INITIAL LOW-OXYGEN STRESS OFFERS NO SCALD CONTROL BENEFITS TO STARKRIMSON DELICIOUS APPLES IN 0.7 KPA O-2 STORAGE

In a 2-year study, the benefits and risks of an initial low O-2 stress treatment (ILOS; 0.04 kPa O-2 for 10 days) as a supplement to 1.5 or 0.7 kPa O-2 storage for controlling scald in 'Starkrimson Delicious' a pples (Malus x domestica Borkh.) were evaluated. The fruit were picked from 15 orchards and harvested over five successive weeks to generate a wide range in maturity. Storage in 0.7 kPa O-2 did not adequately c ontrol scald in fruit picked at starch index between 1.0 and 2.1 (10% to 35% scald), but reduced watercore-induced breakdown in fruit picked at starch index greater than or equal to 2.4 (0-9 scale). The ILOS tr eatment gave a statistically significant but commercially nonsignifica nt scald control benefit to fruit held in 1.5 kPa O-2 in 1 year, but n ot to fruit held in 0.7 kPa O-2. ILOS did not increase alcoholic taste , but increased skin purpling in 0.7 kPa O-2-stored fruit from the fin al harvest in 1 year. ILOS decreased flesh firmness in fruit picked at starch index greater than or equal to 1.7 and increased watercore-ind uced breakdown in fruit picked at starch index greater than or equal t o 2.1 in both years.