DOI: 10.5281/zenodo.16420898
title: Winter wheat performance data for varieties grown under low input conditions in Switzerland over the period 1990-2023, together with trial site weather data and variety genetic marker data

description: The dataset contains yield and grain protein content data for varieties of winter wheat (Triticum aestivum L.) grown at different locations in Switzerland in the period 1990-2023. The dataset also includes weather data for the respective locations and years, and SNP (single nucleotide polymorphism) marker data for the respective varieties. The varieties and locations have been anonymized using a code. The dataset has been used to develop yield and protein content prediction models which are published in (doi to be added upon publication). 

The grain yield and protein content data were collected in the frame of official Swiss winter wheat variety trials that test the varieties for their value for cultivation and use (VCU). The dataset published here is for low input conditions, whereas other conditions such as high input and organic are not included. The multi-environment trials were conducted by AGROSCOPE, the Swiss center of excellence for agricultural research, and took place across the Swiss wheat production zone (from Western to Eastern Switzerland, between 390 and 640 m.a.s.l.) (Herrera et al., 2020). A total of 16 variety trial locations are included in the dataset, with each location being present in 1-34 trial years. The dataset contains yield and protein content data for 98 winter wheat varieties, which are of both Swiss and foreign origin. Each variety was grown in 1-22 years at 8-16 locations. 

Reference

Herrera J.M., Levy Häner L., Mascher F., Hiltbrunner J., Fossati D., Brabant C., Charles R. & Pellet D., 2020. Lessons From 20 Years of Studies of Wheat Genotypes in Multiple Environments and Under Contrasting Production Systems. Frontiers in Plant Science, 10: 1745. doi.org/10.3389/fpls.2019.01745
description: Agronomic metadata  

Field trials were set up in a lattice design with three repetitions (plots) per variety. Sowing was done in October-November, depending on weather and field conditions, at a rate of 350-450 grains m-2. Plots measured 7.5 ± 0.9 m2 (1.5 m × 5 m) and were harvested per location using a combine harvester when the latest variety had a grain moisture content below 15% (in June-July). Grain yield (CO_321:0000013) was documented per variety and for each of three plots in dt ha-1 and at 15% moisture content. Grain protein content (CO_321:0000073, on a 0% moisture basis) was reported per variety and for a batch sample consisting of the harvest of three plots. No plant growth regulators or pesticides were applied, and herbicides only as needed. Fertilizer treatments consisted of 140 kg nitrogen ha-1, modified based on local practices and according to the “Principles of fertilization of agricultural crops in Switzerland” (Richner & Sinaj, 2017). Inorganic nitrogen fertilizer was split into two or three applications. Irrigation was used only in very exceptional drought conditions between flowering and harvest. Missing data are reported as “NA”.

 Weather data for the variety trial sites

Data on daily minimum, maximum and mean temperatures and total daily amount of precipitation were extracted for each location and year from the MeteoSwiss Spatial Climate Analysis products (1 km grid, Spatial Climate Analyses - MeteoSwiss). Daily solar radiation data were obtained for each location and year from the nearest automatic meteorological station (MeteoSwiss, Automatic measurement network - MeteoSwiss). Temperature and solar radiation variable data were averaged, and daily precipitation data were summed over six time periods corresponding to the winter wheat growing season in Switzerland: winter (October-February, sowing and vernalization), March (tillering), April (stem elongation), May (heading-flowering), June (flowering and seed filling) and July (harvest). The number of dry days per period and the mean precipitation on wet days (total daily precipitation > 1 mm) in each period were calculated. Missing data are reported as “NA”.

 Genetic marker data 

A total of 12106 SNP marker data for each of the 98 varieties is provided. The data have a SNP call frequency above 80%, a frequency of homozygous calls above 90%, and a sample call rate above 90%. The SNPs are encoded in the IUPAC notation (Cornish-Bowden, 1985) with ‘G’, ‘A’, ‘T’ and ‘C’ representing guanine, adenosine, thymine and cytosine bases, and ‘K’, ‘M’, ‘R’ and ‘Y’ representing combinations of these bases as specified in Cornish-Bowden (1985). Missing data are reported as “NA”.

 References

Cornish-Bowden A., 1985. Nomenclature for incompletely specified bases in nucleic acid sequences: recommendations 1984. Nucleic Acids Research, 13(9): 3021–3030. doi.org/10.1093/nar/13.9.3021

Richner W. & Sinaj S., 2017. Grundlagen für die Düngung landwirtschaftlicher Kulturen in der Schweiz (GRUD 2017). Agrarforschung Schweiz 8, Spezialpublikation, 276 S. https://www.agrarforschungschweiz.ch/2017/06/grundlagen-fuer-die-duengung-landwirtschaftlicher-kulturen-in-der-schweiz-grud-2017