Strip Rust on the Move in - Protect Susceptible Varieties

PROTECT susceptible spring wheat with fungicides applied at herbicide timing. A fungicide efficacy chart is attached to this email at this link. Variety ratings of spring wheat to stripe rust in 2014 are available in the 2014 Small Grain Research Report (also on our website). This cool, wet weather will allow rapid spread and infection to occur.

Stripe rust is spreading in western Idaho. Stephens is widely grown in western Idaho and is susceptible to stripe rust. Fields are being sprayed with fungicides but are getting close to the cut-off point for spraying with specific fungicides. Be aware of the PHI (pre-harvest interval) associated with the fungicide being applied - in some cases the PHI restriction may not be when crop is 50% flowering, but before. Know the crop growth stage prior to application to avoid residue issues and off-label applications. 

Brundage is also very susceptible to stripe rust, and Brundage fields in Twin Falls county are showing infection. Fields near Hansen, ID are showing severe BYD and starting to show stripe rust. Fields heavily infected with BYD and showing signs of stripe rust development will probably not be worth spraying with fungicides!! Depending upon the level of BYD, It would be wise to green chop those fields for feed and plant another crop. Check green chop materials for nitrate levels prior to feeding.

Pleasereport new additional stripe rust infected fields to me - include variety, crop growth stage and approximate location. And I really appreciate great pictures. That helps me keep the wheat community informed and prepared in case fungicides need to be scheduled for application. Clay Seamons sent me this picture - 

Juliet Marshall, Ph.D.

Associate Professor, Cereals Pathology and Agronomy

Idaho Falls R&E Center
1776 Science Drive Suite 205
Idaho Falls, ID 83402
208-529-8376 office
208-390-4859 cell