The Challenge with Conventional Slug Control
Slug damage remains one of the most persistent challenges in UK arable farming. It affects establishment, reduces yield potential and adds cost at a time when margins are under pressure. Across the UK, slug damage is estimated to cost growers tens of millions of pounds annually, highlighting the scale of the issue. It also sits within growing pressure to reduce unnecessary chemical use and improve the environmental impact of crop protection.
Traditional control methods still rely heavily on blanket applications. While simple, this often leads to product being applied beyond the areas that actually need treatment, increasing both cost and overall chemical load.
This is the context behind SLIMERS (Strategies Leading to Improved Management and Enhanced Resilience against Slugs), a £2.6 million, farmer-led UK R&D programme funded through the Defra Farming Innovation Programme and delivered by Innovate UK. Running from 2023 to 2026, the project focuses on developing field-ready solutions that can be adopted at scale.
Within the project, Farmscan AG plays a central role in turning slug detection data into accurate and reliable in-field treatment. As part of SLIMERS, Farmscan AG is developing an autonomous spot-spraying system, designed to apply treatment only where slug pressure is identified. By connecting sensing, mapping and machine control, the system aims to improve the effectiveness of targeted application while reducing unnecessary product use and the environmental impact of existing broadcast methods.
A More Targeted Approach to Slug Management
SLIMERS combines real-time monitoring, predictive modelling and precision treatment systems to support targeted intervention.
Rather than applying product across entire fields, treatment is based on measured slug pressure. The project integrates AI-driven imaging, field-scale mapping and predictive modelling to build a clearer picture of slug activity across location and timing.
Being able to identify and locate slugs at such a high level of resolution enables the use of highly targeted application systems that can focus on high-risk areas. Farmscan AG is tasked with building and implementing the technology to ensure the data acquisition, and following slug management processes, provide highly accurate and consistent results in the field.
Farmscan AG’s Role: Delivering In-Field Execution
Farmscan AG is the automation partner within SLIMERS, responsible for converting sensing and decision-making into physical treatment.
This builds on previous projects such as Hands-Free Farm and Roto-Fence, where Farmscan AG utilised existing machinery, developing an autonomous retrofit kit for tractors and implements. These were demonstrated across a 42ha arable farm, and utilised on an autonomous fencing robot.
In SLIMERS, this capability is applied to an autonomous spot-spraying system. Farmscan AG focused on improving nozzle spacing, providing ISOBUS compatibility and utilising faster nozzle switching speeds. This would all be compatible with their existing autonomous system, providing a full solution for highly accurate in-field autonomous operation.
Connecting Detection, Decision and Action
The SLIMERS system links sensing and treatment into a single workflow.
Fotenix have built multispectral cameras and processing to detects individual slugs and generate application maps with accuracy down to 2 cm. These systems use advanced imaging and machine learning to deliver high-resolution field data.
These maps provide a slug pressure map that can then be precision sprayed to apply product only where required. Slugs are treated locally based on their exact locations, significantly reducing field coverage and the total amount of control product used. This integration ensures that detection data can be acted on immediately, bridging the gap between sensing and field application. Treatment is based on measured real-time slug pressure, reducing unnecessary application.
Precision That Improves Treatment Viability
Application accuracy directly influences which treatments are commercially viable.
Biological controls such as nematodes offer a more environmentally responsible alternative to traditional slug pellets, but their cost makes them impractical for broadcast application. Through targeting smaller high-risk patches, one of the benefits is drastically reduced usage of product, making alternative options such as nematodes, more economically viable.
Farmscan AG’s work focuses on achieving this level of accuracy, aiming to target 25x25cm patches with reduced nozzle spacing from conventional spraying. Sourcing faster switching nozzles allows smaller patches to be treated in extremely targeted, short bursts. These are essential for reliable performance, but is provided through utilising existing spray components, keeping the system viable for existing machinery and sprayers.
Built Around Existing Machinery and Integration
The system is designed to integrate with existing machinery.
ISOBUS compatibility allows connection with a wide range of tractors and sprayers, enabling use within established equipment platforms. The control systems were designed to be modular, fitting in with existing equipment as much as possible to provide an accessible platform.
Utilising existing GPS and spraying technology was a key part of making the technology cost effective and available across a broad range of systems. With the increase of ISOBUS platforms, providing this capability provides a clear pathway to integrate automation and spot-spraying into existing product lines.
Why Autonomy Matters in Slug Control
Slug activity is typically highest at night, when conditions are more favourable for treatment. This creates a challenge for manual operation, which can be difficult and labour-intensive.
Autonomous systems allow treatment to take place during these optimal windows. Machinery can operate overnight, targeting slugs when it is most beneficial, without requiring direct input and management from the user.
Field Application: What This Means for Farmers and OEMs
SLIMERS reflects a shift towards alternative methods of slug management, supported by more precise detection, application and machine control.
For growers, this creates a pathway to use treatment options that may otherwise be impractical at scale. By applying product only to identified areas of slug pressure, precision systems can reduce overall input use while making higher-cost alternatives, such as biological controls, more commercially viable.
For OEMs, the opportunity sits in modular integration. Rather than developing a standalone product, this type of technology can be added as a feature within existing machinery platforms. Farmscan AG supports this through scalable control systems, ISOBUS compatibility and integration expertise that allow automation and spot-spraying capability to be built into current equipment.
Bridging R&D and Real-World Outcomes
SLIMERS brings together research into slug behaviour with the development of more efficient treatment methods. By improving how slug activity is detected, mapped and understood, the project supports a more targeted approach to management, where treatment can be applied efficiently according to actual field pressure rather than through blanket application.
Farmscan AG delivers the control systems and automation required to support accurate, repeatable treatment under real farm conditions.
By bringing sensing, mapping and machine control together in a packaged end-to-end system, Farmscan AG helps each part of the workflow operate seamlessly. This reduces implementation risk and provides a clearer commercial pathway for growers and OEMs.
This integrated approach is central to bringing precision technologies into commercial use. Improved application accuracy reduces product use, lowers chemical load and moves slug control towards a prescriptive, as-needed methodology.
With the project extended through to August, the focus remains on refining and scaling these systems across commercial farming and OEM platforms.
Learn more about autonomous systems and how Farmscan AG is supporting field-ready precision agriculture solutions.