What to Know: Sudden Death Syndrome and Brown Stem Rot
Because sudden death syndrome (SDS) and brown stem rot (BSR) continue to spread throughout the Midwest each year, now is a critical time to scout for signs of these diseases in your soybean fields. In Region 4, which covers northwestern Iowa and parts of Nebraska, SDS in particular was a big issue the last couple years, which means growers need to look for it again this year. Here’s what you need to know about SDS and BSR.
Plants typically become infected with SDS in the spring, a few weeks after planting; however, symptoms of the disease may not be detectible until late July or early August. Some of the symptoms can include discolored patches (often times yellow) on the leaves between the veins, leaves dropping prematurely, root rot, blue mold-like spots on the taproot, late-developing pods and smaller-than-normal seeds, which ultimately lead to reduced yield.
If you think you’ve detected SDS, contact your Stine regional sales agronomist to help confirm the disease. If SDS is confirmed, there really isn’t anything you can do for it this year, but in future years, there are preventive measures you can take to lessen the risk for SDS returning. Choosing soybean varieties that are SDS tolerant and seed treatments that are effective against the disease are options to discuss with your RSA. You’ll also want to take note of the problem areas so you can track those spots again next year. Typically, if SDS returns, it shows up in the same place each year.
BSR has a lot of similar symptoms to SDS, including leaf discoloration, decreased pods and smaller seeds. However, to determine if your fields have BSR or SDS, you need to split open the root and see if the pith and stem are brown or white. If it’s brown, then it’s likely BSR, if it’s white, then it’s probably SDS.
In addition to selecting varieties that are BSR tolerant and using seed treatments, growers can find some relief from the disease through crop rotation, including multiple years of corn on corn, and tillage.
For more information on how to detect and prevent SDS and BSR from occurring in your fields, talk to your regional sales agronomist.