Blackgrass is one of the most economically damaging weeds in northern Europe and is exceptionally difficult for farmers to control.
In this short video, Dr Virginia Corless and Alice Hannam take you behind the scenes at our Yorkshire glasshouse research facility for a sneak peek at one of our most exciting novel mode of action discoveries yet: a new post-emergent herbicide targeting blackgrass in cereal crops.
With herbicide resistance a key threat to crop production across the world, we at Moa are working to develop herbicides with new modes of action that break this resistance. Worldwide, herbicide resistance has been reported in 273 different species, across 23 of the 26 known herbicidal modes of action [1].
To achieve our mission to break resistance we need to test our new herbicides on resistant weeds –Â and one of the worst species is right on our doorstep.
Blackgrass (Alopecurus myosuroides) is one of the toughest weeds in the UK and is resistant to multiple modes of action [1]. Annually, it causes £400million in lost profit to UK farmers [2] and can be so bad that in some cases farmers resort to crop destruction to prevent greater weed problems in following years [3].
Different blackgrass populations can have diverse levels of herbicide resistance to different herbicide modes of action, so it was important that our team collects samples from multiple populations. Resistance can be at the target site, where a mutation in the plant leads to the target protein no longer being sensitive to the herbicide, or non-target site, where in the case of blackgrass enhanced metabolism leads to the breakdown of a herbicide before it reaches its target.
Blackgrass seeds are ready to collect in early-mid July, so our team of Moa scientists including myself, Alice Hannam, Elisabeth Bowles, Tanya Mathie, Tom Clarke, Harry Wheelwright, Mark Bartlett, and Silvia Rubio-Diaz was standing by to make collections from farms in Oxfordshire, Wiltshire, Cambridgeshire, Lincolnshire, and Yorkshire.
The process starts with contacting local farmers to get permission to access their land and find the most infested fields – the more blackgrass there is, the more likely it is to be resistant. Fortunately (or unfortunately), most farmers are motivated and engaged in the fight against blackgrass and are happy to help. Some even come out to the field with us!
Blackgrass is easy to identify in the field, with the purple-green seed heads standing tall above cereal crops [4]. The seeds are ready to collect when around 25% of the seeds have naturally fallen off the seedhead and the remaining seeds come away easily. One blackgrass seed head can have as many as 100 seeds, and there can be as many as 500 seed heads per m2, meaning our team had no problems collecting large amounts of seed [5].
In July, we collected over 20 different populations of blackgrass but did not stop there, as blackgrass is not the only resistant weed in the UK. While out collecting we also took the opportunity to collect samples of Italian ryegrass (Lolium multiflorum), wild oats (Avena fatua), rye brome (Bromus secalinus), sterile brome (Bromus sterilis), great brome (Bromus diandrus), and groundsel (Senecio vulgaris).
The next steps involve cleaning the seeds to remove debris, breaking dormancy to ensure we get good germination, and testing our collections against a wide range of commercial herbicides to determine their resistance status.  The collections also help us refine our own novel herbicides to make sure they can control the toughest weeds that farmers face.
And of course, herbicide resistance is not just a UK problem, but a global one.  While it’s relatively straightforward for us to collect British weeds, it’s also critically important to understand how herbicidal resistance is increasing in other parts of the world, so we are engaging with international scientists to expand our collections and testing capabilities.
[1] International Herbicide-Resistant Weed Database
[2] The costs of human-induced evolution in an agricultural system
[3] Get timing right for blackgrass destruction
[4] Arable weeds: Basic black-grass biology
[5] Black-grass (Alopecurus myosuroides)
