UK: AHDB has issued a yellow rust watch list to help flag winter wheat varieties most likely to perform out of line with the disease ratings published in the AHDB Recommended Lists

The watch list, which orders varieties based on yellow rust levels from the three worst RL trials (for each variety), can help identify those most likely to benefit from closer monitoring.

It follows the development of a new rating calculation approach that better reflects the diverse and dynamic nature of the UK’s rust populations, announced at the launch of the online edition of the RL 2021/22 in December.

Discussions on the latest twists and turns in the yellow rust story will also feature as part of the UK Cereal Pathogen Virulence Survey (UKCPVS) stakeholder meeting, which takes place online on 12 March 2021.

Catherine Harries, who manages disease research at AHDB, said: “The online wheat yellow rust watch list provides a way to flag unusual levels of yellow rust seen in some varieties in some trials, compared with what the headline disease rating would otherwise suggest. This extra layer of information can provide a valuable early warning of a potential change in the UK’s race structure and help focus in-season management strategies.

“Following the introduction of the new rating calculation approach, it is good to see that the watch list shows that varieties are performing broadly in line with the RL ratings. However, as the situation can change rapidly, it is important to monitor all crops closely and report unexpected levels of disease to the UKCPVS.”

The UKCPVS was set up to detect and warn the industry about new races of rusts and mildew that are capable of causing disease on previously resistant cereal varieties. Targeted at breeders, crop scientists and technical agronomists, the annual stakeholder meeting reports on results from recent NIAB-led screens. This year, the event also includes two presentations on the management of cereal rusts in the field.

AHDB plans to update the watch list, which features all recommended winter wheat varieties, annually, following the release of the latest RL. The current watch list uses trial data from the 2019/20 season. Ratings are based on a three-year data set.

The RL 2021/22 booklet edition is now available. To download it or to access the watch list, visit ahdb.org.uk/rl

To find out more about the UKCPVS, including the stakeholder event, visit ahdb.org.uk/ukcpvs