Precision spraying is gaining ground
The spot sprayer is a new technology that is rapidly making its way into the market. Currently, several suppliers each have their own approach to achieving what a spot sprayer is designed to do.
Camera-guided spot sprayers are quickly securing a place in the market, both in arable farming and livestock farming. The first, most well-known, and so far best-selling spot sprayer in arable farming is the Ara from Ecorobotix. Last year, there were already around a hundred in use in the Netherlands. Rumex and Rumbojet made their debut in the livestock sector last year, offering spot sprayers primarily aimed at weed control in grassland.
These machines target weeds such as dock, dandelion, and ragwort, which are relatively easy to recognise using camera technology. Thistles remain a challenge, according to Rumbojet importer Jos Dijk, but it is only a matter of time. An ISOBUS connection is now available for the Rumbojet and will also be retrofitted to existing machines, Dijk adds.
Selection based on leaf size
Spot sprayers operate based on image recognition, although the Rumbojet selects more on leaf size rather than shape. 3 components are essential: the right camera, sufficient computing power, and a well-developed algorithm. Cameras and fast computers are readily available; the primary development challenge lies in refining the algorithm that translates images into the identification of weeds and crops. The company that masters this process best is already a significant step ahead of the competition.
Further development
The goal of a spot sprayer is to individually target plants with a crop protection product. This can lead to significant savings in chemical usage compared to full-field spraying while also enabling the application of herbicides that should not come into contact with the crop. A prime example is the control of volunteer potatoes in sugar beets or onions—an application that began in the Netherlands several years ago with the Ara Spot Sprayer. In grassland, the technology was initially used to combat dock. The algorithm determines how effectively the spot sprayer can distinguish between weeds and crops. Over time, these algorithms improve, allowing for the identification of a broader range of weeds.
However, real-world conditions can be unpredictable. Depending on weather conditions and growth stages, weeds can appear differently to the camera. A particularly challenging case is fat hen (Chenopodium album), which can resemble a sugar beet depending on its growth stage, as perceived by the camera. While cameras can be trained to recognise such differences, this requires additional development. If the camera can also reliably distinguish the crop, then (as seen with the Ara from Ecorobotix), the machine can incorporate a safety margin to maintain a certain distance from the crop when applying aggressive herbicides.
Continuous development and manufacturer support
In short, continuous development and manufacturer support for users are crucial in the world of spot sprayers. This is why Ecorobotix offers the option of purchasing specialist support from Doorgrond for a fixed seasonal fee. For Rumex and Rumbojet, support is currently free. The application in grassland is relatively straightforward, but as usage expands, increased support will be necessary. Importers indicate that future support may come at a cost. This is most concrete for Rumex, which is introducing its first spot sprayer variant for weed control in sugar beets and onions this year. Support remains free for now, but future pricing is under consideration, says importer Landkracht Agri.
Cameras and nozzles
One key difference between machines is whether the cameras operate under a protective cover and how precise the nozzles can spray. The number of nozzles per meter of working width does not necessarily indicate the effective spray width per nozzle, as this also depends on spray height. In some machines, spray height is adjustable. The arable farming variant of Rumex has a cover above the spray nozzles and features two lamps per camera, extending operational hours in the morning and evening. Experience with nighttime use is still lacking. For the grassland variant, lamps are optional.
UK and US spot sprayers
In the UK, Techneat is launching the Weed Wizard this year, based on Tillet & Hague technology and currently focused on onions. Dutch company Nanne Kooiman, based in Andijk, plans to introduce the Weed Wizard to the Dutch market. In the UK, Garford offers the Robocrop spot sprayer, but according to importer Homburg, it is not yet sufficiently developed for the Dutch market. Like the Weed Wizard, it operates without a protective cover and is thus more comparable to the Rumex.
In the US, Verdant Robotics is active in California with the Sharpshooter, a system similar to the Ara from Ecorobotix. At the previous Agritechnica, Bayer showcased a prototype of the 6-meter-wide MagicSprayer, still in development but following a similar path to Ecorobotix.
The complexity of developing a high-tech spot sprayer that meets the highest standards becomes evident from Verdant Robotics’ financial reports. In 2022, the company secured €46.5 million for further development and planned another funding round. Previous media reports indicate that Ecorobotix has also received similar financing rounds in the past.
