By Andi Anderson
Iowa soybean farmers are being urged to remain vigilant for signs of Red Crown Rot (RCR), a soybean disease that has caused concern in several states surrounding Iowa. Although the disease has "NOT" yet been confirmed in Iowa, it has been detected in Illinois, Missouri, Wisconsin, and Minnesota, increasing the likelihood that it could eventually appear within the state.
Red Crown Rot is a serious soybean disease that can cause significant yield losses. To support early detection efforts, the Iowa Soybean Association, through the soybean checkoff program, is offering free Red Crown Rot testing for Iowa farmers. Samples submitted to the Iowa State University (ISU) Plant and Insect Diagnostic Clinic can be tested at no cost, helping producers identify potential infections before they become widespread.
One of the challenges with Red Crown Rot is that its symptoms closely resemble those of Sudden Death Syndrome (SDS). Infected soybean plants often develop yellow and brown discoloration between leaf veins. Farmers may also notice patches of yellowing plants throughout fields. As the disease progresses, leaves can wilt and affected plants may eventually die.
However, several key characteristics help distinguish Red Crown Rot from SDS. The disease causes reddish discoloration on soybean stems near the soil line, a symptom not associated with Sudden Death Syndrome. In some cases, small, round, red fungal structures may also be found on stems and roots. Additionally, infected plants can suffer extensive root damage, sometimes resulting in a condition known as "pencil roots," where much of the root system has rotted away.
Another important difference is that wilted leaves on plants affected by Red Crown Rot often remain attached to the stem. In contrast, plants with Sudden Death Syndrome typically lose their leaf blades while the leaf stalks remain attached.
Agricultural experts encourage farmers and agronomists to scout soybean fields regularly and watch for these distinguishing symptoms. If Red Crown Rot is suspected, growers should follow recommended sampling guidelines and submit properly prepared plant samples along with the required diagnostic clinic submission form. Samples should clearly indicate that testing is being requested for Red Crown Rot.
Because confirmation of the disease requires laboratory analysis, visual symptoms alone are not enough for a definitive diagnosis. Early detection is critical to understanding disease distribution and reducing potential impacts on soybean production.
The free testing initiative, supported by the United Soybean Board through the Iowa Soybean Association, provides Iowa farmers with an important tool for monitoring and managing emerging disease threats while helping safeguard the state's soybean industry.
Photo Credit: iowa-state-university
Categories: Iowa, Crops, Soybeans