Thanks to an online registry of pesticide-sensitive areas around Nebraska, pesticide applicators now have a source to help locate these areas before spraying. According to Pierce Hansen, University of Nebraska-Lincoln Extension assistant and pesticide educator, sensitive areas might include vineyards, orchards, beehives, greenhouses and crops under certified organic production.
If your operation falls into the pesticide-sensitive category, you can add it to the registry to help protect your crops from land spray drift, Hansen told producers at the UNL Crop Production Clinic in Norfolk recently. Spray applicators can check the registry before spraying to help them avoid such areas.
"Scope it out before you make an application and use extra caution when you are making an application near one of these site," Hansen said.
Wind direction and velocity can affect the potential for spray drift. "Use wind to prevent drift to off-target areas," Hansen said. "Use different nozzle types. Fine drops may promote drift."
Too little or too much wind may cause more drift. Wind speeds of three to 10 miles per house are optimum for the least amount of potential drift. Winds greater than 10 mph offer high drift potential, but when winds are too light, it is also difficult to observe what direction the wind is coming from, Hansen said.
When temperatures are high, spray droplets will be small and the potential for drift is greater, he said. That is why there is normally greater drift when conditions are hot and dry. Severe drift can also occur under temperature inversion conditions, when cool air near the soil surface is trapped under a layer of warm air. Very little vertical mixing of the air occurs under these conditions, even with a breeze. Small spray droplets may fall very slowly, or be suspended in the air and carried miles away from the spray site by a light breeze. He added that understanding optimal spray conditions and consulting the Driftwatch website will decrease the chance of off-target drift.
Driftwatch is a multi-state project, administered by Purdue University's Department of Agricultural and Biological Engineering, with the Nebraska Department of Agriculture serving as data manager for the project.
The registry also covers Indiana, Minnesota, Michigan, Illinois, Wisconsin, Montana, Colorado and Missouri, allowing pesticide applicators to locate registered sites by using Google Maps interface, showing specific locations for pesticide-sensitive areas. You can learn more by visiting www.driftwatch.org.