Laser weeding

Technical articles - Conserwa

Weed management Weeding robot

Laser weeding uses a powerful light beam to burn and kill weeds. The energy emitted by the laser is actually absorbed by the plant, causing a rapid increase in the internal temperature of the weed, then the plant proteins are denatured, the plant cell membrane is destroyed, and the plant tissues dehydrate. In conclusion, the weed loses its physiological functions which allows its elimination.

This method is very effective when the weed is young (from the cotyledon stage to “two leaves”) because the plant has fewer underground reserves to regrow after the burning of its aerial part. To optimize the absorption of energy by the plant molecules, mainly water and chlorophyll, the choice of wavelength is crucial.

How laser weeding works

Laser weeding relies on three phases:

• perception which consists of collecting images and monitoring the robot's position in real time (using USB and binocular cameras)
• decision, a process of analyzing and identifying the collected information (weeds, spatial organization of plots, etc.) thanks to a deep learning algorithm (YOLO, Faster R-CNN, CNN…)
• execution, the final phase allowing to control the laser emission so that it is precise and effective.

Types of laser

Laser type	CO2 Laser	Blue Laser	NIR/fiber Laser
Wavelength	10,600 nm	450 nm	2000 nm
Advantages	Very powerful Effective on all types of plants	Very precise Small machine Targeted area Less expensive	Heats the plant quickly
Limitations	Large Expensive High consumption	Less powerful Slower	Rarer Expensive
When to use?	Large crops Large or perennial weeds	Vegetables Crops in tight rows Young weeds	Specialized use Semi-industrial
Safety	Requires more protection (class 4, dangerous for eyes)	Less dangerous but glasses and precautions mandatory

Maintenance

Maintenance costs vary depending on the size of the machine, annual use, and model, however, maintenance always includes:

• cleaning optics (cameras, lenses)
• checking laser cooling
• software updates
• chassis and sensor maintenance

Purchase cost of machines

Laser weeding machines are currently very expensive:

• the price depends on size and configuration; large-scale machines can cost over one million euros
• machines are available for rent starting at €1000/ha for the most compact models

In the short term, herbicides are cheaper; however, in the long term, depending on annual use of laser weeding and considering its benefits, this method can become cost-effective.

Main agricultural laser weeding machines on the market

Model	Description and features	Laser technology / specificity	Speed	Images
LaserWeeder G2 (Carbon Robotics)	Tractor-mounted / semi-mounted system Submillimeter precision Several sizes available	Laser diode	0.61-1.21 ha/h
WeedBot Lumina	High-precision laser weeder for vegetables / dense crops Covers multiple rows Precision about 2mm	High-precision blue laser	Up to 600 m/h
Escarda Technologies	Towed machine with multiple lasers AI for recognition from 3mm	Lightweight and modular system

Advantages

• No soil disturbance.
• No environmental impact since the laser leaves only ashes behind.
• Reduces manual labor.
• Targeted.

Limitations

• High cost.
• Sometimes slow working speed.
• The machine consumes energy.
• Less effective on large weeds.
• Less effective on weeds with deep roots.

Regulation and safety

Laser machines are classified into 4 categories according to their hazard level. Laser weeding is generally done using high-performance class 4 machines; farmers must then be trained in laser safety and wear appropriate protective glasses.

Videos

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Sources

• Christian Andreasen, Najmeh Salehan and Eleni Vlassi. 2024. Laser weeding: opportunities and challenges for couch grass (Elymus repens (L) Gould) control. [04/02/2026]. https://www.nature.com/articles/s41598-024-61742-8
• Runze Jiag, Caixia Song, Chengming Wang and Tong Xu. 2025. Precision Weeding in Agriculture: A Comprehensive Review of Intelligent Laser Robots Leveraging Deep Learning Techniques. [04/02/2026]. https://www.mdpi.com/2077-0472/15/11/1213
• Robbie Lockie. 2024. Laser-weeding: a game-changing technology for sustainable farming. [04/02/2026]. https://www.foodfacts.org/articles/laser-weeding-game-changing-technology-sustainable-farming
• La France Agricole. 2022. New technology: A 3-point mounted laser weeding system at Carbon Robotics. [04/02/2026]. https://www.lafranceagricole.fr/actualites-machinisme/article/750687/un-systeme-de-desherbage-laser-3-points-porte-chez-carbon-robotics