Prickly and promising


08 November 2023
Open day attendees get an insight into progress of project featuring two trap crops.

BUMPER crops of DeCyst™ Prickly and Broadleaf, two PCN trap crops, greeted those who attended a recent open day in Shropshire.

The open day event near Newport attracted potato growers, agronomists and stakeholders from across the supply chain, who were shown the latest progress made by the Innovate UK-funded project in their second year of on-farm trials. The trap crops were grown by host Neil Furniss and the team at Produce Solutions and have shown impressive project progress to date.

This year has seen particularly remarkable progress, thanks to promising findings regarding suitable pre- and post-emergence herbicides that can be used with trap crops to enhance their early competitive abilities, with the possibility of extended usage in the future pending extensions for use. 

Project Lead and Trials Manager at Produce Solutions, Dr Bill Watts, said: “Our project focusses on understanding the factors affecting trap cop success. Ensuring the DeCyst™ seed is shallow drilled into moist soil with some consolidation for seed-soil contact is critical to success. A follow-up residual herbicide such as aclonifen (Emerger®, Bayer) guarantees low weed competition until full groundcover (EAMU pending).” 

Part of the consortium, growers J. Bubb, J Foskett Farms and TC & N Taylor, have been focussing on optimising the best drilling practices to ensure the successful establishment of these challenging crops. Field scale trials have demonstrated that, despite being a small-sized seed, common combi-drills offer an excellent option for drilling the trap crop seed; possibly by raising moisture levels in the seedbed, thus encouraging germination. 

Another option is using precision vegetable drills where available, with Nick Taylor reporting favourable results with a precision-drilled seed mix of DeCyst™ Prickly & Broadleaf. As an organic grower, the lower level of soil disturbance with this technique also limits weed seed germination, keeping the crops clean. Alternatively, Shropshire-based grower John Bubb has seen promising results with interrow planting of DeCyst™ combined with clover and buckwheat in a standing crop of wheat, which flourished after combining, giving complete ground cover. 

Collectively, these efforts have accumulated compelling evidence on optimising the performance of trap crops and their integration into current farming systems. 

But getting the crop drilled is only half the challenge, next is ensuring good seed-soil contact owing to the smaller seed size and the drier conditions frequently experienced during the typical sowing window of May to June. Depending on the conditions, this might involve some consolidation to optimise germination and subsequent biomass growth.

Dr Ivan Grove of Curious Raven Ltd, who has been using UAVs to record biomass in the trials said: “Ground cover and crop volume has benefited little from using additional heavy flat rolls post sowing this year due to sufficient early rain after sowing.”
“However, using Cambridge rolls post sowing is always recommended to consolidate the seedbed for good soil to seed contact and reduce moisture loss.”

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Once establishment has been achieved and the weeds are under control, the goal is to maximise crop biomass to ensure high trap cropping potential. Additional management is needed to help reach the ideal target of >700 g/m2 or >7 t/ha for DeCyst™ prickly ensuring a high root density and sufficient exudate release to stimulate PCN hatch; work is ongoing to identify ideal biomass requirement for DeCyst™ Broadleaf and other species. 

Graham Tomalin of VCS Potatoes Ltd commented on the nutrition trials undertaken in the East of England this season. He said: “We’ve been looking at the canopy development across the three DeCyst™ species following applications of potash and phosphate at drilling, whilst also experimenting with the use of poly ammonium phosphate in comparison to standard granular Triple Super Phosphate (TSP). Although not yet complete, preliminary observations indicate that phosphate is important to maximise crop biomas.”

In parallel with the trial and current efforts to optimise the existing commercial products DeCyst™ Prickly and Broadleaf, the consortium has also been working on a new trap crop product known as DeCyst™ Podium (Solanum chenopodioides – tall nightshade). Researchers Dr Matthew Back and Dr Kasia Dybal have been delving into the efficacy of this new upcoming product, whilst the wider consortium has been exploring how best to grow in the field.

Dr Matthew Back, Reader in Nematology, and Dr Kasia Dybal, Researcher in Nematology, from Harper Adams University added: “To date we’ve examined PCN (Globodera pallida) multiplication within two glasshouse experiments when grown with and without the DeCyst™ Prickly, Broadlead, and Podium along with potato and fallow controls.

“So far, this has shown how higher biomass led to a greater reduction in PCN, with Broadleaf resulting in >75% reduction and 50% for Podium. We’re now moving on to see if this is also true for the other PCN species (G. rostochiensis).”

Those attending the open day shared their experiences with trap crops as well as thoughts on the project. For those who were new to trap crops, the event offered an introduction into the topic area and provided future ideas, highlighting the role of trap crops as part of an integrated pest management (IPM) approach to PCN, particularly when stacked with other tools such as rotations and conventional management practices.

Dr Alex McCormack, Innovation Sector Lead in Agronomy for project partner CHAP, said: “This is a great example of how public funding enables true cross sector collaboration and synergy by combining the skills, expertise and experiences of growers, agronomists, consultants and researchers to accelerate on-farm innovation.

“I’m eagerly looking forward to the next steps, where we will be working on creating a comprehensive grower agronomy guide and producing high-quality video materials to broadcast the message to growers and agronomists, so stay tuned and keep an eye out for upcoming developments!”

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