First year results of ground-breaking trials undertaken to test a landrace wheat believed to be resistant to slugs could have far-reaching implications for how new technologies are tested in the field. Tom Allen-Stevens rounds up the findings to date, highlights how to get involved and offers an insight on what’s yet to come.
Ten UK farmers have successfully delivered an on-farm trial to explore the properties of a wheat believed to be resistant to slugs. But record low slug populations last autumn have meant results from the scientific trial – the first of its type to be conducted by UK farmers – are inconclusive.
The trial is part of a study, co-ordinated by BOFIN (British On-Farm Innovation Network), to help farmers move away from a reliance on chemical control measures and the potential environmental impact of those chemicals.
The ten “Slug Sleuths” – farmer members of the network – were contracted to establish a trial plot of Watkins 788, a landrace wheat variety never grown before on commercial farms in the UK. This was compared with their farm standard wheat variety and the farmers monitored the plots closely for slug activity.
The Slug Sleuths gather to discuss results of the ground-breaking trial.
The farms involved are spread across England, from Cambridgeshire to Devon, Oxfordshire to North Yorkshire. The Sleuths followed a protocol developed by BOFIN with Keith Walters, Professor of invertebrate and pest management at Harper Adams University, who also analysed the results. “The farmers did a first-rate job,” he comments.
“The detail of the trial requirements was delivered almost flawlessly. This gave us an excellent set of data up to the publishable standard you’d expect from professional trials technicians.”
Field trials are an essential element when testing new techniques and technologies, he points out, so the fact that farmers can set up and deliver valid results is significant.
“The implications are huge – If we can get scientifically sound results from a range of sites without sending research assistants all over the UK, that offers significant savings for field research.”
Keith Walters
However, the hot summer and dry autumn conditions confounded conclusions that could be drawn. Very few slugs appeared at establishment or soon after, when crops are at their most vulnerable to damage, and none of the wheat across the plots suffered significant damage.
“I’ve never known a year like it – it was good news for farmers, but sadly we are no closer to knowing whether this wheat does have a slug-resistant trait,” he concludes.
Ecological improvement
The first year of the Slug-Resistant Wheat project, which started in April 2022 and is led by BOFIN, is supported through a contribution by the Environment Agency as part of its Environment Programme. This supports partner-led projects in a Catchment Based Approach to improve the chemical and ecological quality of waterbodies.
Each of the Slug Sleuths drilled the trial within a first wheat crop, following oilseed rape, in a part of a field they knew was problematic for slugs. Four 20x20m plots were established – two of Watkins 788 while the other two were the farm-standard wheat variety. Two slug refuge traps were placed in each plot and monitored by the farmers twice a week.
“Previous research has shown this to be the right size of plot and distribution of traps to adequately monitor slug feeding behaviour. Ideally we would have liked more replication at each site, but the intention of the trial was as much about whether farmer-led trials would yield appropriate data, as the impact of the wheat lines on slug damage,” notes Keith.
A previous field trial had shown a significant difference in slug damage to the Watkins 788, but the plot was too small, due to limited availability of seed. It’s still unknown whether the landrace variety truly resisted slugs, or whether they simply moved next door to a plot of more palatable wheat.
“This time the plots were the right size, and we had ten separate trials, rather than just the one, to put the wheat to the test. But there simply weren’t enough slugs at any of the sites,” he reports.
Four 20x20m plots were established – two of Watkins 788 while the other two were the farm-standard wheat variety.
“Years of studies with refuge traps have shown you need at least 1.2 slugs on average per trap to reach a valid conclusion about any difference between treatments. The most we had in this trial was 1.07/trap, the next highest was 0.46/trap, and one of the sleuths recorded no slugs at all in traps.”
Plenty of beetles were found in the plots, however, which has spurred the sleuths on to find out more about their value as slug predators and how to encourage them in the field. Valuable lessons were also learned about monitoring methodology.
“The sleuths were asked to photograph the wheat at each visit and also provide a crop condition score based on their own farming experience” explains Keith. “But this is a subjective measurement and scores differed between sites for what was essentially a crop of the same condition. The photos, however, built into a very valuable record of crop growth at emergence. The question now is whether these are best assessed by the human eye or by a computer algorithm to detect differences.”
