Shawna Hubbard of Corteva Agriscience explains why 2,4-D inherently is less volatile than dicamba, making it easier to decrease volatility even more with the choline salt formulation. This conveys major advantages when it comes to tank-mix options that retain the near-zero volatility of 2,4-D choline, the active ingredient in Enlist™ herbicides.
Make your herbicide applications more successful by following the product label and using qualified nozzles at the optimal settings. Whether this is your first year using Enlist™ herbicides or you’ve applied it before, Andy Carriger, Enlist field specialist for Corteva Agriscience, shares expert advice on choosing nozzles to achieve more-effective applications.
“If you’re used to other technologies, like LibertyLink or dicamba systems, the nozzles are quite different than what we recommend with the Enlist system,” Carriger says. “We recommend a low-end of a coarse droplet range, somewhere in the 200- to 250-micron droplet size instead of a very large 500 micron or fine 100- to 125-micron size.”
He emphasizes the importance of hitting the droplet range, not only for a consistent droplet size, but also to achieve good coverage. In the midwest and plains geography, Carriger recommends using an AIXR nozzle when applying Enlist herbicides. It’s an air-inducted, extended-range nozzle that provides a consistent spray pattern with a 200-micron droplet size. The graphic below shows the differences in droplet size.
“If you've been using the dicamba system and you're used to ultra-coarse nozzles such as a TTI, you're going to want to change your nozzle setup when using the Enlist system,” Carriger says. “I use this analogy: It’s like you've been putting bowling ball-size droplets on the plants with your previous nozzle setup. Your coverage is going to be less than ideal for small weeds. You need ping pong-ball size droplets.”
The TTI nozzle is often used with the dicamba-tolerant weed control system and, although the TTI is qualified for use with Enlist herbicides, is not an ideal nozzle for coverage because of the very large droplet size. Carriger shows the difference in droplet size between the TTI and AIXR nozzle at 50 PSI in this video segment.
The AIXR nozzle reduces 50% of the fines with more consistent droplet size for better weed control. Both Enlist herbicides – Enlist One® and Enlist Duo® – feature 2,4-D choline with Colex-D® technology. Both herbicides offer the inherent near-zero volatility of 2,4-D choline and reduced physical drift potential due to the combination of Colex-D technology and qualified nozzles.
In this video segment, Carriger shows the difference in spray patterns when 2,4-D choline with Colex-D technology is applied through the AIXR nozzle.
When combined with qualified nozzles, 2,4-D choline with Colex-D technology in Enlist herbicides cuts drift by as much as 90% compared with a tank mix of traditional 2,4-D and glyphosate. A broad choice of qualified nozzles are available with Enlist herbicides, from different manufacturers in multiple sizes. Check the list to find the optimum set up for your goals of coverage and drift control.
Following label requirements and choosing an optimal nozzle and pressure combination will help take control of problem weeds. Talk with a local Corteva representative for more information on nozzles, spray pressure and how to make an effective herbicide application. To learn more, watch our YouTube channel or follow us at @EnlistOnline.
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:
“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.
Andy Carriger is an Enlist™ field specialist who serves as the in-field expert for the Enlist™ weed control system for Missouri and Kansas. Andy has many years of experience in crop protection with Dow AgroSciences and Corteva Agriscience. Carriger and other Enlist field specialists are experts in weed management, application technology and crop research.
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.