A weed resistance toolbox contains many different strategies, but when it comes to the herbicide option — the best tool needs to contain a chemistry with no known weed resistance on the target weeds, and it needs to be lethal on weeds the first time. The unique Group 4 mode of action in the Arylex suite of products, combined with other actives, is a key means to tackling resistant weeds.
“Arylex-based products are an excellent way to manage resistance as they stop seed production in the weeds they target,” says Dustin Leskosky, technical sales agronomist with Corteva Agriscience. “To manage resistant weeds you need to not only change up chemistry, you need to make sure there are no weed escapes when you apply your herbicide. Arylex does the job — taking one risk factor away in the potential for resistance development.”
Group 4 chemistries have been around since the 1960s and their effectiveness has stood the test of time. First introduced to farmers six years ago, the active ingredient in Arylex is innovative in the Group 4 family in that it is the first in a new structural class. It has proven effectiveness at managing weed biotypes that have shown resistance, including Group 2 ALS inhibitors and Group 9 glyphosates.
“One Group 4 isn’t the same as all other Group 4s,” says Leskosky. “The primary binding site on Arylex is different than other Group 4 subgroups. There are six different known binding sites for Group 4 chemistries. You can treat them as different keys that allow the herbicide to work within the plant. Arylex binds to a receptor protein called AFB5, which is a unique binding site for the Arylex active.”
Leskosky says that Arylex is effective against an extensive group of susceptible weeds including cleavers, stork’s bill, hemp-nettle, round-leaved mallow, wild buckwheat, and lamb’s quarters. It’s also strong on weeds usually controlled by Group 2 chemistry including narrow-leaved hawk’s beard, dandelion and smartweed.
He says Arylex is formulated as a low-dose herbicide with an application rate of just two grams per acre, making it an environmentally responsible choice. It’s effective across a wide range of climatic conditions and weed stages, offering growers increased application flexibility, and allowing them to get the most out of every spray day in the growing season. Arylex has also been shown to be very tank-mixable with other active ingredients, often having an additive effect.
“Convenience is something that growers have been asking for, especially as farms get larger and the number of acres they need to cover in a short period of time becomes more challenging,” says Kelly Bennett, Western Canada herbicides category leader with Corteva Agriscience. “When you throw herbicide-resistant weeds into the mix you need something that makes your herbicide decision-making simple. Arylex is easy to transport, simple to store and is a convenient tank-mix partner.”
Bennett says that one of the best ways to speed up the time it takes to get spraying completed is to reduce the downtime spent filling the sprayer. Low-volume products that mix quickly mean less time filling and more time spraying. He says the lower dose of Arylex means it also doesn’t take up much space for storage or transportation on the spray rig.
Finding an Arylex product that fits
“Corteva’s approach to weed management is to provide complete solutions,” says Bennett. “We have seven products that contain the Arylex active ingredient. They include a pre-seed herbicide for canola, called Prospect, that is a great resistance management tool when combined with glyphosate, delivering three overlapping modes of action on a number of key weeds. The same benefit is part of Paradigm PRE + glyphosate ahead of cereal crops. Also for wheat and barley growers, Arylex is a key active ingredient in several in-crop herbicides, elevating broadleaf weed control and resistance management to higher levels than previously available.”
The products that contain Arylex have each been developed with a different goal in mind. As part of their product family, Arylex works to reduce the risk of developing herbicide resistance and helps make sure each herbicide tackles the differing needs identified by farmers.
“We’ve combined Arylex in several in-crop cereal herbicides with either multiple modes of action or products with different Group 4 chemistries,” says Bennett. “This includes Exhilarate, Pixxaro, Cirpreme XC and a newly registered product, Prominex. This helps to extend how long weeds will take to develop resistance, making sure these products work longer. Group 4 products cannot be used in-crop on broadleaf crops so growers will automatically rotate from canola or pulse crops to a different mode of action in their wheat or barley fields.”
Pixxaro contains multiple Group 4 active ingredients which increase control and expand the list of weeds controlled while rotating to a different mode of action. Exhilarate contains Group 4 as well as Group 2 herbicides to control annual broadleaf weeds in wheat and barley, offering multi-mode-of-action (MMOA) control of key weeds. Cirpreme XC also offers MMOA and controls persistent annual and broadleaf weeds in wheat and barley. New this season, Prominex is another Group 4 mix that adds control of annual and perennial broadleaf weeds including Canada thistle and kochia. On its current label is control of 33 weeds and suppression of six others. Corteva hopes to expand that label in future years.
“Where growers have had a lot of trouble with problematic weeds in the black soil zone, Pixxaro and Prominex control a wide spectrum of those challenging weeds,” says Bennett. “This is particularly good where the weeds are resistant to other modes of action. With Arylex in the mix, these products are ideal for early weed removal and will still take on bigger weeds with excellent crop safety.”
Rezuvant XL and Rexade are two pre-packaged combinations from Corteva that contain Arylex and control both grass and broadleaf weeds. New this growing season, Rezuvant XL combines Arylex plus a second broadleaf active with Group 1 grass weed control for safe and flexible crop protection in barley or wheat. Its more robust formulation provides increased control of kochia, lamb’s quarters, hemp-nettle and wild buckwheat. Rexade is a combination of Group 2 grass control with Arylex active and 2,4-D for one-pass control of virtually all problem weeds for wheat and barley growers. What’s unique about this combination is that it can be applied at the two-leaf stage of wheat, unlike other combinations with 2,4-D ester, giving more flexibility for farmers to start removing weed competition earlier.
For pre-seed burnoff, Paradigm PRE combines Arylex with a Group 2 for overlapping control of annual and perennial broadleaf weed and grass weed control ahead of wheat and barley. Using a pre-seed product like Paradigm PRE helps to delay the onset of resistance and also helps manage existing resistant weed issues in a single application.
For canola growers, Prospect is the Arylex pre-seed option. It has Group 4 and Group 9 active ingredients and is especially effective on cleavers ahead of canola. It helps maintain glyphosate as an important herbicide going forward by taking down Group 9-resistant broadleaf weeds. It also cleans up a field from problematic weeds like flixweed and hemp-nettle, getting the crop off to a clean start.
“Canola is a high-value crop and resistant weeds are increasing so I encourage growers to treat it like their other crops and use multiple modes of action as a pre-seed burnoff to start the season right,” says Bennett. “Prospect with Arylex active helps to make sure we are keeping canola fields cleaner for higher yields, and also delays the development glyphosate resistant broadleaf weeds going forward.”
