Recent trial results from ADAS found that when Revystar XE (Xemium + Revysol) was included in winter wheat fungicide programmes, there was an uplift in yield, even where the application of nitrogen was cut back.

Dr Julie Smith, a senior plant pathology researcher at ADAS, commented: “If you are going to reduce your nitrogen this year, don’t be tempted to be too light with the fungicide programmes because Revystar XE can increase yield at commercial nitrogen rates compared with competitors.”

Independent trials undertaken in 2021 looked at the interaction of N and fungicides, with Gravity, which had a Recommended List (RL) rating of 4.7 for septoria and Graham, with a RL rating of 6.7.

“We applied five different N rates ranging from 37 kgN/ha up to 370 kgN/ha at the same timings as on the commercial crop and three different fungicide treatments, untreated, Revystar XE and Ascra Xpro with applications solely at T2," she said.

“There were responses to N, of course, but on top of that Revystar XE gave increases in healthy area duration (HAD) and yield above the untreated and above the Ascra Xpro.

"The HAD values and yield were generally lower for Gravity, compared with Graham, but whether you are sowing a susceptible or a resistant variety you get the benefits from the N and Revystar XI interactions,” she pointed out.

In the UK, winter wheat is considered to be a source limited crop which doesn’t have enough green leaf area to fulfil its yield capacity.

“If we can do something to increase or maintain that green area for a bit longer then we can generally push up yield,” she added.

Ensuring fungicide programmes work to their optimum is, therefore, essential pointed out Dr Jon Helliwell, BASF's business development manager for cereal fungicides. He pointed out:“The impact of maintaining a healthy canopy is immense on yield and the bottom line and the fungicide programme is key to this.”

In order to understand how different active ingredients are performing and also how effectively they can protect other partner fungicides, BASF collect and monitor septoria isolates from across the UK each year, to gauge how the population is evolving.

“The performance of the isopropanol- azole Revysol is unchanged over the last four years for the UK range of septoria isolates, with sensitivity remaining solid with no movement in the dose required to inhibit 50% of the population (ED50) and importantly, results from field performance trials remain very strong.

"A full dose of Revysol gave around 80% control of septoria, compared to circa 20% for prothioconazole,” said Dr Helliwell.

"Resistance monitoring had shown there was a further shift in prothioconazole-desthio sensitivity and this showed a further increased median ED50 in 2021 coupled with a reduction in field performance.

"This has implications for the foundation of fungicide programmes and the strongest azole, Revysol, should be utilised both to maintain the strongest levels of disease control, whilst protecting at risk modes of action partnered with it,” he said

Disease monitoring work between 2017-2019 at T2 showed a gradual decline in performance of conventional fungicides. In 2020, there was a clear differentiation between Revystar XE and conventional products in Ascra Xpro.