In recent years, NIAB have been conducting research to help growers manage their oilseed rape crops in the presence of Cabbage Stem Flea Beetle (CSFB). We are all aware of the fact that in most of England, the area of this crop has been decimated and UK wide, we are now growing half the area we were before the removal of neonicotinoid seed treatments.
The autumn survey run by NIAB in recent years has shown the geographical spread of the problem with the map showing results from autumn 2019 with the red dots being crop failures and the yellow significant damage.
In light of widespread pyrethroid resistance, control of CSFB now relies primarily on a range of nonchemical control methods that either allow crops to avoid the pest or mitigate against its damage. However, more work is needed on a farm scale to identify how reliable these methods are, the situations in which they work best, and the benefits that can be gained by using multiple methods in concert.
We accept that what we have to do is learn to live without insecticides and manage our crops in ways that allow us to get at least a profitable yield in relation to the whole rotation but possibly less as a stand-alone cash crop. As a break crop, oilseed rape has performed greatly over the last few decades and our team feels that it still has a place in arable rotations. With this in mind, we now need to explore whether what we have learnt from small plot trial carries through into commercial crops. With that aim, csfbSMART has recently been launched. csfbSMART – ‘Sharing Management and Agronomy Research Tools’ – is a new industry-wide monitoring and trials programme set-up to test management methods for use against cabbage stem flea beetle on UK farms.
The programme connects two research projects investigating CSFB control. The first, ‘Reducing the impact of CSFB on OSR in the UK’ aims to improve understanding of the pest’s biology and investigate alternative management methods, led by ADAS and Harper Adams University and funded by AHDB and a consortium of industry organisations. The second, ‘CSFB: evaluating management of oilseed rape on-farm for maximum margins’, led by NIAB and Rothamsted is funded by Defra.
The coming together of these two projects along with the backing of the trade allows us at last to look at a range of management techniques that have developed lots of anecdotal information which pulled together over time will provide proper evidence. Growers and agronomists will be encouraged to sign up, but their level of involvement will be their choice, from providing cropping details to carrying out field scale trials. The team will provide advice as to what and how different management techniques can be carried out together with adult and larval monitoring techniques should growers wish to carry them out. Those carrying out field scale trials will be provided a point of contact who will stay in touch for the three-year duration of the project.
All of the team involved believe that csfbSMART is a unique, oneoff, opportunity, drawing together everybody’s knowledge and experience in a coordinated and sustained effort. We aim to support farmers, to monitor, assess and share information, building a national and seasonal picture of the pressures of CSFB larvae and adults within oilseed rape crops and the wider farming environment. One of the big issues in recent years has been crop establishment. Making use of available soil moisture has been key to getting the crop established. The project will give us the opportunity to collate information from a range of regions, soil types, drilling dates and varieties. We will be encouraging growers to assess and record the behaviour of their crops through emergence and into the autumn so that even where growers are not carrying out field trials, we still aim to collect information and in many cases, we will be able to add larval counts through the winter and into spring.
One comment we do hear is “I am trying this but have no idea if it is making any difference”. With the help of researchers and a coordinated approach, we aim to answer these questions and compare results with similar techniques in different regions.
We will also be looking to create clusters of growers with a dedicated contact to help share information and assist those who wish to explore new management techniques. Over the next few month, we will be rolling out information and kits to help with monitoring so that we can be ready to start in the summer. The project has had its first online meeting and we are excited that we have a range of growers looking to be involved.
We have a long list of questions including those below which with growers help and feedback, we aim to shed light on.
• Do organic amendments make a difference to larval numbers?
• Do WOSR volunteers left to grow close by make a difference? Can I manage volunteer OSR to increase effects?
• Does stubble height/management of the previous cereal make a difference?
• Should I establish WOSR with a companion crop? If so what?
• Shall I graze or mow my wellestablished crop to reduce larval numbers?
• How do I use trap cropping most effectively?
• Which variety is least palatable to CSFB?
• Which varieties recover best after CSFB grazing?
• Which varieties recover best from CSFB larval damage in the stem?
For several years, NIAB has been monitoring CSFB adults and we are looking to continue this whilst getting more growers involved so that they can begin to use better local knowledge to help them make their own decisions.
This will also include training and help with using the Syngenta water bath method for assessing larval numbers in the winter and spring. We will also be looking at novel techniques such as funnel trapping which has been tried on long term trial sites at Morley as another way of monitoring larval levels later in the year. The use of funnel traps (pictured below) within trials in 2018 and 2019 successfully captured falling larvae as they left the plants in the spring; on average 14 larvae per trap.
If scaled up this is approximately 5.5 million larvae leaving the OSR plants per hectare over the 24 day period, providing context to the scale of the issue growers are facing. This data also shows the potential of funnel traps as a low cost, relatively low input method of capturing larvae data in crops in order to be used for comparing methods of Integrated Pest Management in OSR. However, it is recommended they are used in combination with either one of or a combination of foliage and stem damage scores, yellow water traps and plant dissection so data from the novel method can be linked to pressures on crop and treatment effects.
We hope over time that this project will grow in size and that we can help growers to understand the best establishment and management techniques to help them manage their crops in the presence of this pest.