FACTORS AND TIME OF SAMPLE COLLECTION FOR CORRELATING STORAGE POTENTIAL OF MCINTOSH, SPARTAN, AND GOLDEN-DELICIOUS APPLES

A study was undertaken to identify key factors associated with storage disorders in three commercially important apple cultivars in British Columbia and to determine holy early in the season associations could be measured. Fruit mass, density, and concentrations of N, P, K, Ca, M g, and dry matter were determined for 'McIntosh', 'Spartan', and 'Gold en Delicious' apples (Malus x domestica Borkh) from approximate to 30 commercial orchards 9, 6, 3, and 0 weeks before harvest. Storage sampl es were collected at commercial harvest and evaluated for the developm ent ofinternal breakdown ('McIntosh' and 'Spartan') or bitter pit ('Go lden Delicious') after 1 and 6 months of 0 degrees C air storage. Mass and [Ca] and the mass/[Ca] and [K]/[Ca] ratios were the factors most often significantly correlated with storage disorders within each year for all three cultivars. Correlations were as frequentlysignificant 6 and 3 weeks before harvest as they were at harvest. Mass of 'McIntosh ' and 'Spartan' was the only variable consistently related with breakd own in all 3 years of the study. There were no variables with a consis tent relationship to bitter pit in 'Golden Delicious'. Fruit [Ca] was associated with the relative levels of disorders within years but coul d not be associated with specific levels of disorders across all years .