Ag Notes

Nothing to do about Seedling Diseases in Soybean


Soybean seed treatments aren’t working at the moment and there’s nothing a farmer can do.

If you drive around much you’ll have noted some drown out areas in soybean fields, probably across the whole of the corn belt. Those are pretty easy to spot, but there are some areas that look like they’ve not been underwater - at least not for very long, if at all. They’re wilted back and showing signs of seedling diseases says University of Illinois Extension Plant Pathologist Nathan Kleczewski, "You must remember these soybeans have been in the ground for 30 or 40 days and seed treatments are going to only give us two to three weeks of protection.

Under perfect conditions your are going to see about three weeks of protection says the researcher, and we’re well past that point now. Kleczewski says while it is unusual at this point in the season, the Plant Clinic at the University of Illinois has been getting in samples of treated soybeans that are clearly suffering from seedling diseases, “f you think about the environment we had and the conditions we had immediately after planting. So, when we planted it was really warm and wet there for a while. So, you can imagine that initially this plant would have germinated from the seed and started to throw off roots. And then from here we are seeing from those initial roots, see how they are very white and stiff, this is because the outer cortex sloughed off. This is usually a sign of pythium infection and maybe there was also some rhizoctonia infection. So this canker you see here would be indicative of rhizoctonia.”

There is nothing to do at this point says Kleczewski. Spraying a fungicide on won’t do any good. If things dry out the plants may recover. Still there will be some stand loss, but not likely much yield impact.