In a year when every last crop input will need to be justified, the multi-site fungicide ARIZONA (500g/l folpet) is one crop protection product that arable growers can rely on to pay for itself by boosting yields by 0.3t/ha. ADAMA’s UK Technical Manager, David Griffiths explains why this tried and tested active ingredient should be on every wheat and barley grower’s radar in 2026.

“After the drought induced challenges of 2025, and with wheat markets showing little sign of improvement after last year’s drop, UK arable growers are looking closely at this year’s crop input expenditure,” David explains.

“We understand this sentiment and encourage growers and agronomists to appraise the return on investment of each and every penny spent on crop protection. It's also important to understand what the potential of the crop is in order to make the right decisions to maximise output. UK growers currently have some fantastic looking crops in the ground, and it would be a shame to let their yield potential fall by the wayside simply because they weren’t adequately protected against diseases such as septoria in wheat and ramularia and rhynchosporium in barley.”

Last year’s drought meant cereal disease pressure was exceptionally low, so it’s not surprising growers are questioning their level of fungicide spend, David says. “But, with crops drilled earlier, and this year starting wet and mild, disease pressure could explode, especially as the inoculum for diseases like septoria will already be present in crops, waiting for the opportunity to rise through the canopy as soon as plants start growing in the spring.”

One of the main reasons for including a multi-site fungicide in spring spray programmes has been to protect single site chemistries such as azoles, SDHIs and Qil actives. “That’s an important consideration,” David adds, “but in the current economic climate, that isn’t enough on its own to warrant folpet’s inclusion.

“When selecting suitable products for spring disease control programmes, each input should earn its place, which is why ADAMA has been testing ARIZONA to assess its real value in terms of crop performance and its ability to enhance yield. Seven years of trials data has proven that ARIZONA not only protects newer chemistries, but it also returns an average yield benefit of just over 0.3t/ha.”

David explains that a yield improvement can be expected even in very dry years when latent disease pressure is low: “ARIZONA’s performance is remarkably consistent, irrespective of how the weather unfolds. In high pressure seasons such as the wet years of 2023 and 2024 its inclusion is a no-brainer. Folpet also pays for itself in dry years like 2025 when it still contributed to more resilient crops and higher yields.”

In wheat, ARIZONA can be used from T0 through to T2, but the key timings for its inclusion to protect against septoria are at T1 and T2: “Applying folpet at T1 delivers the biggest yield uplift, with its inclusion at T2 also providing a valuable increase in crop output,” David explains. “A programmed approach of inclusion at T1 and T2 will provide the very best levels of disease protection, with the T0 timing also useful in scenarios where disease pressure is elevated earlier in the season.

“A robust fungicide application at the T2 timing will help to keep the crop’s upper canopy greener for longer, contributing to higher yields and enhanced crop quality,” David adds. “T2 treatments should therefore contain a combination of modes of action including curative single-site active ingredients such as an azole and an SDHI or Qil fungicide, plus a multi-site, chiefly folpet.”

In barley, ARIZONA should be applied at T2 to control ramularia, net blotch and rhynchosporium, but it can also be used at T1 to give protection against rhynchosporium and net blotch, and to provide extra protection against ramularia in high-risk situations. It can also be used at T3 to maintain canopy protection in situations where the season is extended.

“From a resistance perspective, ramularia is more aggressive at breaking single site chemistries than septoria, so including a multi-site chemistry is even more valuable in barley,” David concludes. “And, just as it does in wheat, ARIZONA (500g/l folpet) provides a proven uplift in barley yields to ensure grain stores are full at the end of harvest.”