This is the sugar beet report, bringing you the latest information from NDSU throughout the sugar beet growing season. Cercospora leaf spot in sugar beet is one of the big threats to the crop. Cercospora just took another step forward. Let's find out the latest with Eric Branch, NDSU and University of Minnesota extension sugar beet specialist. Eric, what's the latest with Cercospora leaf spot?

Yeah. So this past week, were multiple sites across the entire sugar beet growing region, Red River Valley here in North Dakota and Minnesota, where symptoms of Cercospora leaf spot were detected. Visible to the eye, these are those small circular lesions, gray or tan centers, little bit of a margin color to them. But at that point, we know the pathogen is working and infecting and doing its job at a scale we can see rather than just the DNA latent infection methods, which we've done earlier in the month. But at this point, the pathogen is creating lesions, and from those lesions, the Cercospora leaf spot fungus, Cercospora baticola, produces pseudostromata. And from these pseudostromata, spores are produced. And each spore has the chance to land on a new leaf and produce one more lesion. So hundreds of spores per lesion, and before we know it, the epidemic is out of control and can cause some significant crop loss. I do consider this a turning point in the season, Bruce, when symptoms have been detected.

Now that cercospora can be seen, does anything change for the producers?

Yeah, you know, it just drives home the point that preventative control is the best control. As a plant pathologist, you know, we say the disease cycle is exponential, And so it just keeps going up and up and up and becomes increasingly severe as the season goes on. Except adequate fungicides applied at the appropriate intervals, ten to fourteen days, maybe a tiny bit shorter if it's been rainy, can provide control, and we have lots of evidence to show that those strategies can be very successful.

Eric, what's the most common question farmers ask you this time of year?

Well, as I'm sitting here even in the July, what has been a concern for growers here in the region and Us extension folks is mixing fungicides and herbicides together in order to apply them both at the same time and save fuel, save time, save labor, to help protect the crop from two pests at once. Short answer, Bruce, it's easier said than done, and we don't typically recommend that. It's in my opinion, and a lot of the research that's been done focuses on one group of pests at a time. Either we're gonna control weeds or we're gonna control the fungus, the pathogens, and then come back, you know, three days later is kind of the recommended rule of thumb for applying those two different chemical groups. And my main concern is not only efficacy. Are these products going to provide the same level of control together as they would separately, but just crop safety too, you know. And we at Extension, we're not gonna make a recommendation unless we've got the numbers and the data to really support that. So for the time being, my answer has always been, you know, on the side of caution. We don't wanna see phytotoxicity symptoms, necrotic beet leaves, especially when the crop is young and vulnerable. So that's kind of been, in my opinion, a newer question, more interesting question, and more frequently this year. And I think just because the time scale has been compressed so much between the rains and the storms that the chance to actually get out in the field to make those applications has been shorter. That's what we'll be working on and thinking about going forward next year as well.

Thanks, Eric. Our guest has been Eric Branch, NDSU and University of Minnesota extension sugar beet specialist. This is the sugar beet report, bringing you the latest information from NDSU throughout the sugar beet growing season.