Robotics in Sugar Beet Cultivation – Field Robots for Sustainable Weed Control
Introduction
Sugar beet cultivation is currently facing major challenges. In addition to economic viability, diseases and pests such as the SBR/Stolbur complex and cercospora, as well as weed control, are of critical importance to growers. The number of approved crop protection products is declining, while rising labour costs and the availability of manual workers pose significant challenges, particularly in organic farming. Hoeing robots are regarded as one of the most promising innovations. They are increasingly being used in organic systems to replace labour‑intensive manual weeding with intelligent mechanical hoeing technologies.
The Kirschgartshausen research farm, operated by Südzucker Landwirtschaft, has in recent years focused on testing alternative weed‑control methods. These range from tractor‑mounted in‑row hoeing systems (Garford, Steketee), to conventional mechanical hoeing combined with band spraying, through to innovative approaches such as spot spraying (ecorobotix) or electrical weed control (Zasso). Of particular interest are the autonomous systems from Farmdroid (Denmark), Farming Revolution (Germany) and Naïo Technologies (France). The aim is to test these new approaches side by side in the field—both in combination and by comparison—in order to generate practical experience and trial results for farm application.
Comparison of Field Robotics Systems
In recent years, two autonomous systems have been tested intensively at the research farm. Manufacturers have further developed the machines year after year. While Farmdroid FD20 is a specialised system for sowing and hoeing sugar beet based on GPS technology, the farming GT offered by farming revolution uses camera systems to distinguish weeds from crop plants. It operates using artificial intelligence (AI) and can be deployed in more than 100 different crops. This allows sowing to be carried out independently of the robot using conventional farm equipment.
In contrast, Farmdroid must carry out the sowing operation itself in order to place the seeds with high precision. The advantage of both systems lies in their ability to hoe within the row, very close to the crop plant, without causing damage. A new development is the combination of precise hoeing robots with targeted application technology. In addition to crop protection products, liquid nutrients can also be applied. Compared with broadcast applications, input volumes can be reduced by more than 90 percent.
Practical Weed Control Trials
New technologies require new experimental designs. Conventional small‑plot trials involving three or six rows over a length of six metres are not suitable for realistically testing hoeing robots that can be up to three metres long. For this reason, a much larger field design was developed in Kirschgartshausen, with plots measuring 50 metres in length and 12 rows in width, arranged in a fully randomised block design with four replications.
Within each 270 m² plot, assessment windows were established in the centre of the plots. In addition to weed infestation, crop density was recorded after each treatment. Comparison with untreated control plots allowed both weed‑control efficacy and potential crop damage to be documented.
Südzucker Landwirtschaft has had access to results from alternative weed‑control trials using field robots since 2020. The results from the past three trial years, presented in bar charts, are comparable and meaningful due to the continued development of the systems. The blue bars show weed assessments for the farming GT, the green bars represent mean values from plots treated with Farmdroid, and the grey bars show the untreated controls.
Across all three years—with very different weed pressure levels—the hoeing robots achieved a significant reduction in weeds. Control efficacy ranged between 90 percent and nearly 98 percent. In two of the three trial years, the autonomous systems achieved results comparable to three standard post‑emergence herbicide applications. Under very high weed pressure, as in 2025, the robots were unable to fully clear the plots of all weeds.
When considering crop losses, the hoeing robots also performed well. They operated significantly more gently than conventional mechanical cultivation using hoes and harrows, which caused significant damage to sugar beet plants. Results for Farmdroid showed that crop losses did not differ significantly from the untreated control in any of the three years. The camera‑based farming GT performed similarly, although under high weed pressure in 2025 it caused higher losses. A crop density of over 90,000 plants per hectare, as achieved with farming GT, is not expected to negatively affect yield. The advantage of the farming GT’s slightly more aggressive hoeing tools lies in its ability to control larger weeds.
Recommendations for Practical Application
The trials demonstrated that, over three years with very different weed infestations, both hoeing robots achieved a significant reduction in weeds. With control efficacy exceeding 90 percent and low crop losses, a substantial reduction in manual hoeing hours can be achieved in organic farming.
Despite the very positive trial results, the use of autonomous hoeing systems in practice is often limited and must be carefully considered on a farm‑specific basis. Operating performance is restricted by working width and speed. The systems perform best on large, level fields with minimal turning requirements. Operation on side slopes, stony fields or mulched surfaces is not recommended.
Alternative weed‑control strategies continue to evolve in practical farming. Some conventional farms are already gaining experience with combining the new technology with spot spraying. At present, despite high savings potential in crop protection inputs, this approach is not yet economically viable.
However, technologies are advancing rapidly, increasing operational reliability. Additional systems such as Ara by ecorobotix, or the integration of weed control with conventional sprayers via band spraying or spot spraying, are under development. These may become part of innovative future solutions for sugar beet cultivation—along with technologies such as drone‑based weed mapping, followed by targeted control using on‑farm sprayers.