A market window for onion occurs when f.o.b. prices are above grower break-even price for a period of 4 to 6 weeks. Market windows were calculated to occur from late June to early August and from early October through December for northwest Texas onions. Five-year average prices ranged from $6.25 to $7.40 (1990–94), and a breakeven price of $5.38/50-lb sack was calculated from an analysis of total costs of production and marketing and historic yields. Ongoing research and grower demonstrations with advanced breeding lines, commercial cultivars, and selections from yellow, white, and red cultivars have defined certain cultivars that display superior attributes and mature within the market window. Superior cultivars adapted to the first market window include XPH-87N60, `Sunre 1445', `Sunre 1462', `Yula', `Spano', `Cimarron', `Riviera', `Utopia', and `Alabaster'. Superior cultivars adapted to the second market window include `Sweet Perfection', `Sterling', `Vega', `Bravo', `Capri', `Vaquero', `El Charro', `Quest', `Shasta', and `Vision'. `Vaquero', `Sunre 1462', `Sunre 1445', `El Charro', and `Viceroy' have potential for short-term storage for October to December markets.