Yellow rust reports rise in winter wheat varieties across the UK

Yellow rust has been reported in several winter wheat varieties across the UK, with growers urged to monitor crops closely and be prepared to spray where necessary to keep the disease under control.

The Agriculture and Horticulture Development Board (AHDB) said early reports of the disease are emerging in many crops, warning that susceptible varieties may require treatment during the main fungicide programme.

Varieties vulnerable at the young plant stage may need yellow rust control during the T0 to T2 fungicide timings, even where they carry strong adult plant resistance ratings of 8 or 9 on the Recommended Lists (RL) for cereals and oilseeds.

For the most susceptible varieties, with resistance ratings of 3 or 4, growers may need to consider applying a pre-T0 fungicide spray where active yellow rust is already present.

AHDB advises growers to ensure any spray programme remains within the permitted number of applications for individual fungicide products and classes. If unsure, farmers should consult a BASIS-qualified agronomist.

The AHDB noted that resistance ratings in the Recommended Lists are based on adult plant resistance, which usually becomes active from the stem extension stage onwards.

This means varieties with strong adult resistance can still be vulnerable earlier in the season if they lack protection at the young plant stage.

Under the Recommended Lists classification, varieties are either resistant or susceptible to yellow rust during the early growth stages.

At present, RGT Guardsman is the only Recommended List variety classified as resistant to yellow rust at the young plant stage.

AHDB also highlighted that last year’s breakdown in varietal resistance has led to changes in how ratings are calculated for the 2026/27 Recommended Lists.

Due to this shift, the latest yellow rust adult plant resistance ratings are based solely on data from the 2025 season, rather than the usual three-year dataset.

The organisation said this adjustment, alongside other changes, was introduced to ensure the most reliable resistance ratings for growers.

To help farmers assess potential risks, AHDB has also published its latest yellow rust watch list, showing how varieties performed at their three worst-performing trial sites during 2025.

Paul Gosling, AHDB’s senior crop production systems scientist for the Recommended Lists, said some varieties with strong resistance ratings still performed poorly under certain conditions.

“Poor performance could be due to uncommon or new rust strains that could spread in later seasons,” he said.

“Some varieties with high levels of resistance (8) in RL 2026/27 rank near the bottom of the 2026 yellow rust watch list and should be monitored more closely.”

He added that disease pressures can change quickly.

“Rust populations are diverse and the situation can change rapidly,” he said.

“It’s important to check all varieties closely and report unusual disease levels to the UK Cereal Pathogen Virulence Survey.”

AHDB has also published a brown rust watch list, although brown rust levels remained relatively stable last season.

Growers are being encouraged to continue monitoring winter wheat crops closely throughout the spring, as early detection and timely fungicide applications will be key to managing outbreaks this season.