Early reports of wheat rust in southern states
There have been several reports of wheat rust in the southern U.S. This may have implications for growers in Kansas. Below are some highlights of the reports from the last few weeks.
Stripe rust has been very active the past few months with reports from Louisiana, Arkansas, Mississippi, and Texas. The first report of stripe rust came from northern Louisiana where Trey Price, LSU wheat pathologist, noted a several foci of the disease in research plots near Monroe (northeastern, LA). These reports were followed by reports of stripe rust from Arkansas. Terry Spurlock, Extension plant pathologist for University of Arkansas, indicates that stripe is present in many counties in eastern Arkansas. Spurlock indicates the disease is severe in many fields. The situation appears to be similar across the border in Mississippi, where stripe rust was reported near Stoneville. There have also been reports of stripe rust activity in Texas. In this case, wheat breeder Amir Ibrahim with Texas A&M reported a small "hot spot" of stripe rust in research plots near Ennis, Texas (just south of Dallas).
Figure 1. Stripe rust. Photo by Erick DeWolf, K-State Research and Extension.
Bob Hunger, Extension plant pathologist with Oklahoma State University, reported leaf rust in Oklahoma this week. To the best of my knowledge, this is the first report of leaf rust in 2015. The report from Oklahoma indicates that leaf rust was present at low levels in research plots near Stillwater (north central, Okla.). The leaf rust was found in plots of Jagalene, which is known to be susceptible to leaf rust. The severity of the disease was less than 30 percent and affecting lower leaves. The report also indicates leaf rust activity in southwestern Oklahoma as well but there was less detail on varieties affected or disease severity for that area.
Implications for Kansas and other states
These reports of stripe rust and leaf rust in the southern U.S. are important because disease outbreaks in these areas can spread to neighboring states. The weather patterns in North America generally favor the spread rust in two major pathways. Rust outbreaks in Louisiana and Arkansas often spread up the Mississippi and Ohio River Valleys. Rust outbreaks in Texas and Oklahoma often spread north into the central and northern Great Plains. Producers in Kansas should be watching for more reports of disease in the south. If stripe rust or leaf rust continue to develop in the south, we will want to increase our local scouting activities. Scouting will be the key to timely management this spring.
Erick DeWolf, Extension Plant Pathologist