THE EFFECT OF HARVEST DATE ON APPLE QUALITY

In the years 1986–1992 storage behaviour of McIntosh apples was studied. Each year, the place of maturation was monitored from 5–6 weeks before expected optimum picking date as determined by the Smith method based on mean night temperatures in a 15 day post bloom period. Several quality and maturity parameters were assessed, among them flesh firmness, % red coloration. starch pattern, soluble solids, titratable acidity, internal ethylene content and induced ethylene production. Based on that, dates of the appropriate early, optimum and late pickings were fixed. Apples were picked at given dates and each lot stored separately. Final quality evaluation and the presence of storage disorders at the end of storage period and simulated shelf life were employed to verify the appropriate picking date decision. The overall best quality retention was observed for apples from optimum and late harvests. Although late harvested fruits had better colour, they were more prone to develop senescence related symptoms in the post storage period.