PUNGENCY AND SUGARS OF SHORT-DAY ONIONS AS AFFECTED BY SULFUR NUTRITION

Sixteen short-day onion (Allium cepa L.) cultivars with high (4.0 meq liter(-1)) and low S (0.1 meq liter(-1) fertility were evaluated for several characteristics associated with bulb flavor. Sulfur levels interacted with cultivars in influencing bulb pungency and concentrations of S and individual sugars, except for fructose. Enzymatically formed pyruvic acid correlated poorly with bulb S concentration, which suggests differential partitioning of S into flavor and nonflavor compounds among cultivars. Bulb percent dry weight correlated negatively with bulb S concentration. Since poor correlations were found between enzymatically formed pyruvic acid and water-soluble carbohydrates, we postulate that pungency and sweetness function independently in bulbs of fresh-market short-day onion cultivars.