07/10/25 When Heat Meets Humidity: Cercospora’s Perfect Storm
This is the sugar beet report, bringing you the latest information from NDSU throughout the sugar beet growing season. Unlike this time last year, which was hot and dry, we're in a hot and humid cycle, perfect conditions for cercospora leaf spot. Emma Burt, research agronomist for the MINN-DAK Farmers Cooperative, has the latest. Emma, give us an update of the sugar beet progress in your area.
Emma Burt:Yeah. Sure. Overall, I would say that our 2025 crop, appears to be in good shape and is progressing like we would expect it to. These wetter soil conditions that we've been experiencing as of late have given rise to a few of the root rots that are more endemic to our growing region. There's some small isolated pockets of Phantomiasis, Rhizoctonia, and even Fusarium that have started to develop across much of our districts. This is not uncommon though, especially considering the crop stage that we're at and, like I said, that warmer weather pattern that we've been experiencing.
Bruce Sundeen:Well, let's get to the meat. What's going on with Cercospora leaf spot?
Emma Burt:Cercospora, everybody's favorite. So right now, growers should be on or maybe even have already applied their second fungicide application for Cercospora. In talking to our egg staff and just being about in the plots and the nurseries myself, we're seeing Cercospora spots on leaves in the fields right now. And given the majority of our acres are planted to a CR plus variety, this is not something that we've seen at this time of year in a few years now. So that's pretty concerning for us. So with that being said, the fungicide applications, they really have to be a top priority for growers right now. Like I said, most should be applying their second application. If they haven't already applied it, that would be the second of six recommended sprays that we have lined up for them this year. With the possibility of a seventh, should September act like August.
Bruce Sundeen:Why is cercospora so prevalent right now?
Emma Burt:We are just really hitting the trifecta for cercospora. We've been really warm. We've been wet, and we've been very humid. And cercospora likes all of those things, so it's really starting to take off and it's just going to explode if we can't keep it in check with those fungicide applications.
Bruce Sundeen:What can producers do to control Cercospora?
Emma Burt:So they just wanna keep in mind, follow our recommended program, tank mix every single time. No mode of action should go out by itself. So we always wanna have at least two fungicides in the tank. Water volume is huge too. We wanna hit that minimum 20 gallons per acre if we can, and more would be great. And EBDCs, that's sort of our our token tank mix partner. It's effective. There's been absolutely no reported resistance to it since it was first registered way back in the nineteen forties. That really is our heavy hitter, and I know it's not the most fun to use, but it's incredibly effective.
Bruce Sundeen:So, Emma, where are you with sampling?
Emma Burt:Yeah. So next week, our ag staff will be going out, and they will be pulling samples. The first of three rounds of sampling that will be done. So next week, they will sample for population and root weight. And then the very August, they'll sample again, and they'll do population bruit weight, but then we'll have our quality lab up and running. So we'll also get a peek at percent sugar and percent purity. And then the last of those samples will be more towards the August around the third week there. Sampling is important because this is really the first time that we're getting a look at the potential of the crop, and we have an idea of what's there now. And then we have years and years of data so we can sort of chart what we would expect to be in the field at the end of the year.
Bruce Sundeen:Thanks, Emma. Our guest has been Emma Burt, research agronomist for the MINN-DAK Farmers Cooperative. This is the Sugar Beet Report, bringing you the latest information from NDSU throughout the sugar beet growing season.