T.K. Turkington, AAFC Lacombe, R. Aboukhaddour, AAFC Lethbridge, and B. McCallum, AAFC Morden.
Three previous PCDMN blog posts have highlighted potential emerging stripe rust issues in the USA; unfortunately this may mean stripe rust issues for Prairie wheat growers. As mentioned previously stripe rust risk forecasts from Dr. Chen, USDA-ARS and Washington State University (WSU), indicated the risk of stripe rust for 2024 for the eastern PNW is severe and susceptible winter wheat varieties will potentially incur yield losses (https://www.wawg.org/stripe-rust-report-warmer-november-december-dont-bode-well-for-susceptible-varieties/; https://smallgrains.wsu.edu/first-stripe-rust-forecast-of-the-2024-season/; https://www.wawg.org/march-1-stripe-rust-forecast-calling-for-epidemic-levels-for-eastern-washington/). In addition, Dr. Chen has reported stripe rust symptoms in research and disease monitoring trials in Washington State including eastern regions, as well as in NE Oregon (Umatilla County). Both Drs. Chen and Murray, WSU, indicated that not since February 2011 have symptoms of stripe rust been observed this early (https://smallgrains.wsu.edu/stripe-rust-324/; Stripe rust report 4/13: Stripe rust widely occurring in the PNW | WAWG; https://smallgrains.wsu.edu/stripe-rust-24/; https://twitter.com/WSUWheatDoc/status/1781009581860352487). Dr. C. Hagerty the Columbia Basin Agricultural Research Centre (CBARC), Oregon State University also reported stripe rust on susceptible lines at the CBARC, Pendleton, OR and encouraged growers to scout and consider fungicide application (https://osu-wams-blogs-uploads.s3.amazonaws.com/blogs.dir/2823/files/2024/04/2024_April_Rust.pdf). Recent X (formerly Twitter) posts from Dr. D. Larkin, wheat Breeder Limagrain, April 18, 2024, (https://twitter.com/dylarkin/status/1781102306593050890) Overall, rust risk forecasts for the PNW and the early occurrence of significant symptoms suggest the PNW may be an important source of stripe rust inoculum for Prairie wheat growers in 2024.
As mentioned previously in PCDMN blog posts, stripe rust is also being observed in other areas of the USA including the Texas to Kansas corridor. There have been multiple reports of stripe rust in Texas and other southcentral States and these early observations suggest that these areas of the US may experience severe stripe rust epidemics if conducive weather occurs (S. Baker, Stripe rust at Chillicothe, TX, CEREAL-RUST-SURVEY@LISTS.UMN.EDU, February 26, 2024; https://twitter.com/J_SBaker/status/1752818506674929882; Dr. O. Fajolu USDA, St. Paul, MN, Cereal Rust Bulletin #1, April 15, 2024, https://www.ars.usda.gov/ARSUserFiles/50620500/CRBs/2024%20CRB%20April%2015.pdf). Stripe rust is now being reported in Oklahoma and Kansas in a number of areas in March and April (OSU Wheat Pathology, https://twitter.com/OSUwheatdisease/status/1774552781137035533, https://twitter.com/OSUwheatdisease/status/1770869304529199247, https://twitter.com/OSUwheatdisease/status/1776637764496412894; A. Hixson, BASF, https://twitter.com/hixsona/status/1778224217810522353; J. Coltrain, Syngenta, https://twitter.com/josh_coltrain/status/1776240076290216134, https://twitter.com/josh_coltrain/status/1780357856912363741 and https://twitter.com/josh_coltrain/status/1780330445550301428; R. French, French Agronomics, https://twitter.com/frenchrw/status/1779939164655657407; J. Kohls, Wheat Breeder Syngenta, https://twitter.com/jkohls1/status/1779939113589686423; KSU Wheat Pathology, https://twitter.com/KSUWheatDisease/status/1778171057674797477; J. Seiler, KSU, https://twitter.com/SGAgAgent/status/1777742988510187728).
Dr. M. Aoun, OSU recently reported that stripe rust potentials are high in Oklahoma and timely scouting by farmers is encouraged (https://spotlight.okstate.edu/wheat-pathology/2024/04/02/wheat-disease-update-2-april-2024/, https://www.farms.com/videos/crops/scout-for-stripe-rust-209386.aspx). Drs. S. Liu, B. Gerrish, and J. Rudd, Texas A&M University, April 2024, have mainly reported stripe rust, but also leaf and stem rust of wheat, and crown and stem rust of oat in Texas (https://varietytesting.tamu.edu/wp-content/uploads/sites/17/2024-Wheat-Rust-Report.pdf).
In western Canada, early development of stripe rust in disease nurseries at Abbotsford and Creston, BC have been reported by Dr. G. Brar, U of Alberta, formerly of UBC, and likely reflect overwintering on winter wheat breeding lines (https://x.com/gurcharn_brar/status/1779910374051209644).
You can keep up-to-date with Prairie cereal rust risk via
PCDMN cereal rust risk forecasts that are posted to this blog from mid-May to
early July each year and can be found at https://prairiecropdisease.blogspot.com/p/cereal-rust-risk-report.html. Key management strategies for cereal rusts
include host resistance, scouting and awareness of emerging rust issues, and
timely fungicide application. It is advised that Prairie producers check
the stripe rust resistance rating of the winter and spring wheat varieties they
are or will be growing. Timely scouting and consideration of fungicide
use are advised for the 2024 growing season, especially for varieties that are
susceptible to moderately susceptible to stripe rust. As of April 19, 2024, winter wheat fields
that have started to regrow are most at risk, fortunately most current winter
wheat varieties have intermediate to high levels of resistance, although
Radiant, CDC Buteo, AAC Elevate, Broadview, and CDC Falcon are rated as
susceptible (https://www.seed.ab.ca/variety-data/cereals/;
https://saskseed.ca/wp-content/uploads/2020/12/2024-Varieties-of-Grain-Crops.pdf;
https://www.seedmb.ca/pdf-editions-and-separate-section-pdfs/).
