Belchim USA: Growers Get TOUGH® on Herbicide-Resistant Weeds

The concept of the weed seed bank and the evolution of weed resistance over the years is requiring growers to think about herbicides differently. In the case of the former, it is an ever-present component of agriculture that centers on understanding, interpreting, and predicting seed germination. And when it comes to the latter, the weed spectrum has evolved beyond what it was in the early 90s and 2000s. Today, growers require a truly integrated weed management program that includes multiple modes of action (MOAs). In corn, this means adding to the “standard” glyphosate, HPPD, and atrazine post-emergence tank mix. Take, for example, a selective, contact herbicide like Belchim Crop Protection's TOUGH^® 5EC that synergizes HPPDs, enhances atrazine, and increases control of key broadleaf weeds that can impact yield, and combat weed resistance in both today and tomorrow’s crop.

TOUGH 5EC may be a familiar name to those growers who were in cornfields 30 years ago. Sold by Novartis/Syngenta primarily as a standalone product at the time, it was used to combat common broadleaf weeds impacting dryland corn. However, with the advancement of glyphosate-tolerant corn, many companies decided to move away from investing in post-emergence herbicides. That was then.

At the same time, popularity of HPPDs increased after repeated usage of ALS inhibitors, ‘Group 2’ herbicides, in the late 80’s and early 90’s. Accordingly, ALS resistant waterhemp became a common and widespread issue in cornfields and HPPD inhibitors became the answer to weeds that resisted glyphosate and other common herbicides in the 2000s. However, a decade later, even postemergence applications of HPPD herbicides mesotrione, topramezone, tembotrione and tolpyralate became less effective. 

Research published in 2014 highlighted how herbicide usage in the US increased from roughly 10% of the total area of cotton, maize, and wheat fields in 1950, to almost 99% in 1980. According to the study, the over-reliance on herbicides over the past several decades combined with the lack of preventative or other cultural practices, and sometimes the nature of the weed’s reproductive system itself (in the case of common waterhemp and palmer amaranth) resulted in the evolution and spread of herbicide-resistant weeds.

The Solution

Understanding that commonly used herbicides are no longer working on herbicide-resistant strains, and with the steady focus on equipping growers with more sustainable products that can survive an increasingly restrictive regulatory environment, Belchim Crop Protection USA realized that change was needed for both the crops and the growers to survive.

This led Belchim Crop Protection, headquartered in Belgium, to further reflect on and test the benefits of pyridate in the USA, a ‘Group 6’ herbicide with no known resistance, and ultimately to re-register TOUGH 5EC in the USA. Taking into consideration the challenges existing at that time (in 2015), Belchim Crop Protection used university trials to confirm the suspected and impactful increase in control that pyridate could provide, especially in resistant broadleaf weed populations. This time the focus was not on using pyridate as a stand-alone solution, but rather on how it could be used in combination with other impactful chemistries. In September of last year, the EPA officially granted approval for this fast-acting, post-emergent, contact herbicide for corn, as well as mint and chickpea. 

The Benefits of TOUGH 5EC

Growers can easily add TOUGH 5EC into their integrated weed management programs for post-emergent control of broadleaf weeds, applied up to the 8-leaf stage. TOUGH 5EC offers enhanced control of the most tough-to-kill weeds like common waterhemp and palmer amaranth that are no longer fully mitigated by today’s “go-to” chemistries. Both of these weeds can produce 100,000 to 400,000 seeds, even when competing with a crop. Their seeds are small (1-2mm) and are easily dispersed by wind, animals, livestock feed, and equipment. 

Let’s take a look at what that means from a sheer volume perspective. A post-emergence tank mix that provides 95% control will still allow 5% (let’s say 50 plants per acre) to escape. Based on this, the potential dispersion could be 20 million seeds per acre or 460 per square foot! Even just one plant can set into motion a chain reaction that takes years to overcome. Without total control, the weed seed bank proliferates, and tomorrow’s crop is affected by today’s problems in the field. 

TOUGH 5EC delivers a faster speed of kill due to its synergistic effect with HPPDs and ability to enhance the impact of atrazine. Not only does this control the weeds efficiently and effectively, but it also prolongs the use of HPPDs, even against resistant weed populations. Results of field trials Belchim USA has coordinated with major universities have demonstrated a 5% to 30% increase in control, even in herbicide-resistant populations. In collaboration with major universities across the cornbelt, Belchim USA demonstrated that a tank-mix combination of TOUGH 5EC, glyphosate, and mesotrione achieved 99% control eight days after application in glyphosate-resistant common waterhemp populations. Growers will benefit significantly from the addition of the active ingredient (pyridate) in TOUGH 5EC, making it a vital tool in the farming industry for years to come.

Those corn growers who utilize TOUGH 5EC in their integrated weed management programs give themselves the best chance for crop success by reducing the selection for herbicide resistant weeds and preventing their seeds from going into the weed seed bank. Today, Belchim USA has secured approval for use of TOUGH 5EC herbicide in corn, mint, and chickpeas, and continues to look to expand the label for us in additional crops, including soybeans. Together, we can get TOUGH on weeds!