Registration of ‘Rulon’, a six-row, spring feed barley

In Utah, spring feed barley (Hordeum vulgare L.) is commonly used in rotation with hay to supply the state's animal products industry. The objective of this research was to develop a spring feed barley cultivar with improved agronomic performance and adaptation to Utah's growing conditions. ‘Rulon’ (Reg. No. CV-382, PI 705157, PVP no. 202400311) is a six-row, spring feed barley cultivar developed and evaluated as UTSB10905-72 and released in 2023 by the Utah Agricultural Experiment Station (UAES). Rulon was derived from the cross UTSB2120-36/‘Goldeneye’. Goldeneye is a six-row spring feed barley cultivar released by UAES in 2005. UTSB2120-36 was an F₄-derived experimental line from the cross ‘Century’/‘IdaGold II’. Rulon was selected through a modified bulk breeding scheme from the F₂ to the F₄ generations. Derived from the F₄ generation, Rulon was tested in replicated yield trials in Logan, UT, from 2013 to 2020, the University of Idaho (UI) Extension Variety Trials in 2016 and 2017, and the Western Regional Spring Barley Nursery from 2016 to 2018. Rulon yielded an average of 5987 kg ha⁻¹ in Logan, outperforming all check varieties, and showed similar days to heading compared to Goldeneye. In the UI Extension Variety Trials, Rulon showed higher kernel plumpness (95%) compared to the check varieties (76–88%). In the Western Regional Spring Barley Nurseries, Rulon ranked among the top five yielding entries in 15 out of 25 site-years. Rulon was released on the basis of its high grain yield, excellent kernel plumpness, and high test weight.