Stripe Rust

From Juliet Marshall

With the spring weather perfect for small grain production, it is no surprise that stripe rust was finally confirmed in southern Idaho. The breeding line was significantly infected, but isolated (that is, infections were not widespread in the field). Most of the plots were just past flowering, and there is a long way to go for the winter crop to finish.

We are about 10-14 days behind previous years according to growing degree day estimates. Be sure to check plant growth stage prior to shutting off irrigation. You don't want to shut off irrigation too soon or too late - remember the general rule of thumb of "Full soil profile of moisture at soft dough before water shut off."We are mostly past the window of application for fungicides for winter wheat, and the stripe rust disease pressure is low. The greatest threat will be for susceptible spring wheat varieties. Scout spring wheat fields for infection, and report infections to University of Idaho personnel in order for us to track and report new occurrences.

Fungicide applications will likely not be required for moderately resistant and resistant varieties. Fungicides on the market are equally effective as stripe rust protectants, but as the flag leaves emerge, do not use strobilurin fungicides as that increases risk for DON contamination in grain from FHB or scab infection.  Remember to read and follow all label directions.