Content by Philip Rozeboom
Dicamba-Resistant Kochia Can Likely Be Found Across South Dakota
Kochia populations collected across South Dakota have been subjected to an herbicide effectiveness screen, where a treatment of dicamba was applied and some kochia plants exhibited survival and regrowth after treatment.
Alfalfa Weevil Activity Prediction Update: May 29, 2025
The lowest calculated degree days in South Dakota indicate that fourth instar larvae should be active, while the highest calculated degree days suggest that pupation is occurring in the field.
South Dakota Overwintering Bean Leaf Beetle Predicted Mortality: 2024-2025
Each year we evaluate the overwintering success of bean leaf beetles in South Dakota. For adult bean leaf beetles that successfully overwintered, emergence will begin in the spring and they will move into soybean fields.
Wind and Rain May Have Delayed Preemergence Herbicide Application: What Now?
With recent winds and rain, preemergence herbicide applications may be further delayed. Scouting to determine if crops and/or weeds have emerged is critical to ensure effective and safe application of preemergence herbicides.
Alfalfa Weevils Are Active in Some Parts of South Dakota
Degree day accumulations indicate that alfalfa weevil larvae should be active throughout South Dakota.
Alfalfa Weevil Activity Prediction Update: May 22, 2025
Degree day accumulations for alfalfa weevil larvae indicate that third to fourth instar larvae should be active in fields throughout South Dakota.
Dry Conditions May Hinder the Performance of Recently Applied Preemergence Herbicides
If a preemergence herbicide does not receive an activating rainfall, generally 0.5 to 1 inch of rain, many weeds will emerge, as the herbicide remains on the soil surface.
Leafy spurge has germinated and is growing rapidly in South Dakota: Scout carefully!
Leafy spurge can reduce the value and productivity of pasture and displace desirable vegetation. Now is the time to scout for infestations to determine which management tactics will be most effective.
South Dakota Grasshopper Prediction for 2025
In 2025, it is likely that grasshopper populations will once again reach levels capable of causing issues in some areas of the state. Scouting should begin shortly after planting in areas where they were problematic in 2024 and continue throughout the growing season.
Saflufenacil-Resistant Kochia Confirmed in South Dakota
Saflufenacil is an herbicide that can be applied at a burndown timing before most South Dakota crops to effectively manage kochia. However, overreliance on saflufenacil has selected for resistant kochia in our region.