Keep an eye on late season disease progression in crops

By Robert Waller, Seed Genetics Direct sales agronomist

As we enter into the final laps of this growing season, it is important to keep assessing the conditions of your crops. We’ve had early wet, mid-summer heat, dry then wet depending on where you are, with extremely different conditions all over the state. Check on your crops for progressing diseases, especially tar spot in corn.

We continue to evaluate our current lineup and new experimental hybrids in many research plots across the Indiana and Ohio geographies and need as many observations as possible to help select products that have improved tolerance to this new disease. Please respond with any comments and observations from your fields to help us get a better handle on how our lineup is handling this new challenge.

Also keep an eye out for gray leaf spot and northern corn leaf blight so that we can better assess the impact of those diseases. Share your observations within our group of seedsmen and customers so that we fully understand how our hybrids are performing under disease pressure. As the corn crop gets closer to being harvest ready, be sure to examine plant integrity and stalk strength. You can use the pinch test and/or push test to see where stalk lodging issues may become a problem. Pinch the stalk to test for firmness in the middle of the plant or push lightly on the stalk to make sure it does not fall over easily. This will help in determining which fields you should harvest first. These are the main diseases I have noticed walking plots and taking notes, however if you notice anything unusual or other diseases, please let us know what you are seeing and where it is occurring.

In soybean, I have not seen a tremendous amount of disease or insect pressure but still be on the lookout for issues that can still arise. There are a few cases of sudden death syndrome (SDS) showing up. This disease is generally a bigger problem in earlier planted soybean fields, but can show up in late planted soybean as well. Look for interveinal  chlorosis and leaf death on the upper leaves. Check stems to rule out brown stem rot (BSR) that has similar foliar symptoms are similar to SDS. With SDS, there can be some internal stem discoloration near the base, but it usually does not progress very far up the stem versus the typical brown tissue in the internal stem, with BSR progress upward and usually darker near the nodes. As SDS progresses, the leaves with eventually fall off and the petioles will remain attached.

I have seen some frogeye leaf spot, so be on the lookout for that disease. We rely on field observations to assess this disease, so let us know when you see it and what variety it is showing up in. We refresh our soybean lineup frequently and need as many field observations as possible to know which ones have the best tolerance for diseases. Feedback from the field will help our team position products for our growers’ success. The more we know about any diseases or other issues in fields the better we are able to make the correct recommendations to maximize yield and profitability. Please reach out with any questions or suggestions for improving our product lineup and placement.