[Fhb-update_cgp] FHB Update from OK, 05/14/16

[FHB Update - Central GP, Hard Winter Wheat]

This past week in addition to being around Stillwater, I attended field days
in Canadian County (just west of Oklahoma City), Kay County (north of Ponca
City), Kingfisher County (northwest of Oklahoma City) and Major County (west
of Enid). Wheat I examined ranged from milk to medium dough. Some active
stripe rust (producing spores) was still present in Major County, but only
at low levels. Leaf rust is prevalent around Stillwater, with low levels of
leaf rust found in Kay and Major Counties.

Symptoms of barley yellow dwarf (BYD) also were observed at all locations.
As previously indicated, I observed only discolored (yellow to
reddish-purple) flag leaves and no stunting indicating infection of BYDV by
aphids occurred in the spring. One observation of note is that often with
BYD the flag leaf will be discolored but leaves below the flag remain green
as in the photo below. This is indeed BYD.

The Diagnostic lab also has continued to receive samples testing positive
for Wheat streak mosaic virus and/or High plains virus. These samples have
been from northern, northwestern and the panhandle regions of Oklahoma. For
more information, see Fact Sheet EPP-7328 (Wheat Streak Mosaic, High Plains
Disease, and Triticum Mosaic: Three Virus Diseases of Wheat in Oklahoma) at
http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-8987/EPP-7328.pdf

Finally, another disease that is making an appearance in Oklahoma this year
is take-all. I have not observed take-all in Oklahoma now for many years; in
fact, the last time we received a large number of samples of take-all was
back in the early 2000s. Take-all is favored by moist conditions and a
neutral to alkaline soil pH. Abundant moisture starting a year ago and in
areas of Oklahoma again this year have likely provided conditions favorable
for this disease in a few areas. Take-all will first show as white plants in
low-lying, wet areas after a period of hot days. I don’t think this will
be a significant disease in Oklahoma this year, but wanted to bring it to
your attention.


--Bob Hunger, Extension Plant Pathologist, Oklahoma State University

For more details, go to the FHB Risk assessment tool at
http://www.wheatscab.psu.edu

For the latest news and updates from the U.S. Wheat & Barley Scab
Initiative, go to http://www.scabusa.org