Rhyncho threat to south-west barley
Rhyncho threat to south-west barley
RHYNCHOSPORIUM is being found at worrying levels in the south west.
The disease is particularly noticeable on Intro, which has more than 10% of its leaf area affected on one Cornish site, according to DuPont/NIAB monitoring. Regina and Vertige, the other two varieties in the eight-site English survey, also have high levels there.
"There is obviously more than usual about and it came in earlier," says NIABs regional manager Duncan Connabeer. "My concern is that with a mild spell it could develop rapidly."
Although reluctant to offer a treatment threshold, he believes severely affected susceptible varieties could merit fungicide earlier than normal.
"If you were thinking about spraying at GS31/32, you may have to think about going at GS30/31. And if you were planning to use strobilurins alone, think again." A good curative active ingredient is also required, he says. *