[Fhb-update_cgp] FHB Update from OK, 04/22/17

[FHB Update - Central GP, Hard Winter Wheat]

Wheat around Stillwater varies but appears to be in various stages of grain
formation. Based on talking to a number of producers across northern
Oklahoma, wheat heads have fully emerged but has not yet flowered or just
beginning to flower. Of course, as you go further west into the panhandle
the wheat is not as far along. I’m not sure as sure about central and
southern/southwestern OK, but I talked to one grower today from southwest OK
that indicted his wheat varied from starting to flower to kernels being
formed. This same grower indicated leaf rust is the most common disease he
has seen, and in some fields it is fairly heavy. Across northern OK,
producers indicated they are not finding severe levels of foliar disease
(primarily rust), but it is there (again, especially leaf rust). Brian Olson
(my A&P) spent all of yesterday rating wheat at Lahoma (15 miles west of
Enid in northern OK). He indicated there were some hot spots/areas of heavy
leaf rust, but that over all, leaf rust was light in the plots he was
rating. He also indicated he saw quite a bit of what he assumed to be
physiological leaf spot, which we tend to see more of in years with cloudy,
cool and rainy weather such as this year. Around Stillwater, I observed both
stripe rust and leaf rust, but more leaf than stripe. In some cases, there
was a mixture of both rusts on the same leaf.

Samples testing positive for Wheat streak mosaic virus (WSMV) have continued
to come into the Diagnostic Lab. To date, about 45 samples have been tested
for WSMV, High plains virus (HPV), and Barley yellow dwarf virus (BYDV).
Thirty-two of the 45 were positive for WSMV, 24 were positive for BYDV, and
2 were positive for HPV (co-infection with WSMV). Eleven of the samples were
positive for WSMV and BYDV. Most of these samples were received from central
and west-central Oklahoma, but it seems the area is expanding. For more
information on mite-transmitted wheat viruses such as WSM, please see OSU
Fact Sheet EPP-7328 (Wheat Streak Mosaic, High Plains Disease, and Triticum
Mosaic: Three Virus Diseases of Wheat in Oklahoma) available at
http://pods.dasnr.okstate.edu/docushare/dsweb/HomePage


--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 https://www.scabusa.org