Controlling Pesticide Applications

Understanding Pesticide Drift

When learning to apply pesticides, it is important to understand how to control your application. Pesticide educators often discuss controlling drops and drift (the movement of pesticides offsite if applications are not carefully monitored). Drift is not only a problem for agricultural or other operations that regularly use pesticides. Controlling pesticide drift is a homeowner and consumer responsibility as well. Even if you only occasionally use a pesticide to solve a pest problem, it is vital to control your application.

How Does Drift Occur?

Drift occurs when a pesticide moves away from the intended application site. There are two types of drift: particle drift and vapor drift. Particle drift occurs when fine pesticide spray particles move away from the target site through air currents. Particle drift can only occur during the pesticide application. Vapor drift occurs when gas or vapor from the pesticide application moves through air currents during or after the application.

Drift is more likely to occur with applications of liquid formulated pesticides. Liquid formulations exit the spray nozzle as drops, also referred to as droplets. Smaller droplets are more likely to drift, while larger droplets are more likely to settle within the target area. If the application equipment you are using permits adjustment of drop size, larger drops are recommended for pesticide applications.

Protecting Sensitive Areas

Drift is especially problematic in sensitive areas. These are usually areas associated with people, nontarget animals, and valuable plants. It is important to consider sensitive areas before making pesticide applications. Some examples of sensitive sites are:

• • • Homes or neighborhoods.

    • Office buildings/medical facilities.

    • School systems or daycare facilities.

    • Recreational areas or facilities.

    • Nontarget plants or animals.

    • Protected areas or wildlife refuges.

    • Beehives/areas with active pollinators.

Reducing the Potential for Drift

Adhering to certain guidelines when applying pesticides can help control drift and protect sensitive areas. Consumers and homeowners should follow these tips:

• • • Do everything possible to keep pesticides away from sensitive areas. For instance, do not apply pesticides on a windy day when they could drift into a sensitive area. Identify sensitive areas on and beyond your property and be mindful of them when using pesticides.

    • When possible, place sensitive areas away from sites where pesticide applications regularly occur. For example, if you plant a garden, locate it away from areas where children and pets may play. It may be as simple as moving your tomato container away from your rose bed when your roses need a pesticide application.

    • Consider alternatives to chemicals and become familiar with integrated pest management (IPM). IPM combines cultural, mechanical, physical, biological, and chemical control methods to deal with pest issues. With IPM, a chemical control method might be unnecessary, eliminating any drift concerns.

    • If you decide is to use a pesticide, select a product that is of minimal toxicity to nontarget species. Take time to make a proper selection and read the label. When applying a pesticide, make sure to keep the application on the target site.

    • Plan to spray when weather conditions are favorable. Wind (<2mph or >10mph), low humidity (<50%), and high temperatures (>82°F) are all unfavorable conditions for pesticide applications. Monitor your local weather conditions to select a favorable spray time.

    • To help prevent conflict, keep open lines of communication with your neighbors and your local Extension agent!

For More Information, Please Visit:

• Applying Pesticides Safely -- Virginia Cooperative Extension

• Introduction to Pesticide Drift -- Environmental Protection Agency

• Using Pesticides Safely and Correctly -- Pesticide Environmental Stewardship