Sunday, June 8, 2008

Wheat Disease Update For June

We are currently in the process of examining the winter wheat variety trials that are at Arlington, Chilton, Janesville and Lancaster for foliar diseases. So far, we have completed assessments at Arlington. The growth stage ranged from Feekes 9 (when the ligule of the flag leaf is visible) to Feekes 10.3 to 10.4 (almost full head emergence). From these assessments, the two main fungal diseases observed have been Septoria leaf blotch and powdery mildew. Tan spot has also been noted in some plots. However, we have also noted the presence of wheat leaf rust and wheat stripe rust. For these assessments, we measured the severity, which is the area of leaf tissue infected on the flag leaf and also the leaf directly below the flag leaf. For wheat leaf rust, symptoms were noted on 40% and 47% of plots the two leaves, respectively, with the severity ranging upwards of 10-15% in some plots. Wheat stripe rust was noted in only a few plots, and with only 3-4 pustules. We will continue to actively monitor for further rust development in the different wheat studies and locations.