Soybean Cyst Nematode and Sudden Death Syndrome have been two of the leading causes of soybean yield loss for years. But how does Red Crown Rot, a newer and rising disease threat, relate to SCN and SDS?
“Sudden Death Syndrome is a disease that gets in your soybean crop early in the season,” says Matt Geiger, an agronomic service representative with Syngenta. “You don’t often see expressions of the disease until the late reproductive stages, even though the infection happened months and months ago and that causes a sudden death. You see this leaf scorch late in the season, and it can wipe the plants out pretty rapidly because it makes them shut down. Once you see this foliar leaf scorch late in the season, the pods won’t fill all the way. You might abort some pods toward the top of the plant as well. So, Red Crown Rot, being what I would call its nastier cousin, is very similar to this in that it also gets in the plant early in the season and doesn’t express itself until late as well with this foliar leaf scorch. You get the question, ‘Oh, can I spray a fungicide to help me with this?’ And you know, unfortunately, it’s too late for both of those pathogens. You need to control both of those with a seed treatment. You want to prevent them from getting in the plants when they’re young.”
The challenge is distinguishing between Red Crown Rot and SDS because the symptoms are similar.
“It seems, at least in the geography that I cover in Southern Illinois towards Central Illinois, is Red Crown Rot is more of a predictable disease, and what I mean by that is it doesn’t seem like the conditions need to be as specific as they do with SDS. It seems like it can show up, almost no matter what, in fields where you have a high inoculum load. So, they’re diseases to be on the watch out for. They look a lot alike. You need to look at the roots late-season, if you want to try and identify between the two, because, at face value, you think you just have SDS because the foliar scorch looks very similar.”
“This is a disease that’s definitely on the rise,” says Dr. Carl Bradley from the University of Kentucky. “It’s causing some severe yield losses to farmers. I’ve walked fields that look terrible because of Red Crown Rot, but Soybean Cyst Nematode does interact with this disease, and so what’s been shown in work at LSU many years ago is when you’ve got both pathogens together, the Red Crown Rot symptoms are much worse compared to if it was only the Red Crown Rot pathogen that was present. If you just have some soil-borne pathogens by themselves, they’re going to cause yield loss. But if you have Soybean Cyst Nematode in that field as well, that yield loss and symptoms of the other disease is going to be magnified.”
Growers have a solid option to protect against SCN, SDS, and RCR.
“We’ve got a product that’s done all in one, and it’s called Saltro® Fungicide seed treatment,” Geiger explains. “It’ll give you protection for SDS, SCN, and RCR. So, it’s a very good product, and it’s also very safe on the soybeans. It has some plant-health benefits as well, so you can see bigger roots with this product as well, and so that’s kind of the all-in-one product that we recommend. We have a Two Double-E label for Red Crown Rot for a few states. So, what you can do is run a higher rate, and you can get suppression of Red Crown Rot. It’s not labeled for full control, but it will suppress the disease, so based on what that means, it will delay the leaf scorch symptoms.”
To learn more about Saltro, visit WhySaltro.com. Always read and follow label instructions.
Source: NAFB News Service
