Fruit Characteristics of ‘Red Delicious’ Apple Strains during Maturation and Storage

Abstract

Abstract Firmness, soluble solids concentration (SSC), starch index, and internal ethylene concentration were measured in the ‘Starkrimson’, ‘Oregon Spur’, ‘Redchief, ‘Royal Red’, and ‘Topred’ strains of ‘Red Delicious’ apple (Malus domestica Borkh) between 130 and 150 days after full bloom (DAFB). Firmness was significantly correlated with DAFB, although there were increases and decreases between 130 and 144 DAFB. SSC increased and was correlated with DAFB. The starch index increased linearly most of the time. There were differences in starch index between the 1983 and 1984 seasons, but no consistent differences among strains. Internal ethylene concentration began to change later than the other characteristics, but was correlated with DAFB in 90% of the comparisons. Fruit attributes that were significantly correlated in 80% or more of the comparisons were firmness with starch index, SSC with starch index, and starch index with internal ethylene. Firmness was correlated with starch index in 90% of the comparisons, SSC in 85%, and internal ethylene in 60%. Superficial scald was consistently correlated only with DAFB. Changes in firmness during storage were not correlated with any of the characteristics measured.