To keep ahead of resistant weeds, growers need alternative chemistries that have not developed resistance, and also products that are effective so that weeds are eliminated the first time. Arylex’s unique Group 4 active ingredient is an important addition to the resistance management toolbox.
“Seven of our products contact the Arylex active ingredient,” says Kelly Bennett, Western Canada herbicides category leader with Corteva Agriscience. “In the fight against herbicide resistance, Arylex active is included in two pre-seed products — one for canola and one for cereal crops — plus in-crop cereal herbicides to meet the various needs of wheat and barley growers. It’s a workhorse of an active ingredient that, as part of a product solution, will take down broadleaf weeds that cause problems for growers in the black soil zone.”
Bennett says Arylex offers improved broadleaf weed control over others in its same chemical group. While Group 4 broadleaf herbicides have been well known to farmers for half a century, not all Group 4s perform the same. The active ingredient in Arylex is innovative in that it is the first in a new structural class of synthetic auxin herbicides with a slightly different binding site. It’s also specifically effective in managing weed biotypes that show resistance to other modes of action such as Group 2 ALS inhibitors.
“Arylex works on weeds that are sometimes a little harder to kill, including those that are resistant to a Group 2 mode of action,” says Mark Johns, technical sales agronomist with Corteva Agriscience. “And with many of the products that contain Arylex you are using overlapping modes of action which helps to delay the development of resistance to a single chemistry.”
First introduced to growers in 2015, Arylex is a low-dose herbicide with a lower application rate that makes it an environmentally responsible choice. It’s effective across a wide range of climatic conditions and weed stages offering growers increased application flexibility.
“As farms get larger, keeping things simple and convenient is important to growers,” says Bennett. “This product makes herbicide decision-making simple. They can just scout once and go. The smaller packaging is easier to transport and store and it makes sprayer loading and mixing more efficient. Farmers are able to get the most out of every spray day and know that the Arylex-based products will be effective against a wide spectrum of broadleaf weeds across different weed and crop stages.”
In terms of grass tank mixes, Bennett cautions growers to always respect the precautions of the most restrictive tank-mix partner. Arylex active products work under a wider range of climatic conditions, which means farmers won’t need to worry about broadleaf weed control. The farmer can then make the go or no-go decision to spray based only on the grass herbicide. Using an Arylex active product means growers will face fewer delays, which is especially important to those with lots of acres to cover. The added advantage of a wide window of application for weeds and crop also benefits spraying logistics because the weeds or crop are seldom ever “out of stage”, allowing farmers to spray on their schedule.
Managing resistance with multiple chemistries
Part of Corteva’s product development objective is to offer multiple solutions to meet the varying needs of farmers in Western Canada. Arylex is never sold as a standalone product. It’s one key ingredient in a family of products that tackle the needs identified by their customers, with the added benefit of effectively contributing to weed resistance management.
“Arylex is contained in several in-crop products with either multiple modes of action or several versions of products from the same chemical Group,” says Bennett. This includes Exhilarate, Pixxaro, Cirpreme XC and a newly registered product, Prominex. Proper herbicide rotation and the use of multi-mode of action products help to extend how long weeds will take to develop resistance, making sure these products work longer. Arylex is a Group 4 product which cannot be used in-crop on broadleaf crops, so that automatically affects how growers rotate with this chemistry.”
Exhilarate contains Group 4 as well as Group 2 herbicides to control annual broadleaf weeds in wheat and barley. Pixxaro utilizes three Group 4 active ingredients to expand the list of weeds controlled while making it an excellent choice when trying to rotate chemical groups. Cirpreme XC is another mix of Group 4 and Group 2 that uses different modes of action to control persistent annual and perennial broadleaf weeds in wheat and barley. Prominex is a new addition to the Arylex suite and is another Group 4 mix that adds increased control of kochia and several other annual broadleaf weeds, plus Canada thistle. It also controls 33 other weeds and suppresses six more. Corteva hopes to expand the label of Prominex even further in the future.
“Pixxaro and Prominex control a spectrum of weeds in the black soil zones that growers have had a lot of trouble within the past,” says Johns. “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 if application gets delayed due to weather.”
Corteva also has two pre-packed tank mixes that contain Arylex. Rezuvant XL, also new this year, combines Arylex with Group 1 grass weed control for safe and flexible crop protection in barley. Its more robust formation provides increased control of kochia, lamb’s quarters, hemp-nettle and wild buckwheat. Rexade is a combination of Group 2 grass control, Arylex and 2,4-D for one-pass control of virtually all problem weeds for wheat growers. This is a very unique combination because it can be applied at the two-leaf stage of wheat, despite having 2,4-D Ester in the mix, giving farmers greater flexibility to start removing weed competition earlier.
In terms of pre-seed weed control Paradigm PRE tank-mixed with any glyphosate, combines Arylex with a Group 2 for overlapping control of annual broadleaf weeds plus grassy weed control ahead of wheat, barley and oats. “By using pre-seed product like Paradigm PRE with glyphosate you are delaying the onset of resistance and managing existing resistance issues all in a single application,” says Johns. “It’s a great option for growers who are covering a lot of acres and are fighting against the clock, and it also uses a lot less water than other pre-seed options.”
Prospect is the other Arylex pre-seed option and is the only Arylex product for canola growers. Combined with glyphosate, it has Group 4, Group 14 and Group 9 active ingredients and is especially effective on cleavers ahead of canola. By cleaning up a field from problematic weeds like flixweed and hemp-nettle on the first try and adding multi-mode of action broadleaf weed control it helps maintain glyphosate as an effective management tool going forward.
“It is interesting to me that it is very common for growers to use pre-seed products with different active ingredients plus glyphosate ahead of their cereal crops but it is less common in front of canola,” says Bennett. “Canola is a high-value crop and the benefits of pre-seed weed control for top-yielding crops is well known. Also, glyphosate is a critical tool and resistant weeds are increasing. The use of overlapping modes of action will keep glyphosate effective for a lot longer.”