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Integrated Management of Herbicide Resistance - LK0965

Failure to combat herbicide resistance poses a major threat to the sustainability of current cropping practices. Resistance can result in increased use of herbicides, limits cropping and herbicide choices and may encourage inversion tillage rather than minimum tillage practices that have environmental benefits such as a reduced risk of soil erosion, lower energy requirements and diffuse pollution.
The CSL Pesticide Usage Survey of Arable Crops in Great Britain in 2002 (Garthwaite et al., 2003) showed that herbicides were the largest group of pesticides applied, accounting for 71% by weight of all pesticides used. In addition, grass weed control was shown to be critically dependant on only four herbicide types - almost 90% of all grass weed herbicides applied were ureas, dinitroanilines, ACCase or ALS inhibitors. The limited number of herbicide types currently available, the withdrawal of approved products or uses as a consequence of the EC Review of Pesticides (Smeets, 2003) and little prospect of any new modes of action in the near future, is of major concern in relation to sustainable resistance management.
As a result of recent research, there is now a good base of evidence on the risks of development of resistance to ACCase herbicides (‘fops’ and ‘dims’) in grass-weeds. The major risk is now associated with the potential increase of herbicide resistance to ALS herbicides (includes sulfonylureas) in grass weeds. This was also rated as the most important future herbicide-resistance issue a recent European survey (Moss, 2004).
A key element requiring investigation is the effect of weed population dynamics on herbicide risk mitigation strategies, such as the use of mixtures or sequences, the rotational use of different modes of action and cultural control measures. Industry, advisers and regulators need to know whether selection pressure lessons from ACCase herbicides can be applied to ALS herbicides in grass weed species (black-grass, Italian rye-grass and wild-oats). If this is possible, it will provide much better information on the resistance risk of both existing and new modes of action and the potential value of risk mitigation strategies.
Time-Scale and Cost
From: 2005

To: 2009

Cost: £483,385
Contractor / Funded Organisations
Bayer UK Ltd, BASF plc, Home Grown Cereals Authority, ADAS UK Ltd., Syngenta Crop Protection UK Ltd, Du Pont (UK) Ltd, Rothamsted Research (BBSRC), Dow Agrosciences Ltd
Agricultural Land              
Arable Farming              
Herbicide use              
LINK Programme              
Pest and Weed Control              
Plants and Animals              
Sustainable Farming and Food              
Weed Control