Investigating the distribution and presence, and potential for herbicide resistance of UK brome species in arable farming
About this project
Lessons learned from black-grass herbicide resistance build up tell us that careful attention needs to be paid to other high risk grass weeds.
Bromes are highly competitive weeds with infestations of sterile brome (the most abundant UK brome species) at densities of 5 plants/m2 causing up to a 5% yield loss. Bromes are perceived to be a growing problem by growers and advisors. However, there is little data on the presence, spread, economic impact and potential resistance status of the five problematic brome species in UK cereals. Herbicide resistant populations have also been found in France and Germany. Herbicide options available to control bromes are limited, with bromes possibly being less susceptible to chemical control than other grass weeds, making any further erosion of herbicide options, through development of resistance, of particular concern.
This four-year research programme will provide information on the potential for herbicide resistance evolution in UK brome weeds and identify methods to help slow or prevent resistance evolution of these grasses in UK arable farming.
The experimental work will use a combination of field surveys and glasshouse and container-based methods to determine the key objectives. The initial stage of the project will focus on all five UK brome weed species but later experiments will focus on the two species identified as being most at risk of developing herbicide resistance – sterile and rye brome.
The experimental work will include a UK wide survey of farmers and agronomists to determine the extent of the five main brome species in the UK, identifying areas where these cause major weed problems and where infestations are spreading. Glasshouse experiments will determine the range in herbicide susceptibility in brome species and whether bromes are naturally more tolerant to key herbicides and, in conjunction with field surveys, if populations are responding to herbicide selection pressure and becoming less susceptible. Potentially resistant populations will be tested and selection experiments will investigate if these brome populations can be easily pushed towards resistance through poor practice in the use of herbicides, to identify herbicide modes of action most at risk of resistance evolution. The best herbicide application timing will be determined to identify strategies to help maintain and improve herbicide control while also minimising the risk of resistance evolution.
The project will be managed by ADAS with collaborative involvement from Rothamsted Research, BASF, Bayer, Dow AgroSciences, and Monsanto. All members of the consortium will be involved with knowledge transfer and, in partnership with the Weed Resistance Action Group (WRAG), consistent messages will be agreed and widely communicated, especially to agronomists and farmers.
Farmers, agronomists, distributors and manufacturers will all benefit from improved understanding of the most effective use of herbicides to control bromes and appropriate resistance management strategies.
The clear guidance on best practice produced by the project will be accompanied by the economic significance of various management options. This will help farmers to select appropriate management options to maintain yields and profitability through optimal, rather than increased, herbicide use.