The monitoring also showed Watkins 788 generally emerged later and slower than the farm-standard variety. The very latest observations from the plots this spring show that the landrace variety has caught up with its modern counterpart, and on some farms sped through to stem extension earlier.
“The influence of early crop growth on its ability to withstand damage is something we should look at in year two,” notes Keith. “We’re also keen to scale up at each site with more replication, and will work with the sleuths to ensure we keep the trial design easy enough to implement.”
Genetic technologies
It was how the Watkins line behaved in lab-based feeding trials that initially sparked interest in the genetics, explains Dr Simon Griffiths at John Innes Centre, who leads the BBSRC-funded Developing Sustainable Wheats (DSW) programme.
“The Watkins Collection comprises 827 landrace varieties brought together in the 1920s and ‘30s before systematic plant breeding began. We’ve used genetic and genomic technologies to reduce these down to 120 representing the genotypic diversity of the original collection.
Simon Griffiths
“This is a far greater pool of wheat genetics than is currently available in elite lines, offering breeders traits that simply don’t exist in modern wheats,” he says.
These 120 wheats were screened through feeding trials at the JIC Insectary in 2015, as part of the Defra-funded Wheat Genetic Improvement Network (WGIN). Slugs were given a choice and their behaviour studied. Watkins 788 was a line consistently spurned.
“We firstly need to confirm this finding and the results of the 2016 small-plot trial (below), which is the purpose of the current field trials,” explains Simon. “We also want to understand what genes are contributing to that resistance.”
One of the aims of the current field trials is to confirm the results of previous small-plot trials showing Watkins 788 was consistently spurned. Source: John Innes Centre, 2016. Small plot trial at Morley Farms, Wymondham, Norfolk.
The DSW team of wheat genetics specialists aim to home in on Quantitative Trait Loci (QTL) – chromosomal regions believed to be responsible for a trait. They’ve taken Watkins 788 and developed 77 recombinant inbred lines (RILs) by crossing it with Paragon, a relatively modern spring wheat used frequently in research.
“The whole genome of Watkins 788 has been broken up and spread out over these 77 lines, so we can study them in detail and hopefully identify the QTL. Then we can pass the genetic markers for slug resistance to breeders, along with germplasm they can incorporate into their lines,” he continues.
Further feeding trials
First the RILs have to be studied through the same feeding trials that identified the initial discovery, to find out which have taken on the phenotype. This is the expression of slug resistance that be characterised by molecular markers. Those trials have just got underway, as part of the farmer-led project, conducted by Dr Victor Soria-Carrasco and the Entomology and Insectary Platform team at John Innes Centre.
“The aim is to identify several resistant lines we can multiply up for further in-field trials conducted by farmers,” says Victor. “But we’re not just testing the RILs. The farmers and others involved in the project have requested we test other wheat varieties and specific properties.”
Around the core group of Slug Sleuths is the BOFIN Slug Circle – over 100 growers, scientists and others kept informed of project progress through webinars and updates. They help direct and shape the trial and have highlighted key priorities for Victor and the team to test in the lab. While the RILs will be multiplied up for future trials, the Slug Circle have prioritised for properties that will be tested in the field this autumn:
Victor Soria-Carrasco
Run the initial test again to establish with certainty that Watkins 788 is disliked by slugs.
Test seed versus young shoots to determine exactly what it is that slugs like to eat and what they dislike about the landrace line.
Test a KWS Santiago x Graham line bred by John Blackman that may have a similar property – four of the Slug Sleuths have tested the line in the field trials alongside the Watkins 788.
Test against popular and upcoming commercial lines the Sleuths will be growing this autumn – KWS Dawsum, KWS Extase, Gleam, Graham and RGT Grouse.
Assess the effect of seed dressings.
The trials will take place over the spring and early summer while slugs are active, but Victor highlights that a shortage of the slimy pests could again prove to be a problem. “We need well over 1000 slugs to run these trials, so we’re appealing to farmers and others interested in getting involved to send in slugs.”
BOFIN is calling for Slug Scouts, who will capture grey field slugs and send them in to the lab by post.
BOFIN is calling for Slug Scouts, who will capture grey field slugs and send them in to the lab by post. Those who volunteer are provided with a pack that includes containers and postage-paid envelopes, as well as instructions on how to set up an effective ‘Slimery’. “This is what you use to attract and trap your slug population that you can then harvest periodically – it’ll want to be in the most slug-infested spot of your farm,” explains Victor.
