An onion (Allium cepa) cultivar trial is conducted in the Columbia Basin of Washington every year. The trial helps onion growers, packers, processors, and seed companies compare cultivars and identify those most suited to their operations. This report evaluates 54 onion cultivars that were in the trials 2 years or more from 2012 to 2014. Marketable yields of cultivars averaged 764 to 1314 cwt/acre. ‘TTA-747’, ‘Scout’, ‘SV6672NW’, ‘Montero’, ‘XP07716000’, and ‘SV4058NV’ had the highest yields. All cultivars produced more jumbo-sized (3 to 4 inches) bulbs compared with any other size category, but those with the largest percentages of jumbo bulbs were Utrero, Gunnison, and Sedona. ‘Scorpion’, ‘Ruby Ring’, and ‘Purple Haze’ had the largest percentages of medium (2.25 to 3 inches) bulbs, and ‘Montero’ and ‘Ovation’ had the largest combined percentages of jumbo and colossal (>4 inches) bulbs. Cultivar differences were evident in the 2012 and 2014 trials when many of the onions flowered (bolted). Cultivars averaged 0.0 to 15.5 bolted onions per plot when 2012 and 2014 results were combined. ‘Trekker’, ‘Highlander’, ‘Trailblazer’, ‘Ruby Ring’, ‘NUN8003ON’, and ‘Milestone’ had the fewest bolted onions. Cultivar differences were also apparent when several aspects of bulb quality were evaluated after 4 months in storage. ‘Utrero’, ‘Trekker’, ‘NUN7202ON’, and ‘Tamara’ had the most uniformly shaped bulbs. Bulbs of ‘Crockett’, ‘Legend’, and ‘Utrero’ had the most complete skins. ‘Crockett’, ‘Talon’, ‘Utrero’, ‘Legend’, ‘Gunnison’, and ‘Tamara’ had the firmest bulbs. Only 14 of 54 cultivars averaged more than 74% functionally single-centered bulbs. ‘NUN7202ON’, ‘Arcero’, ‘Joaquin’, and ‘Utrero’ had the largest percentages of bulbs with single centers or small multiple centers. There were more rots caused by bacteria (Enterobacter sp.) in bulbs produced in the 2014 trial than in 2012 and 2013, probably due to a high incidence of internal dry scale in 2014. Incidence of bacterial rot in cultivars was not significantly different in 2014, but there were some cultivar differences in 2012 and 2013. Incidence of fungal neck rot (caused by Botrytis sp.) in these trials was low and there were no significant cultivar differences. The results of these trials demonstrate that many new and advanced experimental cultivars have attributes that could make them a good choice for onion growers in the Columbia Basin.
Yield, Quality, and Storage Characteristics of Onion Cultivars in the Columbia Basin of Washington in 2012–14
