GDD Maps

Weed and sugarbeet growth can change depending upon environmental conditions. Researchers at Michigan State University determined that applying micro-rates based on Growing Degree Days (GDD) can improve weed control and reduce sugarbeet injury compared to applying micro-rates based on calendar dates. Growing degree days in this case are based on air temperature. Begin accumulating GDD the day sugarbeets are planted. After the micro-rate application, reset GDDs to 0 and begin accumulating GDDs again. Research indicates that applying micro-rates at intervals of 225 GDDs provides the most consistent weed control and crop safety. However, the spray interval can be adjusted depending on weed population and soil properties. Numbers on map represent GDD accumulated from April 1, 2010.