Wheat in Kansas is rapidly moving through the vegetative stages of growth. Wheat in the southeastern and south central region is likely at jointing and approaching flag leaf emergence. In other areas of the state, the crop is still tillering or just beginning to joint. These growth stages mean it is time to ramp-up efforts to monitor for disease.
Survey work and field checks for this week indicate that diseases remain at low levels in most areas of the state. However, there are a few reports of rust activity that are cause for concern. In this case, both leaf rust and stripe rust (Figure 1) were discovered in research plots located in Reno county (Figure 2). The diseases were found in varieties of wheat known to be susceptible, meaning there is no evidence of changes in the populations of rust fungi to date. The disease was located in mid-canopy and still at low incidences (less than 1%).
Figure 1. Wheat with symptoms and signs of leaf rust and stripe rust. Images from Reno County near Hutchinson KS provided by Bob Bowden, USDA Wheat Pathologist.
The wheat at this location was just beginning to joint, which leaves plenty of time for these diseases build to damaging levels and move to the upper leaves where they can negatively affect crop yield.
Figure 2. Distribution of wheat stripe rust and leaf rust in Kansas, April 19.
While there is no immediate need for management activities, these reports are a helpful reminder that it is time for growers to intensify their efforts to monitor for disease. If weather conditions are favorable, the crop may need a fungicide to help protect yield potential. Scouting efforts should focus on wheat varieties known to be susceptible to the rust diseases and seed production fields that have value.
K-State Research and Extension have already increased their efforts to track the progress of rust in this year’s wheat crop. Stay tuned for more updates soon.
Erick DeWolf, Extension Plant Pathologist
dewolf1@ksu.edu
Tags: wheat wheat rust