Help growers understand how they can minimize off-target movement

Retailers can help their customers feel more confident by offering tips to minimize pesticide drift. Growers can reduce drift by adopting good management practices and by choosing products that offer low volatility and limit physical drift.

Off-target application of pesticides can damage neighboring crops and may leave a grower and/or commercial applicator open to legal action and financial penalties. It also requires time to work through the off-target movement claims. As their neighbors plant susceptible crops – including grapes, tomatoes and cotton – growers need to pay close attention to ways of avoiding off-target movement. Retailers are in a great position to help them understand more about how and when it can occur and help them minimize incidents of drift.

How pesticides move   

Pesticides can move off-target in three ways: through particle drift, through vapor drift and via application equipment not properly cleaned. The most obvious form of drift is particle drift. This occurs during application when small droplets stay in the air long enough for air currents to move them away from targeted plants. With higher wind speeds, these particles can move a surprisingly long distance.

In addition to high winds, other environmental conditions can cause small droplets to move out of targeted fields. Temperature inversions can occur even when calm, low-wind conditions exist. According to Mitigating Pesticide Spray Drift, a University of Arkansas publication, temperature inversions involve increasing air temperatures with increasing height. Cooler, denser air settles below warmer, thinner air, preventing vertical mixing. This allows the cooler air containing pesticide particles to move horizontally into neighboring fields.

Remind growers to avoid applying pesticides when they suspect a temperature inversion. Inversions may occur when wind speeds are slower than 3 mph, often beginning a few hours before sunset on clear, calm evenings. They can be strongest just after sunrise after a clear, calm night. The presence of fog or dew is a strong indicator of a temperature inversion.

Promote low-volatility products

Vapor drift — also called volatility — involves movement of pesticide from plant or soil surface into the air. Every pesticide formulation has its own propensity for volatility. Weather can influence whether the product actually moves. The University of Arkansas publication suggests applicators select low-volatility formulations and adhere to all application recommendations on the product label to avoid vapor drift.

Pesticides can reach susceptible crops in a less-obvious way — through residue from a poorly cleaned sprayer tank. Retailers can help by reminding customers to clean tanks according to the product label between uses. Products with clear, easy-to-follow tank cleanout instructions can help growers avoid an accident.

The Enlist™ weed control system can help growers avoid all three potential herbicide movement issues listed above. Enlist Duo® herbicide is designed for use in Enlist crops. It combines glyphosate and new 2,4-D choline and features Colex-D® technology, which offers near-zero volatility and minimized potential for drift. In addition, the label for Enlist Duo herbicide describes the simple tank cleanout procedures, which involves a single rinse when the next field to be sprayed is glyphosate-tolerant corn or a triple-rinse with water if moving to any other crop.

Retailers who help growers realize ways to control off-target movement are providing a valuable service — one that will strengthen relationships and help make growers more successful.

For more information on on-target application and Enlist Duo herbicide, visit

®™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow. Enlist Duo herbicide is not yet registered for use on Enlist cotton. Enlist Duo is not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions. ©2016 Dow AgroSciences LLC