What works today might not work tomorrow. This is especially applicable to those who manage industrial sites where total vegetation control is required, such as utility substations. Here, gradual overuse of certain herbicides is causing stubborn weeds like marestail, kochia and several amaranth species to slowly resist herbicides.
Although the introduction of new herbicides delivers a fresh start of sorts with renewed control, it’s only temporary if the same pattern of gradual overuse occurs, says Scott Flynn, field scientist with Corteva Agriscience™.
“When control issues begin, there’s a tendency with each treatment cycle to just increase the rate of the same herbicides in order to get the required level of control,” Flynn says. “It’s a short-term solution at best, because eventually the per-acre treatment rates and costs can’t be maintained. But more critically, this practice has been proven to give rise to resistance with many of the particularly tough weed species.”
Proper management makes all the difference
Flynn says the best solution is twofold. First, introduce new modes of action into your tank mixes, and second, maintain a consistent rotation of those mixes.
“Even the most effective bareground herbicides have a relatively short span of effectiveness without proper management,” Flynn says. “That means establishing a consistent rotation of bareground tank mixes that includes herbicides with unique modes of action — to both fight resistance and extend the effectiveness of current bareground herbicides.”
Herbicide resistance is not a new complication in total vegetation management. Repeated spraying of the same herbicides can result in the evolution of stubborn, resistant weeds. Flynn says the best way to halt that evolution is by introducing fresh chemistry into your tank rotations.
A good example of fresh chemistry is Cleantraxx® herbicide. Cleantraxx uses two novel modes of action to provide preemergence and postemergence control of more than 65 grass and broadleaf weeds, with up to six months of residual. Tank-mixing Cleantraxx with a combination of other chemistries with unique modes of action like Milestone® and Opensight® herbicides provides several new options for effective control in bareground situations.
“It’s also been established that rotating herbicide programs delivers improved weed control while using less herbicide over time,” Flynn says. “That’s beneficial to the environment, as well as to bottom lines, because you’re not having to continuously increase rates, which can positively impact long-term budgets.”
To get more information on herbicide resistance and its global impact, visit the International Survey of Herbicide Resistant Weeds at WeedScience.org. For additional resources and recommendations in total vegetation control, visit BetterBareground.com.
™®Trademarks of Dow AgroSciences, DuPont or Pioneer, and their affiliated companies or their respective owners. When treating areas in and around roadside or utility rights-of-way that are or will be grazed, hayed or planted to forage, important label precautions apply regarding harvesting hay from treated sites, using manure from animals grazing on treated areas or rotating the treated area to sensitive crops. See the product label for details. State restrictions on the sale and use of Garlon 4 Ultra and Milestone apply. Consult the label before purchase or use for full details. Vastlan 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. ©2019 Corteva