Robot combats powdery mildew in strawberries using UV-C treatment

22-12-2021 | Field robots | News

Thorvald is an autonomous robotic platform which currently focuses on reducing powdery mildew through UV-C treatment. According to manufacturer Saga Robotics Thorvald achieved complete control of the pathogen during this British growing season at both the farms it has operated on treating table top crops.

Thorvald has been on trial in the UK since 2019, but according to Saga Robotics 2021 has proven to be a watershed year with plant samples that have been examined having no traces of the fungal disease.

The robot delivered UV-C treatment to protect strawberry plants on approximately 10.6 hectares of land at Clock House Farm Ltd and 2 hectares at Hugh Lowe Farm Ltd, both in Kent, from March to October 2021.

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The size of the robot is adjusted to its surroundings. For instance, the version of the robot operating in strawberry table-top production in polytunnels has the shape of an arch to allow it to drive over the tables, fully submerging the plants with UV-C light. - Photo: Saga Robotics

No chemicals needed

During this period neither farm has needed to spray their strawberry plants with any kind of powdery-mildew-targeting chemical control agent.

Pål Johan, CEO, Saga Robotics, says, “Throughout the season, our robots have efficiently treated over 7,300 linear kilometres of strawberries with completely effective treatment, 100% robot service reliability and no failures. These results have only increased what was already strong interest in our service.”

How does ultra violet (UV) treatment of powdery mildew work and why is it so succesful? Read it here: Ultra violet lamp robots tackle grape powdery mildew

Scaling up capacity

The Thorvald UV-C treatment is commercially available. Saga Robotics says is scaling up capacity as fast as they can. “Currently we are not able to meet demand but would like interested growers to sign up for a waiting list so that we can plan the scaling in the best possible way,” states the company.

Robot as a service

Saga Robotics does not sell the robot, but the job it does. The company charges a fixed fee per Hectare (acre) which includes the operation of the robot. Hence the grower lets Saga Robotics know which plants to treat and Saga Robotics take care of it.

About Thorvald

The cost to the grower will depend on the size of their fields. Larger growers will need several robots to treat the entire production. – Photo: Saga Robotics

The approximately 200 kg robot is fully electric and can be charged on a regular power outlet. How long it can operate on one battery charge depends on the task. Saga Robotics plans the number of robots and the number of batteries needed for the job, so charging is not something the grower needs to worry about.
The robot navigates using advanced sensors for localization. This is used as input into the navigation software, which is developed in-house by the Saga Robotics team and allows the robot to follow the rows and drive between the rows and tunnels completely autonomously. The robot operates completely autonomously but is under remote surveillance by the Saga Robotics software team.
The size of the robot is adjusted to its surroundings. For instance, the version of the robot operating in strawberry table-top production in polytunnels has the shape of an arch to allow it to drive over the tables, fully submerging the plants with UV-C light. Its driving speed is adjusted to the job being done, which is usually below 5 km/h even though the robots can drive faster.