Yellow rust alert: Disease reported in winter wheat across UK

Reports of yellow rust in several winter wheat varieties are coming in across the UK.

Varieties susceptible at the young plant stage may need fungicide treatment during the T0 to T2 fungicide period to manage the disease, even if they have a robust disease resistance rating of 8s or 9s. 

For the most susceptible varieties, which have ratings of 3 or 4, growers should consider a pre-T0 spray, where yellow rust is active.

However, it is important to consider the maximum permitted number of applications for some fungicide products and classes across the programme.

See also: Yellow rust forces rethink of wheat fungicide programmes

The main RL disease resistance ratings (1 to 9 scale) are based on adult plant resistance, which kicks in from stem extension onwards. The timing is specific to individual varieties.

For young plant resistance, varieties are either classified as resistant or susceptible. Currently, the variety Guardsman from RGT is the only variety on the Recommended List (RL) which is resistant to yellow rust at the young plant stage.

Due to the breakdown in varietal resistance last year, the RL 2026-27 yellow rust adult plant disease resistance rating calculations only use data collected in 2025, rather than the standard three-year data set. AHDB also made other changes to provide the most robust ratings.

Paul Gosling, AHDB’s senior crop production systems scientist for the RL, says: “Poor performance could be due to uncommon or new rust strains that could spread in later seasons.

“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.”

Rust populations are diverse and the situation can change rapidly. It’s important to check all varieties closely and report unusual disease levels to the UK Cereal Pathogen Virulence Survey (UKCPVS).