By Scout Nelson
Minnesota sugar beet growers are preparing for the possible return of Cercospora leaf spot, a fungal disease that can reduce crop quality and lower farm income. The disease affects sugar beet leaves and can decrease the amount of sugar stored in the roots.
Joe Sullivan, a sugar beet farmer in Renville County, experienced major losses when the disease affected his fields last year. The infection reduced his yields by about one-third and created financial challenges for his farming operation. Sullivan explained that infected plants use stored energy to grow new leaves instead of building sugar in their roots.
Cercospora leaf spot develops when weather conditions create a favorable environment for the fungus. Ashok Chanda, associate professor and extension sugar beet pathologist at the University of Minnesota, explained that changing weather patterns with more storms, heat, and humidity can increase disease risks.
Chanda noted that recent growing seasons provided conditions that supported both strong sugar beet growth and disease development. “Historically, the years that we have higher disease are also really high yield for sugar beets,” said Chanda. “[Sugar beets] need temperature; they need moisture. The Cercospora thrives on the same conditions, so that's why you know when you have a huge crop, you have a huge risk for the disease as well.”
The current growing season is developing well, but continued heat and rainfall during July could increase the chance of disease spread. Farmers are encouraged to regularly check fields and take early action when symptoms appear.
Management practices can help reduce the impact of Cercospora leaf spot. These include applying recommended fungicides, improving crop rotation plans, and using cover crops when appropriate. However, experts note that there is no complete cure for the disease, making early detection and active management important.
Sullivan said USDA laboratories are testing sugar beet fields in his region to identify possible disease activity. He expects some fields may show signs of infection but believes early action can slow the spread.
“With the crop that we have, I'm sure we'll find spots by the first or second week of July,” said Sullivan. “If it doesn't stay as cool and not as humid, then it'll be better. But if you have hot and humid, it's just a matter of weeks that you're going to find some spots.”
Sullivan remained focused on protecting the crop through careful management. “We have a great crop coming up; it’s just a matter of being proactive on our management.”
Photo Credit: gettyimages-luiscarlosjimenezi
Categories: Minnesota, Crops, Sugar Beets, Weather