Post-harvest quality of ‘Green Gage’ European plum in integrated production: effects of year and fruit maturity

Abstract

SummaryThe post-harvest quality of European plum (Prunus domestica L.) ‘Green Gage’ in integrated production was studied over three consecutive production years which varied in climatic conditions and fruit load. In each year, plums harvested at two stages of maturity at harvest, and during storage, were assessed for their weight, skin colour, fruit firmness (FF), total soluble solids content (TSSC), and titratable acidity (TA). The fruit load varied considerably from year-to-year, due to the effects of Spring frosts and biennial bearing. In general, year and harvest maturity affected most of the quality parameters analysed. The year fruit maturity interaction was highly significant only for TSSC at harvest. Changes in quality parameters during maturation and storage varied between years, with different crop loads, since fruit with a similar FF at harvest showed different levels of TSSC, TA, and colour. These parameters, and FF, developed differently during storage, depending on the year. In integrated production, the harvest period could be determined using FF and colour hue angle (hº), a parameter highly and positively correlated with FF at the end of storage. Thus, it may be possible to improve the ‘ready-to-eat’ quality of ‘Green Gage’ European plums at the end of storage, using FF and hº at harvest as selection criteria, regardless of crop load.