This is the sugar beet report, bringing you the latest information from NDSU throughout the sugar beet growing season. Growing sugar beet means you're familiar with the arch enemy, Cercospora leaf spot. To battle this devastating disease, research is key. Nate Wyatt, USDA research plant pathologist in the Sugar Beet and Potato Research Unit, has ongoing research. Nate, apparently, you're ganging up on cercospora. What kind of collaborative research are you doing?

So we have some really exciting research going on in collaboration between USDA and NDSU. One specific project we have is really getting dialed in on our understanding of the Cercospora leaf spot disease cycle, particularly research from my lab in collaboration with Doctor. C. Core at NDSU and Doctor. Branch at NDSU have been looking at trapping Cercospora spores and identifying the true start of Cercospora leaf spot infection in sugar beet fields using our molecular tools. And how we're using that is as a tool or a indicator of when we can start applying fungicides to really control that primary inoculum. So by targeting the actual start of infection, can really precisely time fungicide applications. And we're really happy that over the last now five years, that's been really consistent, and we've been able to target the June, July as really good spots to start applying those fungicides.

What about Cercospora in the remaining part of the season?

Now that we feel like we have a good grasp on the beginning of the season or the actual start of the infection, where we want to focus our research now is on the disease progression throughout the season and really focus on refining that disease forecasting model. So that's Cercospora leaf spot disease model. As of right now, it actually works pretty good as far as its predictability of symptom onset. However, there's a lot of parameters that we need to understand in order to be able to refine this model such as the impact of extended dry periods, understanding additional spore generating cycles, and also looking at the relative distribution of fungicide resistances across the year. In looking at those aspects, we're really hoping to dial in this risk model and that way we can more precisely recommend fungicide applications, particular chemistries that should work best. And really, you know, I keep saying dial in our fungicide usage for Cercospora leaf spot to best manage this disease.

Nate, how is research on fungicide resistance going?

Sure. So we have a really good foundation to build on when looking at fungicide resistance because Doctor. Gary Secor has been doing isolate collections to the tune of thousands of isolates every year dating back to 1997. And so we have this amazing historical record of the levels of fungicide resistance to any particular fungicide chemistry. And it's really cool because that timeline incorporates the introduction of new fungicide chemistries that didn't exist. And so we can see how it developed over the years and use that information to hopefully forward predict the relative durability of any new fungicide that comes onto the market for sugar beets. Now, where my lab got involved is in looking at the actual distribution of the mutations that lead to fungicide resistance and looking at cross resistance between different fungicide chemistries for Cercospora. And one of the really encouraging findings from that work is that very few of our Cercospora isolates that we've collected are capable of being resistant to multiple fungicides. And so even though it might seem like you have lots of fungicide resistance in a particular field, that multiple fungicide resistance is being contributed by different individuals. And this is a good reason to continue with tank mixing, to continue switching up your fungicide chemistries in your fungicide regimen. Because if you theoretically can tackle 50% of isolates with chemistry a, say it's a Triazole, and then you can come back later with a tin and get the remaining 50% by continuously changing up that obstacle for Cercospora, you're not allowing the pathogen to adapt and specialize towards one particular fungicide resistance. So the best practice is always going to be to keep your enemy guessing, and that's what we're trying to do with Cercospora as much as possible.

Thanks, Nate. Our guest has been Nate Wyatt, USDA research plant pathologist in the sugar beet and potato research unit. This is the sugar beet report, bringing you the latest information from NDSU throughout the sugar beet growing season.