AHDB has launched its Yellow Rust Watch List for winter wheat varieties on the Recommended List. By looking at the levels of yellow rust in trials around the UK, the Watch List identifies those varieties with a higher than expected level of the disease. This signifies that the variety may be prone to breakdown of resistance caused by the emergence of new yellow rust variants. Importantly, the List also shows this information against the national yellow rust ratings on the Recommended List. The higher the national rating, the more likely it is that new variants are not widespread, or have not been identified at all.
NIAB pathologist Dr Jane Thomas welcomed the introduction of the watch list. “It helps to identify those varieties that should be monitored closely and gives growers additional information derived from the Recommended List system to help manage varieties effectively.”
Dr Lucy James, who leads the UKCPVS project at NIAB, agreed. “It is clear that the current yellow rust population in the UK is highly variable. While some varieties still have high levels of resistance nationwide, some are more variable. We have seen a high number of samples from several varieties in the medium section of the Watch List during 2020. Tests on young plants with these samples are nearing completion, and results will be reported at the virtual UKCPVS Stakeholder meeting on 12th March 2021. Some samples will go on to be used on adult plants in the field this year, so we will then get a clear impression of how they will develop on RL material.”
The young plant data presented in the Watch List is derived from 2019 UKCPVS samples, but it is already clear that some of these classifications will change when the complete 2020 young plant results are assessed.
“UKCPVS data is critically dependent on receiving samples from crops and trials – we had a tremendous response during the difficult circumstance in 2020, and look forward to receiving more samples in 2021,” said Dr James.
Funded by AHDB and APHA, and managed by NIAB in Cambridge, the UK Cereal Pathogen Virulence Survey (UKCPVS) has been monitoring cereal rusts and mildews in the UK for more than 50 years. It provides an early warning system to growers and plant breeders of new races of disease that could overcome current variety resistance, and underpins the AHDB Recommended List disease resistance ratings.