Funding has been secured for a second year of the ground-breaking trial series and BOFIN is encouraging farmers, scientists and others interested in slugs to join the Slug Circle. From this, farmers will get the opportunity to become Slug Sleuths and be paid to take part in on-farm trials. BOFIN is also leading a major public-funded slug-management project, getting underway later this year, that will bring cutting-edge new technologies into commercial use.
Discussion and resources around the project can be found at the Slug Resistant Wheat project, hosted on the Trinity Pioneers platform.
Farmers have successfully delivered an on-farm trial to explore the properties of a wheat believed to be resistant to slugs. The first trial of its type to be conducted by UK farmers, results will be revealed at a webinar on Thursday 16 March at 8:30am.
The trial is part of a study, co-ordinated by BOFIN (British On-Farm Innovation Network), to help farmers move away from a reliance on chemical control measures and the potential environmental impact of those chemicals.
Ten “Slug Sleuths” – farmer members of the network – were contracted to establish a trial plot of Watkins 788, a Landrace wheat variety never grown before on commercial farms in the UK.
The trial compared Watkins 788 (left) with the farm standard wheat.
This was compared with their farm standard wheat variety and the farmers monitored the plots closely for slug activity.
The ten farmers followed a protocol developed by BOFIN with Keith Walters, Professor of invertebrate and pest management at Harper Adams University.
“The way the trials were established and data captured was a huge success,” comments Keith, who also analysed the results.
“This shows that farmers can set up and deliver valid results of field trials from a scientific study. These on-farm trials are an essential element when testing new techniques and technologies.
Keith Walters
“The implications are huge – If we can get scientifically sound results from a range of sites without sending research assistants all over the UK, that offers significant savings for field research.”
Keith will deliver the first-year results of this ground-breaking trial at the webinar on Thursday 16 March.
Anyone can attend and join the Slug Circle, a group of farmers and scientists who are helping to shape how the project develops.
Simon Griffiths
Also presenting at the webinar will be Dr Simon Griffiths, Group Leader of Designing Future Wheats at the John Innes Centre, who will bring attendees up to date on the genetics of Watkins 788 and the quest for a slug-resistant trait.
He will also highlight lab-based feeding trials, currently underway to explore further this wheat’s fascinating properties, along with other wheats undergoing tests.
The Slug Sleuths will then come together to discuss the trial and its implications for improving crop returns and reducing reliance on chemical control.
Slug Sleuth Jamie Melrose inspects a trap.
Chaired by BOFIN Founder and Oxfordshire farmer Tom Allen-Stevens, webinar attendees will be invited in to give their views and ask questions directly to the panel.
“We started this quest for a slug-resistant trait over three years ago, and it would never have got underway had it not been for the enthusiasm of the farmers who got involved,” notes Tom.
“We’ve not only proven the case for farmer-led research and directed cutting-edge R&D towards a much-needed in-field use, we’ve shown farmers can do the fieldwork to prove the concept.
“It means farmers can play their rightful role in delivering the Fourth Agricultural Revolution and accelerate adoption of some of the jaw-dropping genetic innovations currently being developed in labs and glasshouses across the UK.
“It will also help Defra direct some of the £168M of funding recently announced to encourage the take up of new technologies and advance productivity for UK farmers.”
The first year of the Slug-Resistant Wheat project, which started in April 2022 and is led by BOFIN, is supported through a contribution by the Environment Agency as part of its Environment Programme.
This supports partner-led projects as part of a Catchment Based Approach to improve the chemical and ecological quality of waterbodies.
Anyone can join the project for free and get involved in the Slug Circle – a group of around 60 farmers and scientists who have come together to explore alternative forms of slug control and who have helped shape the project as it progresses.
Driven and steered by the farmers themselves, at the centre of the project are the 10 Slug Sleuths, who carry out the on-farm trials with genetics expertise provided by Simon, and seed multiplied up by JIC at its Dorothea de Winton Field Station, Norwich.
