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A new herbicide option for controlling resistant blackgrass

Certis announce their new herbicide products, Sunfire and System50, will be available this autumn to give cereal growers much needed options to help control the key grasses (especially resistant blackgrass and annual meadow grass).

Certis announce their new herbicide products, Sunfire and System50, will be available this autumn to give cereal growers much needed options to help control the key grasses (especially resistant blackgrass and annual meadow grass).

Certis' arable product manager Inez Cornell explains, Sunfire and System 50 contain a unique straight formulation of 500g/l flufenacet.

"Flufenacet has been available in mixture products for a number of years, however, it has not been available on its own until now," she says. "Making flufenacet available as a straight product, Sunfire and System 50, will give growers and advisers more flexibility to create bespoke programmes for each field on the farm. With no new active ingredients on the horizon, Sunfire and System 50 will give growers a brand new tool for the fight against blackgrass."

Blackgrass resistance is an increasing problem in Europe, with more than ten countries reporting problems controlling blackgrass. "Because every plant has the potential to produce up to 2000 seeds, minimising plant survival and seed return is critical," explains Inez.

"Control of blackgrass must be approached as an overall strategy, using every tool in the box - rotation, ploughing, delayed drilling, spring cropping and competitive varieties alongside herbicide options." 

Dr. Stephen Moss has been studying resistant blackgrass for more than thirty years and agrees that it's absolutely critical for growers to get the best out of the existing herbicides we have available.

"Resistance is present on virtually every farm in the UK where herbicides are used to control blackgrass. In a non-random blackgrass survey conducted in 2013, 98% of blackgrass populations showed resistance to at least one herbicide," says Dr. Moss.

"Although we have a good range of herbicides available for grass weed control, there is also some degree of cross-resistance to many of them, so there isn't a simple solution to developing an effective herbicide programme," he adds.

The results of research show the overall trend is one of increasing herbicide resistance in post-emergence herbicides, with the efficacy of the ALS inhibitors (sulfonyl ureas) and ACCase inhibitors (fops and dims) showing the steepest decline in their ability to control blackgrass.

"Of all the pre-emergence herbicides tested in comparative container studies, flufenacet gave the greatest level of control across all populations of blackgrass; giving 99% control of the highly susceptible standard population, 96% control of the partially resistant population and 88% control in the highly resistant Peldon population," explains Dr. Moss.

"It's important to stress the importance of using pre-emergence herbicides, such as Sunfire and System 50, to help compensate for the declining control of post-emergence herbicides due to resistance," he believes, especially as 97% control needs to be achieved to stop blackgrass populations from increasing.

The key point to come out of research is that, of all the active ingredients tested, flufenacet is less affected by resistance. On a practical level this means there is a much smaller drop in the year on year efficacy of flufenacet (< 0.8% per year) and less likelihood of selecting for resistance, in spite of the fact flufenacet is being used widely already.

"The reason for this is that flufenacet tends to be used alongside other herbicides and those other herbicides are not acting in exactly the same way as flufenacet is. So, by using a range of different modes of action, you can actually slow up the development of resistance," explains Dr. Moss.

"The emphasis now must be on a more rational use of pre-em herbicides in combination with non-chemical methods to control blackgrass," he says. "Flufenacet, the active ingredient in Sunfire and System 50, should be seen as an essential component of any pre-em programme aimed at controlling resistant blackgrass."

Inez concludes that, Certis will be supporting a number of tank mixing options for Sunfire and System 50, which can be applied to winter wheat and winter barley crops, up to GS23 or before December 31st in the year of planting.

Notes to Editors:

Sunfire and System 50 supported tank mixes on the label are Hurricane® (diflufenican) and Toppel® (cypermethrin).

Sunfire and System 50 will be available on-farm autumn 2015 through a network of distributors. For further information relating to the product and its distribution, please contact Inez Cornell, Certis arable product manager.

Hurricane is a registered trademark of Adama Agricultural Solutions UK Ltd
Toppel 100 is a registered trademark of UPL