Autumn grass weed control

Grass weeds are one of the most challenging threats to UK arable crops – competing with the crops for resources and reducing yield. We’re here to help you tackle troublesome grass weeds such as black-grass and ryegrass head on.

High grass weed populations in many of this season’s crops will require a radical rethink for autumn strategies to get them back under control, including a combination of cultural controls and more robust herbicide programmes.

Cropping choice, variety choice, cultivation method, drilling date, seed rate, herbicides and application all have an important role to play. Stacking these building blocks of integrated weed management (IWM) is critical to achieving the 95%+ control required to prevent population increases. 

Take a look around and discover the latest tools, techniques, and insights for controlling grass weeds in your arable crops this autumn and beyond.

defy cube

Stacking herbicides maximises control and reduces the risk of resistance developing

defy cube

DEFY® is a core element of black-grass and ryegrass stacks. Always boosting levels of control.

defy cube

Application matters for effective control

Syngenta NIAB Black-grass and ryegrass trial Corringham

Syngenta and NIAB IWM trials

Syngenta has been collaborating with NIAB on trials to understand how UK farmers can best use tools such as hybrid barley and DEFY® in the autumn to manage black-grass and ryegrass.

In this latest video we explore and discuss a wide range of integrated control measures, and the benefits they individually and cumulatively contribute to grass weed control.

Thank you for watching and we hope that the insights and tips provided in this video help you to achieve improved grass weed control on your farm for a more productive harvest.

Weed seed dormancy challenges

Black-grass could prove more problematic this season, where a mix of both hot, dry and cool, wet conditions during the weeds’ flowering period could result in seed shed with highly variable dormancy.

That could see some germinate quickly, while others may take far longer to emerge.

Syngenta grass weed trials have shown that in a low dormancy year loading more active ingredients into a pre-emergence application and including robust rates of DEFY®, increased overall control by 22% over a standard pre-em strategy. In a high dormancy year, however, a shift to more of a sequence of autumn herbicides, incorporating DEFY® at peri or post-emergence, gave a 27% increase in control over the pre-em application alone.

What is seed dormancy?

There are several factors that influence when grass weed seeds germinate. One of them is dormancy. But what is it? And how does it impact farmers? Watch this video to find out.

Defy Product Information

Crop Protection
COMPOSITION: 800 gms/l prosulfocarb
PACK SIZE: 10 litres
CHEMICAL FAMILY: Thiocarbamate
FORMULATION: Emulsifiable concentrate (EC)

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