Haley Nabors

Haley Nabors is a herbicide trait field specialist and serves as the in-field expert for the Enlist weed control system in Texas, Oklahoma, New Mexico and southwestern Kansas. She is a graduate of Oklahoma State University with a bachelor’s degree in agricultural economics. Her area includes a large number of cotton growers as well as some corn and soybean acres. Herbicide trait field specialists are experts in weed management, application technology and crop research.

  • Southwest

  • Cotton

  • Palmer amaranth

  • Program approach to weed control


Avoid temperature inversions

Haley Nabors stresses that there must be a minimum wind speed of 3 mph when applying Enlist herbicides. This allows some stirring in the atmosphere and helps avoid temperature inversions.


Avoid Spraying During Temperature Inversion

A temperature inversion occurs when a layer of warm air covers a layer of cooler air and acts like a lid, preventing the cooler air from rising and dissipating into the upper atmosphere. 

During a temperature inversion, spray particles can become trapped in the warmer layer of air and stay suspended until the wind increases. Gases, then, can move off target into neighboring fields, lawns and gardens and may cause injury to susceptible crops. 

Calm winds, clear skies and long nights increases the likelihood of a temperature inversion occurring. 

Temperature inversions often form when:
- Wind speeds are 3 mph or less
- During late evening or early mornings when temperatures are within 5 degrees of the nighttime low
- Fog is visible during dawn or dusk.

“We want a light wind — 3 to 10 miles per hour — when making a herbicide application,” says Haley Nabors, herbicide trait field specialist. Within a temperature inversion, applied products can move great distances. “Furthermore, the direction the trapped air will move is unpredictable.” 

Watch for signs of a temperature inversion
Nabors says farmers applying herbicides and other crop protection products need to watch for common conditions that create temperature inversions. If these conditions occur, do not apply any herbicides until the temperature inversion clears and the environment is favorable for a successful, on-target application. 

“We tend to associate temperature inversions with early mornings or late afternoons, dawn or dusk,” Nabors says. “The traditional expectation is that we’ll see a fog hovering over the field during a temperature inversion.”

However, Nabors says in West Texas, New Mexico and other areas with low humidity, the telltale layer of fog may not develop. Therefore, there’s no visual signal of a temperature inversion. 

Technology helps farmers identify best application conditions
Farmers should monitor temperatures and check field conditions. If the temperature is within 5 degrees of the overnight low, check the wind speed and particle movement in the field. Use an anemometer to measure wind speed. If it’s less than 3 mph, do not apply herbicide.

“If you apply herbicide during a temperature inversion, the spray particles may never hit the intended surface,” Nabors says. This makes the application less effective for the crop. “If it doesn’t reach the weeds, you’re wasting your herbicide dollars.”

In addition, farmers run the risk of damaging susceptible plants in nearby fields, lawns and gardens. 

Applicators should continue to monitor conditions in the field throughout the herbicide application. Release smoke or powder to indicate particle movement. The smoke or powder should drift gently with the wind. If it gathers in a stationary, suspended cloud, that indicates a temperature inversion. Do not spray. 

Remember, a complete lack of wind is a warning. Do not apply herbicides. Wait until later in the day and check again for a more favorable application environment. 

Cotton Variety Selection and Field Planning Help Optimize Enlist Herbicide Applications

Farmers must consider many factors in placing new technologies on their operations. With strategic field planning, farmers can place herbicide-trait technologies so they can be more successful using the systems’ weed control components.

To get full value from the Enlist weed control system in cotton, farmers need to understand what other crops are in the area and know the prevailing wind direction. This helps them place Enlist cotton on acres where they can make successful Enlist herbicide applications according to the label. Farmers who planted Enlist cotton in 2018 were able to follow the label when applying Enlist herbicides, obtaining excellent weed control while avoiding drift issues.

“It’s best to use the Enlist technology in areas that are conducive for on-target application,” says Haley Nabors, new technologies specialist. “Don’t get yourself in a bind by planting these varieties on acres where you know it may be tough to apply the herbicide according to the label – avoid placement in the middle of surrounding adjacent susceptible non-Enlist cotton.”

Nabors suggests growers map out fields where they can make the best use of the Enlist™ weed control system. This may include planting a nonsusceptible crop – such as soybeans, sorghum, rice, peanuts or corn – downwind of Enlist cotton.

“Plant Enlist crops in fields where you have windows of opportunity to apply Enlist herbicides,” Nabors says. “Monitor conditions and spray on days when the weather is cooperating and the herbicides will not drift when you follow the label requirements.”

Whenever possible, growers should avoid planting susceptible crops downwind of Enlist cotton. But if you find yourself in that position later in the season, fully utilize the other herbicide tolerances in Enlist cotton.

“If you’re surrounded by susceptible crops — or the prevailing wind blows toward them — it will be difficult to find weather conditions that allow you to use Enlist herbicides,” she says. “If that’s the case, you can still use glufosinate and glyphosate for effective weed control on those acres.”

When selecting cottonseed with the best genetics, right maturity and needed agronomic traits, consider the value of herbicide traits that support multiple modes of action. All these benefits are available with PhytoGen® W3FE cottonseed featuring the Enlist cotton trait and WideStrike® 3 Insect Protection. These varieties allow growers to protect more yield potential on every acre.

Attention to field locations and some proactive planning can help cotton farmers get the greatest value from their PhytoGen cottonseed with the Enlist trait.