Time-series multispectral UAV imaging reveals dynamic N-responses and breeding gains for N-uptake and protein yield in Norwegian spring barley
Authors
Stefano Zanotto [1]
Constantin Jansen [2]
Morten Lillemo (presenting author) [1]
Affiliations
- Norwegian University of Life Sciences, Department of Plant Sciences, Ås, Norway
Email (presenting author): morten.lillemo@nmbu.no - Graminor AS, Ridabu, Norway
Keywords
plant phenotyping; plant breeding; trait improvement; protein content; nitrogen uptake; grain yield
Abstract
ProteinBar is a collaborative project along the grain value chain in Norway to ensure a better utilization of domestically produced barley for animal feed. Advanced sensor technologies are being used to gain a better understanding of the nitrogen (N) uptake and remobilization in the barley plants and build-up of grain yield and grain protein content. Field trials were carried out over three years with a set of 20 historical barley varieties grown at two different N fertilization levels, 90 kg N/ha and 140 kg N/ha, representing approximately 40 years of barley breeding. The trial was phenotyped weekly with multispectral UAV imaging, and in addition, Yara N sensor measurements from the tillering stage to anthesis. Flag leaf samples were collected at anthesis and analysed for N content. The normalized difference vegetation index (NDVI) was derived from the time-series multispectral data and dynamic phenotypes were calculated as genotype means through Gaussian approximation for each of the two N fertilization treatments. The results revealed a consistent trend with increased N uptake and grain yield in the modern versus older varieties. This trend was apparent for both 2-row and 6-row barley. Conversely, there was a negative trend for protein content, likely due to a dilution effect from the higher yield levels of the modern varieties. Parameters derived from fitted Gaussian curves of the NDVI time-series data could distinguish high-protein content genotypes with a more efficient N-translocation from the canopy to the grains from the high-yielding ones with prolonged grain filling to maximize grain yield at the expense of lower grain protein content. Results from testing this approach in genome-wide association studies to identify genetic loci underlying these different N mobilization strategies in a panel of 250 barley genotypes tested in field trials over two years (2024 and 2025) and two locations (Ås and Bjørke) will be presented at the conference.
Funding
The Research Council of Norway, NFR 336315. Project coordinator: Morten Lillemo