WAWG
By Dr. Xianming Chen
Based on the weather data of the November and December 2025, stripe rust in the 2024 wheat growing season is predicted to be in the range of severe epidemic level (40-60% yield loss on susceptible varieties). Using a set of forecast models based on this winter weather data so far (November and December 2024), highly susceptible winter wheat varieties are predicted to have potential yield losses in the range of 27 to 57% with an average of 41% caused by stripe rust in 2025. The predicted severe epidemic level is attributed to the relatively warm weather in these two months.
Based on the potential epidemic level, commercially grown varieties are predicted to have 0 to 29% yield losses depending upon the level of resistance or susceptibility of individual varieties. The next forecast will be made in early March based on the entire winter weather data. According to the current forecast, fields grown with moderately susceptible (MS, ratings 6 and 7) or susceptible (S, ratings 8 and 9) winter wheat varieties may need the early fungicide application at the time of herbicide application. Resistant (ratings 1 and 2) and moderately resistant (ratings 3 and 4) spring wheat varieties should be selected to plant, and variety with MS and S ratings (6 – 9) should be avoided.