By Farmers Weekly staff
NEW races of rhynchosporium could be overcoming Regina winter barleys formerly good resistance, warns NIAB.
Unexpectedly high levels of the disease in the south-west are showing up in DuPont/NIAB monitoring.
“This may be due to new races,” says NIABs plant pathologist John Clarkson.
With 10% of the varietys leaf area affected at one site in Cornwall, its resistance rating could be reduced from its current 8, he believes.
Intro, which has a rating of 6, has only 7% infection at the same site.
“Its a bit speculative at the moment, but Id feel a lot happier with Regina on 7,” says Mr Clarkson.