This is the Sugarbeet Report, bringing you the latest information from NDSU throughout the sugar beet growing season. We've had plenty of hot and dry weather, exactly what Cercospora leaf spot doesn't like. Does this change any sugar beet practices? Providing guidance is Ashok Chanda, extension sugar beet pathologist with the University of Minnesota and Northwest Research and Outreach Center in Crookston, Minnesota. Ashok, with all the hot and dry conditions, is Cercospora leaf spot still a concern for this growing season?

Yes, Bruce. I think we are breaking some records here. This is our, least fourth spell this season having 90 plus degrees. It's certainly warm and dry. It's not really conducive for Cercospora, but what we have to keep in mind is our nighttime temperatures are still about 60 degrees, which is perfect for Cercospora. And also, the canopies will have enough dew, which is sufficient for those Cercospora spores to germinate and start infection. Right? Again, if you think back on 2022, you know, we were dry in the first half of the season, but once we started getting rain in August and September, we got really severe outbreaks of Cercospora from the second half of the season. It's just been only, you know, about four weeks. Right? We still have eight to nine weeks before we harvest the beet, so we still have a long season ahead of us.

Should growers do anything differently to manage Cercospora?

Our growers are doing an excellent job in managing Cercospora leaf spot, especially this season. We had two severe Cercospora years, 2024 and 2025, back to back, which means that we have a ton of dormant Anastrocospora in the fields, again, with all the wind and soil blowing everywhere. So all of this inoculum is actually spread out, which was evident in early July when we saw those first spots on most of the fields, right? So we know that Cercospora kind of established at a kind of low levels at the beginning of the season and it's kind of staying low. I think one important aspect is most of the growers started applying fungicides in third week of June. Based on the grower records for American crystal, those are the applications that gave the best return on investment. Number two, we're using several different modes of action for fungicides. We're doing tank mixing, basically a systemic and a contact fungicide in every application. And most growers are, you know, following that about twelve day intervals. So now it's dry, which means that now we don't have a wash off of the fungicide. But remember that fungicides can degrade naturally over time, especially, you know, the UV rays can break them down as well. But what you can do is since it's dry and it's not really conducive, you know, you can extend those NOLs for another four to five days depending on where you're located. But stay the course. Right? Our goal is to delay the Cercospora infection as long as possible so that when we harvest those beets, are only having few spots here and there, right? Again, we cannot completely eliminate the disease, but we just want delay the establishment of disease in the canopy.

Ashok, what about the Sugarbeet Disease Diagnostic Service?

Yes, Bruce. We are again offering the Sugarbeet Disease Diagnostic Service to the growers this year, and thanks to the Sugarbeet Research and Education Board for funding this work. And it's extremely important for us to know what's killing sugarbeets in the field, you know, whether it's a root rot or a foliar pathogens. Right? If we don't know what we're dealing with, how are you gonna come up with a good management plan? If you suspect any problems in the field, please talk to your agriculturist. Typically, we get back with the results within two to three days, and then they can pull the samples and send it to our Sugarbeet Pathology Lab at Northwest Research and Outreach Center on the University of Minnesota Crookston campus. So please utilize this service.

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