Weed management is the ultimate game of offense in agriculture. Before glyphosate resistance, weeds used to be easier to manage. Growers could use multiple treatments of glyphosate to kill the weeds. Unfortunately, times have changed and glyphosate-resistant weeds have continued to spread. With the increased pressure from resistant weeds, extra efforts are needed. Growers had to start adding other post-emergence herbicides to glyphosate (e.g. Cobra, Flexstar, and other PPO chemistry) and include residual herbicides as part of their weed management programs. This has increased the cost per acre for weed control.
Today, 30 weed species have been confirmed to be resistant to glyphosate globally, with at least 14 of those in the United States. With continued reliance on a glyphosate-only program, additional resistant biotypes will likely develop.
Now, more than ever, it is important for growers to control resistant weeds and minimize the future impact of additional weed biotypes becoming resistant to herbicides.
Growers can help manage and control the spread of weeds by using a systems approach, including:
- Applying overlapping residual herbicides to maximize the effects of a successful weed management program; and
- Properly utilizing the new trait and herbicide technologies as they become approved and available for use.
Applying Residual Herbicides: To be as effective as possible in controlling weeds, growers should also continue to use a strong pre-emergence residual herbicide program. A successful residual herbicide program will go a long way in controlling the weed population, by giving the crop more time to get established with less pressure from developing weeds and will reduce the potential for weed resistance by not relying on a single post-emergence herbicide program.
Utilizing New Technology: The new dicamba trait and herbicide technologies have been approved. These herbicides will provide more effective weed control and help growers battle resistant weeds. For 2,4-D (Enlist Duo), the chemistry has been approved for soybeans, corn and cotton. The Enlist traits for cotton were launched in 2017. Corn recently received export approval from China and will launch for the 2018 season. Export approval for soybeans are still in process, but approval is anticipated in time for the 2018 season.
It is important to keep in mind that although the new herbicide technologies offer efficiency and flexibility, relying on a program of using only dicamba or 2,4-D will likely lead to the development of resistant biotypes. This is why growers and applicators need to be diligent in following proper application procedures to help them battle these weeds, and also to slow future resistance to the new herbicide technologies.
To help mitigate weed populations and lessen the potential for evolving weed resistance, new adjuvants, including the Elite Adjuvants by West Central, have been developed to work alongside these new herbicide technologies to increase the efficacy of the herbicide, reduce drift and increase on-target application.
This systems approach or combination of herbicide applications will be the best way for growers to ensure the most effective weed management programs.
In this video from our June 2016 LIFT Summit, Joe Sandbrink with West Central Distribution explains the importance of weed management and what is needed to ensure and maintain weed control.
From my perspective, weed management is a key thing and as I said earlier there’s 14 resistant weeds and two glyphosates. Growers are used to being able to use glyphosates on all of their acres and it worked very well for a long time, but that’s not the case anymore. Depending on where you’re at it can be a real problem, so that’s why these new technologies are going to be fantastic in helping growers to get control of those resistant weeds.
Now having said that, it’s not an easy button like it used to be. We’re still going to have to utilize the residual herbicides and systems approach to weed control. So, using residual and then using these new technologies and a combination is going to be the way to go. If we start relying on them as a sole component we’re going to start developing resistance to those technologies. So I think getting that message out of, “Hey these are great additions to our toolbox, but they’re not the silver bullet to our solution. It’s still going to take a systems approach to control.”