Registration of ‘Top Shelf’ barley: The first glycosidic nitrile-null, winter malting cultivar to be released in North America

Abstract

‘Top Shelf’ (Reg. no. CV-380, PI 704478), experimental designation DH162310, is a two-row winter barley (Hordeum vulgare L.) released by Oregon Agricultural Experiment Station in 2023. It is a malting cultivar that is known to be a non-producer of glycosidic nitrile (GN0). GN0 is the precursor to a regulated compound (ethyl carbamate) in distilled spirits and thus, the GN0 trait is becoming a requisite for malting cultivars geared toward distilling. While GN0 spring cultivars have been available for over 20 years, Top Shelf is the first winter GN0 cultivar to be released in North America, and only the second globally. In addition to its GN0 status it exceeds contemporary agronomic and malt quality expectations. Over 5 years of field trials in Oregon it performed equal to or better than the check entries. It shows high yields, plump grains, and test weights. It also has good resistance to scald (caused by Rhynchosporium commune) and preliminary data suggest resistance to barley stripe rust (Puccinia striiformis f. sp. hordei). Results were confirmed in field trials in southern Idaho, a major malting barley production region, and a target environment for this cultivar. Under standard malting protocols Top Shelf meets the guidelines for malt and all-malt and/or grain distilling, and has high extract, enzymatic activity, and free amino nitrogen. When malted under optimized conditions, mimicking commercial distilling malt production, it produced even better results. As one of only a handful of GN0 cultivars available in the United States with potential for mainstream production, Top Shelf provides an important option for the distilling supply chain.