Maturity and Quality of `Delicious' Apples as Influenced by Rootstock

Abstract

A rootstock planting was established with `Starkspur Supreme Delicious' apple (Malus dornestica Borkh.) on nine rootstock near Blacksburg, Va. Five uniformly sized fruit per tree were sampled 1 week before normal harvest and three five-fruit samples were taken at harvest. Rootstock had no consistent effect on the proportion of red surface, which averaged ≈90% Ground color was most yellow for fruit from trees on M.26 EMLA and least yellow from trees on M.27 EMLA, OAR1, and MAC24. Starch was lowest for fruit from trees on MAC9 and (Ottawa) 0.3 and highest from trees on OAR1 and MAC24. Firmness differences were neither large nor consistent and ranged from 71 to 78 N. Soluble solids concentrations (SSC) of fruit were consistently high for fruit from trees on MAC9 and 0.3. A maturity index was calculated from the two harvest samples per year. Data for SSC, starch ratings, and ground color were ranked, and the highest maturity index was for fruit from trees on 0.3, MAC9, and M.26 EMLA.