Rhizoctonia root rot is a serious disease problem in several sugarbeet-growing regions, with the result sometimes being dramatic — and expensive — reductions in tonnage and quality. Low levels of infection can easily cause yield losses in excess of a ton per acre, while high infection levels can cut yields by more than 10 tons per acre. The quality of surviving beets can also be impacted, sometimes resulting in significant losses in recoverable sugar.
Michigan Sugar Company has a goal to improve beet quality by increasing the co-op’s average sugar content to 19%. This goal is achievable, but it will take increased management and use of higher sugar varieties.
Many of our new varieties have a high tonnage and sugar potential; but several likewise are very susceptible to Cercospora leafspot and Rhizoctonia. Left unchecked, both diseases can greatly affect yield and quality. By using the BeetCast leafspot prediction model and appropriate fungicides, growers are doing an excellent job of minimizing the impact of Cercospora leafspot. While Rhizoctonia is more difficult to manage, we also have made great strides in reducing its effect on yield and quality
Don Lilleboe is editor of 'The Sugarbeet Grower' and 'Gilmore Sugar Manual.'