Harvest date effects on maturity, quality, and storage disorders of 'Honeycrisp' apples

'Honeycrisp' is a new apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] cultivar that has been planted extensively in North America, but the storage disorders soggy breakdown and soft scald have resulted in major fruit losses. The effects of harvest date and storage temperature on fruit quality and susceptibility of fruit to these disorders have been investigated in Michigan, New York, and Maine. Internal ethylene concentrations were variable over a wide range of harvest dates, and a rapid increase in autocatalytic ethylene production was not always apparent. The starch pattern index, soluble solids content, titratable acidity and firmness also appear to have limited use as harvest indices. Development of soggy breakdown and soft scald is associated with later harvest dates and storage of fruit at temperatures of 0 to 0.5 degreesC compared with higher storage temperatures. It is recommended that 'Honeycrisp' be stored at 3 degreesC, although storage disorders still can occur at this temperature if fruit are harvested late. In addition, greasiness development may be worse at higher storage temperatures.