EVALUATING SWEET ONION CULTIVARS FOR SUGAR CONCENTRATIONS AND PUNGENCY

Six onion (Allium cepa L.) cultivars were grown during 2 years to eval uate the effects of environment on bulb quality as measured by sugar a nd pyruvate (pungency) concentrations. Within each year, bulb fresh we ight was not affected by cultivar; however, bulb fresh weights were 36 % higher in a year when most of the rain fell during maximum bulb expa nsion. Total bulb sugar concentration and pungency varied among cultiv ars and years. Pungency was higher and the sugar: pungency ratio was l ower in 'Texas 1015Y' and 'Sweet Georgia' than in 'Dessex', 'Rio Bravo ', 'Hybrid Yellow Granex', and 'Granex 33'. Under low S nutrition, mar ket acceptance of ''sweet'' onion cultivars that vary slightly in nons tructural water-soluble carbohydrates may be assessed more precisely b y the sugar : pungency ratio than by sugar or pungency assessments.