This 3D-Printed "Reference Sugar Beet" Could Transform Crop Phenotyping — And You Can Print Your Own

Researchers from the Institute of Sugar Beet Research and the University of Bonn have come up with a novel way to develop better crops: by laser-scanning a field and 3D printing models of the result — and you can even print a "reference" sugar beet of your very own.

"In the field of three-dimensional plant phenotyping, the referencing of utilized sensor systems, computer algorithms and captured morphological parameters represents a challenging yet fundamentally important task," explains first and corresponding author Jonas Bömer. "The application of additive manufacturing technologies for the generation of reproducible reference models presents a novel opportunity to develop standardized methodologies for objective and precise referencing, thereby benefiting both scientific research and practical plant breeding."

The team's work is split into two parts. The first is data-gathering: a real-world sugar beet plant, grown under greenhouse conditions, is selected as a reference — then scanned using a Far Focus S70 LIDAR scanner, creating a point cloud of the plant's above-ground portion. This is then lightly edited — increasing the thickness of the leaf blades and stems beyond the real-world model — in order to make a more robust model suitable for 3D printing.

That forms the second part of the work: using an off-the-shelf Prusa i3 MK3S+ 3D printer to create a physical "reference sugar beet" — which was then scanned again, using a Perceptron ScanWorks V5 line laser scanner mounted on a Hexagon Romer Infinite 2.0 measuring arm, to create a high-accuracy digital model of the finished physical print that could be used to see how the model fared under real-world usage.

That usage: phenotyping, the process by which plants are analyzed and compared to a reference ideal in order to inform breeding and detect growth issues. The 3D-printed "reference beet" can act as a control, the researchers explain, for automated data-gathering systems — including, in one experiment, a robot fitted with 20 digital SLR cameras and two line scanning lasers, capable of creating a point-cloud of an entire field of beets far quicker than a human could take measurements of each plant.

"The value in a printable 3D model is that you can print multiple copies, one per field of crops," Chris Armit, data scientist for the journal GigaScience, explains. "As a low-cost phenotyping strategy, where the major cost is the LIDAR scanner, it would be fantastic to see this approach tested on other crops such as rice or African orphan crops, where there is a need for low-cost phenotyping solutions."

The team's work has been published in GigaScience under open-access terms; the 3D model has also been uploaded to Thingiverse, under a public domain license, allowing anyone with access to a 3D printer to have their very own "reference sugar beet."