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Improving lives by solving problems in agriculture and the environment

EU fights back with CABI against invasive Ragweed

EU fights back with CABI against invasive Ragweed

Known commonly as ragweed, Ambrosia artemisiifolia now costs the European economy an estimated €4.5 billion a year, affecting the quality of life of millions of people. In the first collaborative research effort of its kind on the continent, thirty-three EU countries are banning together to fight back against ragweed, setting a new model for joint- scientific endeavor, and raising awareness about solutions for invasive species control.

The SMARTER COST-Action, initiated by Professor Heinz Müller-Schärer of University of Fribourg, Switzerland, and Dr Urs Schaffner of the Centre for Agricultural Biosciences International (CABI), will bring together interdisciplinary experts from the biosciences, health care, economics and ecology on a 4-year research mission: to find sustainable strategies to control this noxious aeroallergen.

As Prof Müller-Schärer notes, “the goal of this Action is to develop habitat-specific management recommendations against ragweed across Europe, setting a model system for the sustainable management of invasive alien plants of European-wide interest.”

Originally transported from North America, ragweed has become a flagship alien species in Europe, causing serious health issues for humans including asthma and seasonal allergic rhinitis. It is estimated that half of all asthma attacks are triggered by ragweed in the regions where it has spread. With climate change, the reach of ragweed is set to increase year on year, recently becoming prominent in the UK, Hungary and as far east as Japan.

Central to this mission will be innovative methods of biological control. Here, ecologists use ragweed’s natural enemies to stop the spread of the invasive weed, protecting habitats and ecosystems as well as regional agricultural production. With a proven track record controlling ragweed in Australia, biocontrol is the most promising approach for a sustainable, long-term solution.

“Controlling invasive plants with the help of their natural enemies is probably the most important sustainable management approach globally,” adds CABI’s Dr Urs Schaffner who chairs the COST Action working group on biocontrol. “And yet, it is still a surprisingly underestimated approach in Europe.”

While herbicides and mechanical controls like mowing are also currently applied to mitigate ragweed in the short term, this Action lays the ground work for sustainable biocontrol of ragweed, assessing all social, environmental and economic layers of this approach prior to meeting the standards for testing and release of new pests by European regulatory bodies.

The COST Action against ragweed will propose a step-by-step plan for loosening Ragweed’s grip on the continent and pave the way for future joint research for the common good. “An invasive alien species knows no borders,” comments CABI’s Dr Schaffner. “It is this kind of landmark collaboration that will strengthen linkages within the scientific community, to bring quality results for the people and ecosystems of Europe.”


University of Fribourg:
Prof. Dr. Heinz Müller-Schärer
tel: + (41) (0) 26-300 88 35/50

Urs Schaffner, Head of Ecosystems Management, CABI Switzerland
tel: +41 (0)32 4214877

Julia Dennis, Communications Manager, CABI Switzerland
tel: +44 (0) 1491 829 468
For more information about CABI, visit

Notes for editors:

About SMARTER COST Action The SMARTER project focuses on the control of ragweed, or ambrosia, but in addition pursues the larger goal of developing a mode of action for the mitigation of other invasive plants and to propose the transnational and interdisciplinary basis necessary for future control actions against harmful, invasive organisms. The SMARTER project will last 4 years; it consists of several working groups, allows for exchange of researchers and students, and organizes summer schools, workshops and stakeholder meetings, besides the various management meetings.

More information is available at:



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