Test | Precision sprayer with potential from Rumex
This year, the German manufacturer Rumex introduced a 9-metre spot sprayer to the market. The machine is primarily intended for use in arable farming. Future Farming visited a grower in the Dutch province of Friesland for a first impression. The machine performs well, but the algorithm still has room for further development.
As the Rumex spot sprayer moves across the field, we occasionally hear (and see) one of the spray nozzles activate. The RXF 900, with a working width of 9 metres and a nozzle spacing of 4 cm, applies herbicide in a site-specific manner based on camera images. Using the algorithm (the software that rapidly analyses the camera feed), the machine can detect volunteer potatoes, sugar beet, monocot and dicot weeds, and dock in grassland. While driving, the camera identifies the selected weeds or crop, and sprays a weed when the boom passes over the plant.
Thanks to this site-specific spraying, a grower can save between 80 and 90% of the crop protection product. Moreover, the onions and beets in the field experience less growth stress, as most of the crop does not come into direct contact with chemicals. Due to the lights mounted next to the cameras, the machine can also operate in the dark.
Scroll down for the final verdict
Control via tablet
The operator can use a tablet to select which plants should be sprayed. Selecting the crop and treatment type, and setting threshold values is quick and intuitive within the app. The tablet is also used to adjust all other machine settings, such as defining a safety zone (spray-free margin) around the beet plants or the spray timing.
The setting most commonly used by growers is the threshold value. This indicates how certain the machine must be of a weed’s identification before activating the spray nozzle. If the threshold is set to 0, the plant will only be sprayed if the machine is 100% certain it is a weed. With the threshold at 100, the sprayer activates if it is ‘possibly’ a weed. In practice, the threshold is set between 25 and 90. Our host in Friesland had it set to 75, to ensure that all volunteer potatoes would be sprayed.
The Rumex has a 200-litre tank for the spray mixture, with an additional 40-litre clean water tank for flushing the system after use. Optionally, Rumex offers a larger clean water tank for €7,500, which can be mounted on the rear linkage. This tank can carry extra water, which the importer Landkracht recommends, so that the operator does not need to return to the yard to refill the sprayer.
95% drift reduction
Spot sprayers do not currently have a specific legal classification within spraying legislation. At the importer’s request, Rumex supplies the spot sprayers in the Netherlands with a specially developed hood around the machine. As a result, the machine is registered as a hood sprayer, qualifying it for a 95% drift reduction rating.
Further development
Joost ter Horst, owner of Landkracht, states that the machine is still under development and that the algorithms for arable crops are still being optimised. According to him, the RXF 900 has already demonstrated significant capabilities. However, he acknowledges there is still room for improvement. The end users share this sentiment, indicating that while the machine works, the algorithm could be improved further.
Landkracht maintains close contact with the German company Rumex regarding machine development. Features such as an adjustable spray surface (depending on the product used) and a configurable safety zone around the crop are being developed based on the information gathered by Landkracht. Since the start of this season, the RXF 900 has received eleven software updates to improve plant recognition and add new software features.
In addition to new functionalities and improved algorithms, consideration is also being given to adding new crop types. Currently, the manufacturer and importer are working on including chicory and broccoli as recognisable crops. However, Ter Horst does not wish to comment on how advanced this process is.
Licence fees
The Rumex RXF 900 is priced at €119,500 ($135,615) this year. That is the net price. Additionally, Landkracht has arranged that end users do not need to pay licence fees as long as they share all machine data to help improve the algorithm. Ter Horst also mentions that the company has not yet decided what will happen with licence fees for arable crops in the future. This depends entirely on how far the algorithm has been developed and what the market can bear. He says that customers will only be charged licence fees if the algorithm functions flawlessly. The purchase price of the 2026 model is still unknown.
This is the first year that Rumex spot sprayers are being used in arable crops. Thirteen machines have been sold in the Netherlands — all of which were offered to Landkracht and are now collecting data to improve the machine.