The feeding trials are the final, new element of the project and involve “Slug Scouts”, volunteers who are gathering slugs from the field and then sending them in for the lab-based feeding studies. These are conducted by Dr Victor Soria-Carrasco and the Entomology and Insectary Platform team at the John Innes Centre.
Become a Slug Scout! Click here for a FREE Slug Scout pack, and here to find out more
The BOFIN ‘Slug-Resistant’ Wheat project is seeking ‘Slug Scouts’ to trap and send in slugs for feeding studies.
Farmers across the UK are being encouraged to capture grey field slugs and send them in to John Innes Centre in Norwich for a ground-breaking scientific study taking place early this spring.
The scientists are hoping farmers will harvest around 1000 slugs from their fields. These will be used for feeding trials just getting underway at the John Innes Centre Insectary.
The project, led by the British On-Farm Innovation Network (BOFIN), aims to gauge how palatable a range of different wheats are to slugs, and help farmers move away from a reliance on chemical control measures and the potential environmental impact of those chemicals.
It follows initial studies that indicated one landrace wheat, known as Watkins 788, may be resistant to the slimy pests, that cost UK arable farmers £100M every year.
“Slugs are UK arable farming’s most damaging pest,” notes Oxfordshire farmer and BOFIN founder Tom Allen-Stevens, who co-ordinates farmer involvement in the project. “As they get active again this month, rather than let them graze on our crops, we’re keen for farmers to join our group of ‘Slug Scouts’, who will trap the pests and send them in for this important study.”
The Slug Scout volunteers will be provided with a pack, including containers and postage-paid envelopes, as well as instructions on how to set up an effective ‘Slimery’.
“This is what you use to attract and trap your slug population that you can then harvest periodically – it’ll want to be in the most slug-infested spot of your farm,” explains Tom.
The trials are part of a wider project that aims to explore the palatability of wheat and the grazing behaviour of slugs, with the aim of identifying a possible slug-resistant trait for the development of future varieties.
Over the last 2 years, we have been putting the Watkins 788 landrace variety to test through analysis by scientists at the John Innes Centre and Harper Adams University, through on-farm trials by our Slug Sleuths and from slugs sent in by our Slug Scouts. Watch this video to find out what the results were of this incredible project.
Although this project has now come to a close, we are underway with another slug-focused project; SLIMERS. Make sure to join the slug circle to keep receiving updates and join in our mission to tackle arable farmings biggest pest:
Watkins 788 is one of a collection of landrace wheats currently being screened for interesting traits by scientists working on the Defra-funded Wheat Genetic Improvement Network (WGIN) programme.
10 Slug Sleuths, BOFIN farmers conducted trials for this project by following an in-field trial protocol drawn up by slug behaviour expert Professor Keith Walters of Harper Adams University.
Results can be found in the video above or by clicking here.
BOFIN members are taking part in what’s believed to be the first ever field trial of wheat to see if it’s resistant to slugs. Those interested can now join the Slug Circle.
Researchers at John Innes Centre have identified the potential trait in one of a diverse collection of landrace wheats currently being screened for properties of interest.
Alongside this line, some of the growers taking part in the trial are also testing an elite wheat, bred by UK plant breeder John Blackman, that may have the same property.
“We decided to screen some of the Watkins material for slug resistance as this was identified as a priority,” says Dr Simon Griffiths of JIC who carried out the work as part of the Defra-funded Wheat Genetic Improvement Network (WGIN).
This lab-based research singled out Watkins 788 as a variety slugs consistently spurn. The aim of the trials is to determine if this is also the case in the field, where the wheat will be the only food source available.
Ten farmers from Devon to Yorkshire have been growing the wheat in 20x20m plots within fields known to have a problem with slugs.
A protocol for how the trial is managed has been drawn up with the help of research staff at JIC working with Professor Keith Walters of Harper Adams University. He’s led an AHDB-funded project into slug behaviour that concluded in 2021.
Meanwhile, wheats bred by independent UK plant breeder John Blackman suffered sorely from slugs last autumn. But curiously there was one line the slimy pests barely touched. The site at Great Abington, near Cambridge, on alluvial, heavy boulder clay, is where John multiplies up promising lines and selects those to go forward for National List trials.
“I had about 30 pre-NL1 multiplications, but many of these were on a part of the site that suffered heavy rainfall soon after drilling in early November,” he recalls. Slugs moved in and hollowed out much of the seed before it had even germinated. “We never expected the slugs, but they were worse than we’ve ever had them.
