Lodging Tolerance of Winter Rye ( Secale cereale L.) in Genetic Resources Compared With Commercial Entries and Test of a Provocation Trial

ABSTRACT Winter rye is the tallest small‐grain cereal and consequently more prone to lodging. Plant growth regulators are routinely used in commercial production to reduce the risk of lodging. To select genotypes with better tolerance to stem lodging despite its incidental character, we tested the use of a provocation trial with higher nitrogen level, no/less plant growth regulators for 16 varieties and 22 experimental hybrids and compared the results with a standard yield trial in 2024. The provocation trial yielded higher lodging scores (score 5.1 vs. 3.8) with comparable heritabilites ( h 2 = 0.75 vs. 0.72, respectively). The correlation between both trials was r = 0.88 ( p < 0.001) for plant height and r = 0.57 ( p < 0.001) for stem lodging at harvest. To estimate genotypic variation among genetic resources (GR), 118 testcrosses of international origin were analysed in a provocation trial in 2025 and compared with a set of commercial entries. Each of these experiments was conducted across three to four locations. Across all experiments, lodging tolerance ranged from 1.1 to 8.3, spanning nearly the entire 1–9 range. Significant genotypic variance was found among the GR testcrosses and standard entries. The best testcrosses with GR exhibited a lodging tolerance similar to that of the best experimental hybrid (score 3.2 vs. 2.8). In conclusion, some entries that could be used to further breed for lodging tolerance were found among the landraces and old varieties. The provocation trial should be supplemented by a subsequent yield trial for the selected entries to account for standard agronomic conditions.