains a persistent threat across many popular wheat varieties, while earlier drilling dates have increased the risk of septoria. Against that backdrop, agronomy firm Agrii has been testing whether the latest farm technologies can help growers refine fungicide programmes to optimise spend without compromising yield.
The results, emerging from the company’s Digital Technology Farm (DTF) host site in the UK, point to a clear conclusion: the biggest gains come from smarter timing and targeting, rather than simply applying less product.
Technology layered onto agronomy
Now in its third year, Agrii’s Digital Technology Farm programme brings together disease modelling, in-field sensing and agronomic assessment to guide fungicide decision‑making.
Before a sprayer goes near the crop, multiple data streams are assessed. Variety choice provides an initial understanding of likely disease pressure, while Agrii’s Contour platform applies a traffic‑light system to indicate real‑time risk levels for key wheat diseases.
But modelling alone is not enough. The trials also make use of BioScout, a smart spore‑trapping device positioned within the crop. Airborne fungal spores are captured on sticky tape and analysed using microscopy and artificial intelligence to automatically identify disease species present in the field.
Crucially, this data is not taken in isolation. Field walking and agronomic judgement remain central to the final decision‑making process.
By combining disease risk modelling, spore detection and physical crop observation, Agrii’s team aimed to build a fungicide programme that responded to what was actually happening in the field and when.
Holding back early when conditions allow
Last spring’s dry weather played a decisive role in shaping the programme. Disease pressure remained lower than expected early in the season, allowing fungicide inputs at the T0 and T1 timings to be reduced.
Rather than removing protection altogether, the early strategy focused on crop health and resilience. Plant nutrition and biological support took priority, with applications including micronutrients and the plant health elicitor Innocul8, which is designed to stimulate the plant’s own defence responses rather than directly target pathogens.
This approach reflected one of the central questions behind the trials: can better information give growers the confidence to pause early fungicide spend when risk is genuinely low?
In this case, the answer was yes – but with an important caveat.
Fungicide spend wasn’t removed – it was shifted
As the season progressed, disease dynamics changed. Yellow rust became active in the crop, triggering a decisive shift back to a more conventional fungicide approach.
At T2, the programme moved to an SDHI and azole mix, followed by a prothioconazole and tebuconazole combination at T3.
Rather than treating fungicide cost reduction as the primary objective, spend was reallocated later in the programme once disease pressure justified intervention. This flexibility, enabled by real‑time monitoring and risk assessment, proved to be one of the key lessons from the trial.
In other words, it was not about using less fungicide overall, but about deploying it when it delivered the greatest return.
When late protection doesn’t pay
The trials also surfaced a valuable insight around late‑season crop management during dry conditions.
Pushing for late green leaf area retention did not deliver the expected yield benefit, as moisture stress meant the crop droughted out before that protection could translate into grain fill.
The lesson was a practical one: under drought stress, protecting late leaf layers will not always convert into yield, even if disease pressure is present. Once again, timing and context mattered more than following a fixed programme.
Yield tells the real story
By the end of the season, the overall cost of the fungicide programme in the DTF trial area was broadly similar to the farm’s standard approach. Savings made early were offset by spend on biologicals, nutrition and later fungicide applications.
But performance, not input cost, was the decisive metric.
The Digital Technology Farm trial area yielded 0.8 t/ha more than the farm standard.
That uplift was attributed to stronger overall crop health, driven by a combination of micronutrient support, Innocul8’s influence on plant defence responses, and a two‑layer variable‑rate nitrogen strategy.
Technology supports decisions – it doesn’t replace them
The clearest message from Agrii’s work is that technology does not replace agronomy; it strengthens it.
Disease modelling, spore detection and digital tools add valuable layers of insight, particularly around timing and risk, but they only deliver value when combined with on‑farm observation and experience.
For growers under pressure to justify every penny spent on crop protection, the promise of these systems is not radical input reduction, but greater confidence to adjust programmes as conditions change.
