Arylex™ Active Protects Sunflowers and Controls Ragweed

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They’re an inspiration to artists, a symbol of nations and an exuberant expression of nature’s beauty. With their huge, golden faces and tall stalks, sunflowers seem to have a special hold on our imaginations. Although they’re native to the Americas, sunflowers quickly became favorites of European explorers, who brought them back to their own continent. Czar Peter the Great is credited with popularizing their cultivation in Europe, where today they are a stunning addition to the landscape.

Sunflowers are not only beautiful, they’re a profitable crop. Global demand for sunflower oil remains high, and demand for sunflower seeds is growing in response to an expanding market for vegan and health-conscious foods. Sunflowers are also a sustainable crop to produce. They don’t require much fertilizer or water to flourish, and they’re beneficial to pollinator populations. Over the past few years, sunflower production in Europe has increased, as some farmers are opting to cultivate sunflowers in place of corn because of the lower input costs.

Weeds threaten yield and public health

Although we tend to picture sunflowers as tall and mighty, this crop is actually highly susceptible to weeds. Ambrosia artemisiifolia (common ragweed) is one of the most troublesome. A single ragweed plant can produce approximately 3,000 seeds which can remain viable for more than 10 years. By the time ragweed reaches flowering stage, it’s about one meter tall and competing intensely with sunflowers for nutrients, water and light. Terres Inovia (the French technical center for oilseed crops), found that with as few as 10 ragweed plants in a square meter, farmers can lose up to 300 kg in yield per hectare. Depending on the severity of infestation and the crop, ragweed can reduce potential yields by 20-70%.


The image on the left shows a field of sunflowers treated with Viballa™ herbicide with Arylex™ active. The picture on the right shows an untreated field with an infestation of ragweed.

Ragweed also has a major impact on public health because its pollen is extremely allergenic. A single ragweed plant can release more than a billion pollen grains which are capable of spreading on the wind in a 100-kilometer radius. Just five pollen grains per cubic meter of air is enough to trigger an allergic reaction in people. Researchers in the EU estimate human ragweed sensitization will more than double in the coming decades, due to massive spread of the weed and anticipated impacts from climate change.1 When factoring in both health and agricultural effects, the costs of ragweed in Europe are estimated to be in the hundreds of millions of euros. Farmers across Europe are encouraged to control noxious weeds, including ragweed, and some countries have implemented ragweed-specific regulations. Farmers who fail to keep ragweed under control can face fines or other economic consequences.


Ragweed pollen is a growing issue across Europe. Levels of human sensitization are expected to more than double in the coming decades.1

Flexible weed control, better sunflower management

As ragweed continues to spread across Europe and pose an increasing threat to both health and farm yields, it is also proving more difficult to control. Ragweed is increasingly resistant to commonly used herbicides, including ALS herbicides. Having a new option—and one that combats resistance issues—is more critical than ever for sunflower farmers.

Arylex™ active offers a new option to control ragweed. It works by regulating the growth of weeds but fits into a different structural class of chemistry than other herbicides. This means it provides a different mode of action, which is why it works on ragweed resistant to other herbicides. Arylex is applied early in the season to provide control of ragweed as well as other weeds, including Xanthium spinosum and Abutilon theophrasti, and herbicide-resistant species such as Chenopodium album.

One of the big benefits for farmers is that Arylex can be used very flexibly on the farm. Thanks to its unique chemical structure, Arylex has a very low use rate compared to other commonly used herbicides. It also degrades rapidly in soil and plant residues, which makes it a good choice for farmers looking to rotate crops or use cover cropping. Arylex remains effective in variable climatic conditions, so it works in both cool, wet spring weather and warm, dry spring conditions. Arylex can also be tank-mixed with other products.* This flexibility makes it very convenient for farmers to use a program approach on weeds and incorporate multiple modes of action, while also potentially making fewer trips through the field to save resources. Arylex can be used post-emergence on all sunflower hybrids, including conventional and herbicide-tolerant varieties (such as varieties tolerant to imazamax and tribenuron-methyl).

Clearing the way for better sunflower production

As sunflower crop production blossoms with possibilities, farmers need more flexibility in their sunflower management options. Controlling weeds is vital to helping farmers grow more of this valuable crop efficiently and sustainably. With fewer ragweed plants surviving to flower, farmers can protect their yields and reduce pollen in the air. Arylex lets farmers worry less about the damage weeds can do to their harvest and the impact of uncontrolled ragweed on the community’s health—something that lets us all breathe a sigh of relief.

Learn more about Arylex active


*Always read and follow label directions and use products in accordance with local regulatory guidelines.

1 Lake, Iain, Natalia R. Jones et al. “Climate Change and Future Pollen Allergy in Europe.” Environmental Health Perspective. 125, no. 3 (March 2017): 385–391.

Helianthex™ herbicide containing 68 g of Arylex™ active per liter and Viballa™ herbicide containing 3 g of Arylex per liter are registered for use in sunflower in Europe. Helianthex and Viballa are not approved for sale or use in all states or countries. Contact your local regulatory agency to determine if a product is registered for sale or use in your area. Always read and follow label directions.