Bruce Sundeen: 00:00

This is the Sugar Beet Report, bringing you the latest information from NDSU throughout the sugar beet growing season. Today we're discussing some of the common soil borne diseases that affect sugar beet. Our guest is Dr. Ashok Chanda, Extension Sugar Beet Pathologist with the University of Minnesota Northwest Research and Outreach Center in Crookston, Minnesota. Ashok, since producers planted early this year, what does this mean for some of the common soil borne diseases?

Ashok Chanda: 00:27

Yes, Bruce. I think things are looking pretty good right now. You know, most of the beets were planted between, you know, 2nd and then 3rd week of April in the valley. You know, now some are, anywhere from 2 leaf stage to a little bit early. But the good news is the early planting really helps in faster emergence, you know, especially we got some moisture. Some of the soil borne diseases are not really favored by these cooler soil temperatures. But if you think about these diseases, we routinely deal with rhizoctonia, aphanomyces, and physiarum in some growing areas in the valley. But I think out of these 3, rhizoctonia is very widespread.

Bruce Sundeen: 01:08

Why is rhizoctonia such a common occurrence? And what can growers do to manage it?

Ashok Chanda: 01:14

So rhizoctonia is a bigger problem for us because, you know, it does not just infect sugar beets. It can infect corn, soybean, edible beans, you know, pretty much most of these crops that we grow in rotation with sugar beets. The only crops that are not affected by rhizoctonia are small grains such as wheat or barley. So anytime you have this, you know, you have really low levels of disease pressure for rhizoctonia. In the next couple of weeks, you know, as the beets are getting bigger, the best way to manage rhizoctonia is by applying a postemergence fungicide.

Ashok Chanda: 01:45

Now the recommendation is to apply a fungicide between 4 and 8 leaf application stage. If you have a field with severe history of rhizoctonia, it's better to do this early at 4 leaf stage. But if you have a field with, you know, moderate to low risk for rhizoctonia, you can do between 6 to 8 leaf stage. So this is going to help control rhizoctonia at this phase. And then it'll help later in the season.

Bruce Sundeen: 02:10

What about managing aphanomyces?

Ashok Chanda: 02:13

So for aphanomyces, again, we have excellent seed treatments and also some sugar beet varieties that have very good tolerance to do this for aphanomyces. But generally, every 3 to 4 years, you know, we can have some issues. But especially this year with early planting, it's not a big concern. But in some fields with history of aphanomyces, we can still expect, some root rot as we go later into the season. The factory waste line, they're to buy product from the sugar factories. It works very well if you apply 5 to 10 tons per acre.

Bruce Sundeen: 02:47

How can growers identify fusarium?

Ashok Chanda: 02:50

So we have some areas in our, the sugar beet growing region here that can be affected with severe fusarium. But generally, you know, when the seedlings are very small, you can see some kind of burn on the seedlings. It almost looks like an herbicide injury, but it's not caused by them. You know, the fusarium can be very similar. When the beets get a little bit bigger, the leaves turn yellow. You know, we call this as a chlorosis. The biggest signature for a fusarium, if you cut those roots, we can see actually dark lesions inside. You know, that just tells us that fisarium is colonizing those tissues.

Bruce Sundeen: 03:26

Is this year different from many other years?

Ashok Chanda: 03:28

So, again, I think with early planting and then cooler weather conditions that we have, I don't think fusarium is any big risk this year.

Bruce Sundeen: 03:36

You're offering sugar beet disease diagnosis again this year. How does it work?

Ashok Chanda: 03:41

So thanks to the Sugar Beet Research and Education Board. Again, this year, we got some funding from them. Any time you suspect something happening with the beets in the field, especially if you think that's a disease, please pull a sample and then send it to the Sugar Beet Pathology Lab at the Northwest Region Outreach Center in Crookston. And typically, in 2 to 3 days, we can get back to you to what's causing the particular disease on those beets.

Bruce Sundeen: 04:05

Thanks, Ashok. Our guest has been Dr. Ashok Chanda, extension sugar beet pathologist with the University of Minnesota Northwest Research and Outreach Center in Crookston, Minnesota. This is the Sugar Beet Report bringing you the latest information from NDSU throughout the sugar beet growing season.