The latest Prairie wind trajectory cereal rust risk report is available for download now at the following link: June 22-28, 2021 report.
As of the week of June 22-28, 2021 the overall Prairie cereal rust risk assessment and need for in-crop scouting is as follows:
Pacific Northwest – There were a limited number of wind trajectories that passed over the PNW region and into the Prairies for June 22-28, 2021. Also, there is generally limited stripe rust development in the PNW, and hot dry conditions in a significant portion of the Prairie region. Thus, for the week of June 22-28, 2021 the risk of stripe rust appearance from the PNW is limited and scouting for this disease from this US region is generally not urgent. There have been some reports of stripe rust in barley from Washington State and Oregon and central to western Prairie producers and consultants may want to keep an eye out for this disease as barley fields progress.
Kansas-Nebraska corridor – Although stripe rust has developed in Kansas, and was progressing in Nebraska, winter wheat crops in these regions are moving towards later growth stages and harvest, thus active sporulation is declining or has stopped, especially in Kansas. There were no wind trajectories from this area into the Prairie region for June 22-28, 2021, as well as generally limited Prairie rainfall. As a consequence for the week of June 22-28, 2021, the risk of leaf and stripe rust appearance from the Kansas-Nebraska corridor is low. Note the Kansas winter wheat crop continues to be harvested, while harvesting of the Nebraska winter wheat crop has just started or will likely start over the next 1-2 weeks. Scouting for rusts from this US region is generally not urgent in the Prairie region. Given the advancing state of winter wheat development in Nebraska and continued harvesting in Kansas, this region generally no longer represents a significant source of rust inoculum for the Prairie region.
Note, hot dry conditions in many prairie regions have impacted crop development and may impact yield potential. In crops experiencing significant heat and drought stress, yield potentials and foliar disease risk may be limited and thus the need for fungicide application for leaf spot and rust management is likely limited. However, localized weather systems with rainfall may have occurred and as a consequence disease risk may be somewhat higher.