Soybeans throughout the area have shown some Sudden Death Syndrome. The fungus that causes SDS in soybeans can survive through the winter in the soil, as cysts from mature soybean roots and in crop residues.
Scout's Report 8/12: Ear tip filling, Northern corn leaf blight and Japanese Beetles in Indiana
When temperatures rise in the spring, the fungi begin to infect the new roots and reproduce underground. All of this will go on without showing any symptoms. When the soybeans begin to flower, the leaves will begin to turn yellow and show mottling, or more than one color, in the leaf tissue. This is the viewable result of toxins taken up through the roots and entering the stem.
The toxins from the fungus will not actually mobilize through a plant, even though the leaves show the first symptoms. The next phase of symptoms includes leaves dying and turning all brown. Sometime they will even fall to the ground and leave the stems standing alone.
Symptoms that are easily seen from the edge of a field may lead to a misdiagnosis. Chemical burn or another disease may be the true cause of the yellow or brown leaves. Brown stem rot is often confused with SDS because of the very similar look. By cutting open the stem and main root of the soybean plant, you can examine the pith.
If it is white or a light tan, SDS is likely the culprit; if the pith is a chocolate brown inside, brown stem rot but is more likely to have caused that leaf damage. Chemical damage can cause the leaf discoloration as well but this will usually have more of a distinct pattern in a field of affected and not affected plants.
Managing SDS can be a challenge for any farmer. Foliar fungicide applications will not affect the disease; however, in furrow fungicides can make some impact.
Seed treatments are a good option along with well-planned practices to prevent SDS. Planning ahead is key for controlling and preventing SDS. Choosing varieties that are more resistant to the fungus, changing tillage practices, rotating crops, and evaluating planting date are all ways to be proactive with the dangerous disease of Sudden Death Syndrome in soybeans.
Work with your agronomist and other farmers to create a plan to manage the risks of SDS in your operation.
Scout's Report 8/5: Corn and soybean insects make their move this week
This is my final crop scout report of the summer. I have more than appreciated the opportunity to share my experiences through writing. I hope that by following my reports each week this summer, you have learned a little bit and felt closer to the fields, rain, crops, insects and other farmers through reading.
Thank you to Beck's for such a wonderful internship!
Kettler was a summer intern for Beck's. She writes form Tipton. She is returning as a junior to Purdue this fall in ag econ and agronomy. Look for her on the sidelines of Purdue sporting events – she is also a Purdue cheerleader.