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DISEASE ID: Some diseases have characteristic symptoms that are easily identified; others may be mistaken for weather or chemical damage.

ISU updates guide on soybean diseases

Identifying diseases can be challenging as symptoms of some diseases appear similar to others.

Diseases reduce soybean yields every year and are responsible for reductions in grain and seed quality. Actual losses caused by disease vary annually, and disease occurrence is strongly influenced by weather conditions and other factors. Soybean plant foliage, stems, roots and seeds are all impacted by a variety of yield-reducing fungal, oomycete, bacterial and nematode pathogens.

Because management decisions differ depending on the disease, it’s important to properly identify which disease is present in a field. However, identification can be challenging as symptoms of some diseases appear similar to other diseases. Misdiagnosis can lead to possible implementation of management tactics that won’t work or aren’t needed, ultimately resulting in economic loss.

Bean disease infestations change
Iowa State University Extension and Outreach has released an updated version of the Soybean Diseases, IPM 4, publication to help farmers and other professionals in the agriculture industry identify and scout for disease threats to soybean production present in Iowa.

The publication includes scouting tips, disease descriptions, high-resolution images and general recommendations for management. Also included are illustrated disease cycles for many diseases, a foliar disease estimation chart, and soybean growth and development and staging information.

“Soybean disease issues change over time, and the information we have about diseases advances with new research,” says Adam Sisson, Extension specialist for the Integrated Pest Management Program at Iowa State University. “We updated ‘Soybean Diseases’ to reflect these changes and to improve the usefulness of the publication.”

“Several diseases not found in the previous version have been added, such as soybean vein necrosis and tobacco ringspot, along with new images and updates throughout,” says Daren Mueller, associate professor and Extension crop plant pathologist at Iowa State University.

Help available to identify diseases
The publication is available to buy online at the Extension Store. A hard copy of the publication costs $5, but there also is an option to order it in boxed quantities of 50 for a reduced price of $3.50 per publication. Printable downloads are $2.50 each.

Additional publications from ISU are available to help crop scouts as well as farmers and agribusiness personnel identify issues in the field. These include “Corn Diseases,” the “Corn and Soybean Field Guide,” and the “Weed Identification Field Guide.”

These resources are offered as single copies, printable downloads and as reduced-priced boxed quantities at the Iowa State Extension Online Store.

To stay updated on where specialists are seeing crop diseases, insects and weeds across Iowa, visit the ICM Blog, and look to ICM News for management recommendations based on current conditions.

Source: Iowa State University

TAGS: Crop Disease
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