For most of February and March, Alan York made the rounds across North Carolina delivering training for farmers and others who want to apply the new auxin herbicides on cotton and soybeans.
More than 2,600 farmers and other applicators have attended the 27 mandatory training sessions as of early March. “You really draw a big crowd for a meeting when you’re required to attend,” York said at the auxin training session in Clinton. York is a weed specialist and William Neal Reynolds distinguished professor of Crop Science at North Carolina State University
York said a total of 38 training sessions are planned across the state and more than 3,000 people are expected by the time training is completed. Of those who completed the mandatory training, 82 percent have been growers with the remainder including dealers, consultants and applicators.
The North Carolina Department of Agriculture and Consumer Services required the mandatory training session for applicators as part of a 24(c) special local need label for all products containing 2,4-D or dicamba to be applied on Xtend or Enlist cotton or soybean.
York said a key goal of the training is to help avoid the drift issues that occurred across the Mid-South last year and garnered negative national publicity. “EPA made it very clear that they are not going to stand for any more of that,” he said.
Registration for the new dicamba products is temporary, for two years. York said EPA can choose not to extend the registrations if there is a great deal of off-target applications of the herbicides.
“We need every tool we got. We would like to be able to keep these tools available to us. We have to demonstrate that we can use them responsibly,” York said.
The goal is to have no problems with off-target drift and zero incidents. “Obviously, we’re not going to make that goal. Somebody is going to screw up, but we want to keep those screw-ups to a minimum,” he said.
In the training, York noted that any compound can drift. “You can spray plain water and it will drift. What is different here is the level of sensitivity of other crops to these new compounds versus the products we are commonly used to spraying,” he said.
In essence, any broadleaf crop that doesn’t contain the Enlist (2,4-D) or Xtend (dicamba) trait is sensitive, with some crops extremely sensitive. York notes that North Carolina is a very diverse crop producing state with many high-value crops intermingled with cotton and soybeans.
“If someone is growing peppers in your neighborhood, you don’t want to be responsible for taking out those peppers,” York said. Cucumbers, cantaloupes, watermelons, garden beans, sweet potatoes and tobacco are all extremely sensitive to auxin herbicides.
York said he expects damage to home gardens from off-target applications will be the No. 1 complaint in North Carolina.
A number of things can impact spray drift, including the type of nozzle, the pressure you’re running, sprayer speed and boom height. The goal is to create very large droplets that won’t drift as far as small droplets.
Wind speed is critical and the 24(c) labels call for a maximum wind speed of 10 miles per hour in North Carolina. In addition, there is a minimum wind speed of 3 miles per hour due to the fact that light winds are unpredictable and variable in direction.
“A second reason is there is a greater risk of thermal inversions on calm mornings or late in the afternoon,” York added. “Thermal inversions are a layer of warm air trapped between two cooler layers. The inversion acts as a ceiling, preventing normal dispersion and dilution of fine droplets or vapors into the upper atmosphere. Thermal inversions will go away once you get some wind which is why there is the 3 miles per hour minimum wind speed.”
As for boom height, the XtendiMax and Engenia labels call for a maximum 24 inches above the canopy. The Enlist Duo label doesn’t have a minimum boom height, but says to follow the nozzle manufacturer guidelines.
One area that has created confusion is the requirement for buffer areas around the dicamba or 2,4-D tolerant crops.
“I’m convinced that a committee came up with this and wrote the regulations because no one individual could make it so confusing,” York said. “All of these auxin herbicides are going to have a downwind no-spray buffer between where you make the application and sensitive areas.”
York said the confusion comes in on the definition of a sensitive area. A sensitive area can be interpreted in a number of ways.
“We asked EPA what a sensitive area is and they said ‘we can’t tell you that. We can tell you what is not a sensitive area.’ In their mind it is four things and they will all be on the labels: roads, fields planted to a tolerant crop such as corn; fields that you’re getting ready to plant; and areas covered by the footprint of manmade structures.”
York said he interprets EPA to mean that a sensitive area is the habitat of a threatened or endangered species, which includes woods, hedgerows around the field and any kind of water body adjacent to the field. The auxin labels also make it clear not to spray when the wind is blowing toward a sensitive crop.
York believes drift complaints will be at a minimum this year if applicators follow the guidelines to avoid off-target drift and use common sense.
“I think there are lots of places in North Carolina where we can use this technology with no problems,” York emphasized. “But common sense says there are some places we shouldn’t use it. If I have a soybean field surrounded by tobacco on three sides, I don’t want to use it there.”
Deciding when to spray is vital; monitoring wind speed and wind direction is a must. “On some days I should be able to spray and on other days I can’t depending on the wind,” he said.
York encourages farmers to remember this rule of thumb: “if it isn’t your crop, and you can’t afford to buy it, don’t spray that day.”