Nathan Kleczewski, Extension Specialist – Plant Pathology; firstname.lastname@example.org
Stripe rust was recently confirmed in wheat in Robeson County, NC on the border with South Carolina. The disease was found in a wheat trial on a susceptible variety, SS 8404.
Stripe rust is an obligate pathogen requiring cool, moist weather to infect tissues and cause disease. It does not overwinter in Delaware or Maryland and must be blown in each year from warmer areas in the south. It will take time for the disease to develop and build, and additional time for the disease to move into the region, if it does at all. That being said, this is simply a note that the disease is active in the region but not at a concerning level. If the disease moves into the area and you have a susceptible variety, a fungicide application may be required, especially if the disease starts early and conditions are cool (50-60°F) and wet. With this knowledge, growers should keep several things in mind.
The first thing for you to do is to check your varieties. If you have a variety with good to excellent stripe rust resistance, fungicide applications are not likely to provide a benefit. Last year we were able to rate our wheat varieties for stripe rust resistance. This data can be found by clicking here: DE Wheat Variety Trial Disease Ratings. In this document a 0 indicates that that the disease was completely absent and a 5 indicates that the disease was present at very high levels levels. Those with varieties between 0 and 2 should feel good about their stripe rust resistance and not be overly concerned about this disease. Those varieties with a rating higher than 3 should keep stripe rust in mind. If you recall, last year we saw pronounced stripe rust in susceptible varieties, but resistant varieties were nearly untouched.
The next thing you should do is plan on scouting your fields regularly. This disease can damage plants quickly on susceptible varieties under conducive conditions (see Shirley from 2016). If you aren’t planning on a fungicide application and have a susceptible variety, definitely keep an eye on your fields. Scouting fields is always a good idea, regardless of whether a disease such as stripe rust is detected in surrounding states.
The big thing now is to be prepared. At this point there is no need to be spraying anything.
For more information on stripe rust management and images, see the wheat stripe rust factsheet from the University of Delaware.