Fears that another race of yellow rust is attacking wheat crops this season were being expressed at Cereals 2011.
Infections in Warrior, currently a nine for yellow rust resistance, KWS Santiago and the candidate variety Torch, as well as some lesions on another nine-rated variety, Claire, had raised concerns, said Patrick Stephenson, an AICC agronomist in North Yorkshire.
“Warrior has been pretty bad, which is a bit disappointing, while Torch, which is well-named because it glows from a distance, has been worse than Oakley. So it is safe to say a big change has happened there.”
But it is Claire on which most attention would be focused, as it is the base for several varieties’ resistance. “In New Zealand there is a yellow rust race that has adapted to Claire, so it is always a concern when we see a few stripes on adult plants,” said Simon Oxley, HGCA’s new Recommended List manager.
However, Kerry Maguire, cereal pathologist at NIAB TAG, said infections on Claire were not like those seen in New Zealand. “But we have had a lot of reports of disease in varieties we wouldn’t expect. We need to confirm the variety is what it is said to be, and that the yellow rust will re-infect it before we can make any confirmation on new races.”
That wouldn’t be until much later in the year, she said. “It takes time to carry out the tests. But there is an indication something a bit different is going on this year. Whether it is due to weather, varieties or race change, we don’t know yet.”