[Fhb-update_cgp] FHB Update from OK, 04/23/15

[FHB Update - Central GP, Hard Winter Wheat]

This past week in Oklahoma was cool and moist with some continued rain and
slightly warmer temperatures forecast through the weekend. Wheat is mostly
at flowering around Stillwater but by early next week will likely be past
flowering. From what I hear across the state, wheat is quickly approaching,
at, or will be quickly past flowering (depending on what part of the state,
when planted, and how much drought stress was endured).
 Around Stillwater there has been an increase in stripe rust and powdery
mildew (especially stripe rust). Leaf rust also has increased, but not to
the same extent (incidence or severity) as stripe rust. Dr. Brett Carver
(OSU Wheat Breeder) indicated he saw significant stripe rust in his
nurseries at Lahoma (north-central OK). Gary Strickland (Jackson County Extn
Educator) also has observed an increase in stripe rust (and to a lesser
extent, leaf rust) in far southwestern Oklahoma. My impression is that
stripe rust has activated again with the cool and wet weather, and continues
to spread across Oklahoma. This Thursday and Friday there will be field days
in central Oklahoma, so look for a more extensive report next week.
 Mite-transmitted viruses also are prevalent in Oklahoma this year.
Yesterday when in nurseries here at Stillwater I noticed occasional trapped
heads scattered throughout the field. In observing these in the lab using a
dissecting scope, I found wheat curl mites associated with these trapped
heads. Although only sporadic around Stillwater, the Diagnostic Lab has
received multiple samples that they confirmed for presence of Wheat streak
mosaic virus, Wheat mosaic virus (High plains virus), and/or Barley yellow
dwarf virus. This includes samples from Grady, Noble, Grant, Texas and Woods
Counties. I would refer you to EPP-7328 (Wheat Streak Mosaic, High Plains
Disease, and Triticum Mosaic: Three Virus Diseases of Wheat in Oklahoma)
available at http://osufacts.okstate.edu for more information on these
mite-transmitted viruses.

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

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