Using weather observations from the North Carolina Environment and Climate Observing Network (ECONet), this tool can help determine the favorability for spraying herbicides that contain dicamba. While these assessments are specific to each ECONet station, they can provide guidance for surrounding locations.
Acceptable conditions for herbicide application are based on the instructions of popular chemical products as well as consultation with the Department of Crop and Soil Sciences at North Carolina State University. These conditions are as follows:
- No temperature inversion present, or temperatures constant or decreasing from 2 meters (approximately 6 feet) to 9 meters (approximately 27 feet) above ground level. This ensures that the spray droplets fall to crop levels and do not remain suspended in air.
- Wind speeds at 6 meters (approximately 18 feet) above ground between 3 and 10 mph. This ensures that the spray will not drift before it hits the intended crop. The low threshold is sometimes used as a proxy for a temperature inversion.
- Wind gusts at 6 meters above ground are less than 12 mph. Similar to wind speed, we want to make sure that the wind gusts are light enough for the herbicide application to hit their intended target.
In the panel below, the top left map indicates the overall suitability of Spray Conditions based on these three metrics. Conditions are Unfavorable for spraying if any of the three above conditions are not met. Use Caution indicates that conditions are near the thresholds for one or more categories and could be unfavorable at your specific site, depending on local differences in temperature and wind speed. Favorable indicates that conditions comfortbly meet all criteria for spraying. The other three maps on this page provide meteorological information to help users assess the suitability of conditions for spraying.
For more information about the intended usage, best practices, and safety information regarding applications of these chemicals, visit the NC Cotton Extension Portal or the NC Soybean Extension Portal.