Rumex is a new ‘see and spray’ automated herbicide application system, developed by Lanark-based Taylor Technologies. Simon Henley finds out more about the company’s young founder and how the technology works.
A young man in Scotland is about to change the way we think about dealing with perennial and biennial weeds in grassland. The days of blanket spraying weeds in short-term, long-term, rotational or permanent grassland leys and pastures is increasingly becoming an unaccepted method of dealing with unwanted photosynthetic organisms, and it is the goal of one inspired entrepreneur from Lanark to change the way we deal with these weeds.
The careful management of weeds in farming has arguably never been more important. Chemical herbicides still play an important part in controlling weeds throughout the agricultural sector. Yet it is becoming increasingly vital to adapt the way we use these potentially harmful man-made elements, without harming the crop they are infesting or potentially doing damage to the surrounding environment.
Enter Colin Taylor. As a student studying his BSc in Agriculture at SAC in Edinburgh, Mr Taylor became fascinated with the subjects of agronomy and crop management. Having earned his degree, he went to work for Kettle Produce in Fife as a farm agronomist. Following his tenure working with the Kettle team, Mr Taylor stumbled upon an idea which has since become his life’s vocation.
“A neighbouring dairy farmer told me about a problem he had controlling docks in his grass fields,” says Mr Taylor. “His concern was that although he could kill the docks, the herbicide he was using was also stunting grass growth and killing the clover in the fields.
“With a large acreage of grass which was extensively affected by the docks, spot spraying using a nap sack was nigh-on an impossible task to utilise affectively. It was during our discussion when I realised there was technology already out there which could be adapted to potentially deal with this problem.
“It dawned on me, I could use existing technologies such as computer vision and artificial intelligence. These are systems already used for facial recognition and autonomous vehicle control and they could potentially be re-purposed to identify weeds.
“By combining this technology with an electronic control system on a crop sprayer, I realised I could develop a machine which could automatically spot-spray weeds, by only activating the sprayer nozzles over where the weeds are present.”
Having formulated an idea, Mr Taylor proceeded to build a prototype. Development on the system started in 2018 and became the focus of his Agricultural Technology MSc research project, while he attended the Royal Agricultural University in Cirencester.
The original prototype was built around a small frame, which was towed behind a compact tractor. With a camera mounted on the frame, the initial part of the development process was to gather thousands upon thousands of images of weeds, which were then uploaded and adapted to commercial computer vision software.
“The images of weeds are necessary for the computer to identify the plants of any size, shape or configuration,” says Mr Taylor. “With the help of a computer programmer, we have been able to write a software application which controls the system while it is working in the field.”
Mr Taylor has spent the past two-years developing a second prototype. Based on a second hand 12m Hardi linkage-mounted crop sprayer with a 600 litre tank, his work has involved perfecting the positioning of the cameras, the spray nozzles and electronic control systems, in addition to modifying and adapting the spray booms to enable continuous spot spray application at a commercially viable rate.
Spaced equally along the front of the boom 1.5m apart, the cameras are deliberately positioned ahead of the nozzles so they can identify the weeds. The 10 cameras on the 12m prototype require the boom height to be set at 1m from the ground.
The prototype features a three-section boom, with three spray nozzles per camera. The spot-spray nozzles, which are made by EvenSpray, are controlled individually by an electronically operated solenoid valve. Nozzles are mounted underneath the boom and deliberately angled to produce the most effective spray pattern, relative to the positioning of each camera.
As the tractor moves forward, the cameras continually produce a feed of images at 30 frames per second. From this data, the spray system computer identifies which plants are weeds and their exact GPS co-ordinates. This information is then saved, so the location of each weed plant is logged for future reference.
Having identified the position of the plants to be targeted, the computer activates the electronic valves on the nozzles nearest to the weeds. This can require a single action or simultaneous multiple actions, depending on the weed density. The electronic valves are opened for a pre-set time, based on the forward speed of the vehicle.
To overcome line pressure differentiations, as the nozzles continually open and close, Mr Taylor has modified the standard Hardi sprayer boom by adding individual recirculation systems to all three boom sections.
Variations in line pressure on each section are controlled by back pressure on a circulation manifold system, with excess liquid being returned to the tank. This has been done so the boom sections are always under pressure when the nozzles open, thus ensuring the correct spray pattern is continually executed.
“The herbicide used is mixed at the recommended dosage,” says Mr Taylor. “The volume of chemical (liquid) applied varies with the forward speed and the size of the weed being treated.
“Typically, an infestation of docks may cover up to 10 per cent of a particular field. By using this type of spot spraying technology, you are only using the amount of herbicide required to kill those weeds, or in other words 10 per cent of the spray which would normally be required to spray the entire field.
“We are currently still conducting field trials. It will take until the end of the year before we can fully evaluate the effectiveness of the system and its killing accuracy. However, from an operational perspective, to date we have estimated cost savings of 75 to 80 per cent and the interest we are getting from farmers all over the UK is extremely encouraging.
“At present this system is only for use with selective herbicides such as Doxstar (fluroxypyr/triclopyr). If you were to use a non-selective product like Glyphosate, the overspray from each nozzle, even though it is a tiny amount, would kill the grass surrounding the weeds.”
“Currently, the system has a recognition accuracy of 99.5 per cent for dock weeds indigenous to the UK. Another important factor is that docks are very similar to other grassland weeds. As a means of increasing the versatility of the system, we have been collecting data and conducting trials to control other broad leaved weeds, including biennials such as Ragwort and Scotch-Thistle.
“Other weeds such as Chickweed and Blackgrass are more difficult to identify for spot-spraying purposes, but the technology we are using has many other useful applications in the battle against weeds and disease, which we are also exploring.”
To date, Colin Taylor has orchestrated most of the development work on the Rumex project himself, in collaboration with computer programmers and software companies. By continually field-testing and developing the system, he believes there are many opportunities for vision-based automation technology within the agricultural industry.
“The potential of this type of technology for controlling pests and diseases is boundless,” says Mr Taylor. “We are on the journey to build a robust, reliable and effective system for automated weed control and I firmly believe systems like the Rumex automated herbicide application system will play an increasingly important role in the future of British agriculture.”