PUMA IV
On the right wavelength
Our patented KWS BEETROMETER® system determines the sugar content of a beet directly in the field. This innovative technology is also used in the new PUMA IV.
We started using the KWS BEETROMETER® directly in PUMA I in harvesting 15 years ago.
Determining the sugar in a sugarbeet might sound simple, but it’s actually quite a challenge. The traditional method, which we also use in our beet laboratory in Klein Wanzleben, involves shredding the beet using several saw blades and then mixing the resultant beet pulp. The sugar content and other quality parameters for this homogeneous pulp are then analyzed. It’s time-consuming, manual work – and all to be able to extract just 26 grams of pulp for analysis. Yet that work needs to be done quickly, because the unstable pulp oxidizes so rapidly that the sugar content in the sample changes after just a few minutes. A new method was therefore needed.
“We received our first request on the subject in 2003 from breeding,” recalls Elke Hilscher, Head of Chemical Analytics in Einbeck. “Back then, we were already determining the moisture content of grain corn directly on the combine harvester. So we thought: Why not adapt that for sugarbeet?”
It soon became clear that near-infrared spectroscopy (NIRS) would be the method of choice. In it, light in the near-infrared wavelength range is directed onto the sample and is absorbed differently by the molecules it contains, depending on the chemical structure. The non-absorbed parts of the light are reflected and can be recorded as a spectrum. The reflected light spectrum enables conclusions to be drawn about the constituents, such as sugar content, dry matter content or marc content.
However, due to its aqueous nature, a pulp sample cannot be analyzed optimally using NIRS, as the light is completely absorbed by the water. The question was therefore: How to produce a measurable sample?
“We get information in a very short time.”
Elke Hilscher
Rapid measurement
The solution is a flexible and modular system, the KWS BEETROMETER®. A conveyor belt transports the beets into a chopper, which shreds them. The chopped beets then pass under a pressure roller, creating a densely packed, homogeneous sample flow. It continues its way on a conveyor belt, where the NIRS measurement head swings over the sample at a distance of around 20 centimeters and records a spectrum every 30 milliseconds. More than 400 measurements on 40 kilograms of beet can be taken in just 20 seconds. “Unlike with the pulp sample, we now get the information from thousands of pieces of beet in a very short time,” explains Elke Hilscher, who helped develop the system. “The measurements are then averaged, and in that way we identify the entire heterogeneity of a beet.”
The sensor makes 400 high-precision measurements in just 20 seconds – and now also for other crops apart from sugarbeet.
Calibration of the NIRS sensor is at the heart of the system. “NIRS delivers information across the entire wavelength range. The information on sugar is contained everywhere, and now we have to filter what distinguishes these pieces of information from one another. Because they’re crucial to our measurements,” adds Elke Hilscher. Since we have been using the system for 15 years, we have many comparative values and can see which factors – such as temperature or soil properties – influence the spectra.
On board PUMA
What’s the biggest benefit of the KWS BEETROMETER®? It is flexible and is used directly in the field when the beets are harvested, which means the results are immediately available to our colleagues in breeding. It was first used in our PUMA (Plot Harvest Unit with Measurement Acquisition) in 2009. PUMA IV, the latest generation of harvester, will be used in fields starting in the fall of 2024. Construction work on it is still underway.
PUMA IV, which is still under construction, will also be equipped with the mobile analytics technology.
As a mobile sugarbeet analysis laboratory based on a self-propelled full-feeding sugarbeet harvester, the PUMA simultaneously harvests, processes and measures the quality traits of the sugarbeet. In this way, important data for breeding is obtained directly on KWS’ trial fields. The entire machine is linked to software that allows the operator to control each processing element. The KWS BEETROMETER® is installed directly in PUMA: A mobile NIRS sensor records the spectra of the sugarbeet samples, calculates the quality parameters and stores the data. Chemical Analytics in Einbeck ensures the reliability of the measurement results by regularly checking the data.
Our specially developed technology thus helps our breeders on the spot. Before NIRS technology was used, there were deviations of up to 1.5 percent in sugar content between candidate varieties in the field. Now promising candidates for lines and hybrids can be identified at an early stage, while the deviations have been reduced to 0.6 percent thanks to ideal breeding processes, which means high-precision measurement is a must. And the technology continues to grow, as we now use the innovative NIRS system not only for sugarbeet, but also for all other KWS crops.
More about the KWS BEETROMETER®
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