10 June 1998
Yellow rust in winter wheat
I HAVE a field of winter wheat, Reaper variety. It is suffering badly
from yellow rust. What is the best possible treatment?
John Purslow, independent agronomist, Norfolk
Needless to say, treatment needs to be made at the very first opportunity. Opus (epoxiconazole) is the best triazole choice against yellow rust, but shouldnt leave the crop exposed to other disease. Use a half to three-quarters rate.
A triazole should be enough on its own but, for a belt-and-braces insurance, add a morpholine at a one third rate. Its better not to add Bravo (chlorothalonil) to the mix as it could slow the delivery of the triazole to the infection site.
After spraying, yellow rust can sometimes appear to get worse before it gets better, but then should dry up quite quickly.