“The pellet application we applied was too little, too late. Of the 30 lines, only 10 can be salvaged.”
One of these, located right in the centre of the worst affected area, is a KWS Santiago/Graham cross that appears relatively unscathed, despite all of the other candidates in the surrounding plots being almost completely obliterated.
“Every plant you get from an F1 cross is different,” explains John. “This one appears to have something in its genetics the slugs don’t like.” John kindly offered all of the remaining wheat seed from this particular cross to be included within the BOFIN trial. “This level of losses in an NL1 prospect is a disaster. Let’s hope something positive comes of it,” he says.
Four of the ten BOFIN members have been growing John’s wheat alongside the Watkins. Overseen by the scientists involved, the trial protocol was finalised through consultation with the trial farmers and through discussion with members of the BOFIN Slug Circle wheat.
Farmers, scientists and anyone curious about slug-resistant wheat or slug behaviour are encouraged to join the Slug Circle to gain insight on the project, share experience and shape how it evolves.
If there is a trait that can be bred into modern wheats, farmers in the Seed Circle will be the first to try it. This may take many years, but the aim will be to work with scientists to gain an insight into slug behaviour in the field and co-design strategies that will combat the pest in conjunction with genetic resilience.
“Slug management usually focuses on control of the pest, mainly through applying pellets,” points out Keith. “There is so much we now understand about slug behaviour that we can develop with growers, bringing in aspects of crop palatability.”
The aim is to develop understanding of farming systems at the same time as developing the next generation of wheats, explains Simon. “This is a far more sustainable approach than traditional plant breeding where the two are developed in isolation. It’s made possible through the introduction of new plant-breeding techniques that considerably shorten the timespan it takes to bring a new trait to market,” he notes.
Wheat believed to be resistant to slugs will be one of the star attractions at the Breeders’ Day at the John Innes Centre on Tuesday 21 June 2022.
BOFIN members have been invited to attend the event and a select few will get the opportunity to put this wheat to the test in a ground-breaking trial this autumn.
The wheat is one the Watkins Collection of landrace wheats currently being screened for interesting traits by scientists working on the Defra-funded Wheat Genetic Improvement Network (WGIN) programme.
A set of choice chambers was used that allows slugs to choose at random varieties they would like to graze and those they prefer to avoid. Researchers found there was one wheat that stood out as consistently spurned – Watkins 788.
“We don’t know yet whether this wheat truly resists slugs or whether they’d still eat it in a field situation where there’s no other choice,” explains Prof Simon Griffiths of John Innes Centre who leads the research.
Could landrace wheat Watkins 788 be resistant to slugs?
The concept was put to BOFIN members in 2020 and considerable interest came back in conducting trials of 0.4ha plots of the wheat – the area required to provide the optimal foraging distance to study the slugs’ behaviour.
“On the strength of this initial interest, we’ve spent the last two years multiplying up enough seed, and we’re now ready to go,” say Simon. The trial will start this autumn, closely monitored by JIC entomologists.
Only BOFIN members will be able to take part in the trial. Fields with a history of slug activity are sought, preferably following a crop (such as oilseed rape) that will promote slug activity.
As a landrace variety, Watkins 788 will not be an easy wheat to grow – it will be prone to lodging, susceptible to disease, and will not yield well. But following the monitoring, it will be important to bring the crop to yield with viable, clean seed as very little of the line currently exists.
“If the wheat truly resists slugs this will be a very valuable trait to pinpoint and bring into UK breeding programmes,” says Simon.
“Long term funding from Defra and Biotechnology and Biological Sciences Research Council (BBSRC) have given us the tools we need to identify the genetic basis of valuable pest resistance such as this.”
There’s currently about 0.5ha of the ‘slug-resistant’ wheat growing at John Innes Centre and BOFIN members have been invited to the Breeders’ Day on Tuesday 21 June to view it.
The plan is to have a ‘huddle’ next to the plot with Simon and other members of the research team to get an insight into Watkins 788 and the work they’re doing.
Any BOFIN member interested in taking part in the trial should contact tom@bofin.org.uk. They are also strongly recommended to attend the Breeders Day. To register, click the button below:
