Wheat Disease Update

Wheat Disease Update June 10, 2016

Wheat leaf rust on wheat
Figure 1. Leaf rust on wheat in a research plot at the ARDC on June 2
Leaf rust on barley
Figure 2. Leaf rust on barley in a research plot at the ARDC on June 9

The current warm to hot temperatures will considerably slow down stripe rust development, but favor leaf rust whose development has increased over the last three weeks.

There was severe leaf rust on wheat (Figure 1) and barley (Figure 2) during inspection of research plots at the Agricultural Research and Development Center (ARDC) near Mead (Saunders County) on June 2 and June 9.  By June 9, most leaves in unsprayed plots were dead or dying due to leaf rust (Figure 3). Other diseases observed were bacterial streak (Figure 4), black chaff (Figure 5), and Fusarium head blight (Figure 6). At this time it is too late to manage any of these diseases due to the advanced growth stage of wheat.

Wheat field with dieing leves due to leaf rust
Figure 3. Dead or dying leaves due to leaf rust in a wheat research plot at the ARDC on June 9
Bacterial streak in wheat
Figure 4. Bacterial streak on a wheat leaf at the ARDC on June 2. Note the shiny flakes representing dried bacterial ooze.  Also present are a few leaf rust pustules
Black chaff in wheat
Figure 5. Black chaff on a wheat head in a research plot at the ARDC on June 9
Fusarium head blight of wheat
Figure 6. Fusarium head blight on a susceptible wheat line (outermost row on the left of the center plot) in a breeding nursery at the ARDC on June 9. Each row in the plot is a genetically different wheat line