June 7, 2013

May 31 – June 6

Throughout the crop production season CropWatch will be sharing regular reports from the UNL Plant and Pest Diagnostic Clinic. Following is the first report.

Low soil temperatures coupled with high soil moisture have created ideal conditions for Pythium damping off in soybeans and corn. Scout fields now for stunted or wilted plants. If disease pressure is high enough, seedlings may even fail to emerge above the soil line.

Diagnosing Pythium diseases and differentiating them from other seedling diseases in the field can be difficult  At least 14 species of Pythium can cause seedling blight and root rot. Consider submitting a sample to the UNL Plant and Pest Diagnostic Clinic for positive identification.

Reports

The following diseases were repported in samples submitted to the PPDC.

Corn
Central District — Pythium damping off
Northeast District — Fusarium damping off

Soybean
Central District and East Central District — Pythium damping off

Wheat
Southeast District — frost damage
Southeast District — wheat streak mosaic virus

Resources

• For more information on corn nematodes and how to take and prepare crop samples for diagnostic analysis, see this week's Market Journal article for segments with the author and with Tamra Jackson-Ziems, UNL Extension plant pathologist.
• For more information on Pythium, see Pythium and Other Seedling Diseases in Crops.
• For information on submitting samples to the PPDC, see the May 24 CropWatch article.

Kevin Korus
Coordinator, UNL Plant and Pest Diagnostic Clinic