CRITERIA FOR HARVESTING PLUMS AT THE OPTIMUM MATURITY FOR ROMANIAN VARIETIES OF THE FRESH FRUIT MARKET

Plum breeders and growers from Romania want to improve status of the plums for fresh consumption. Plum fruit quality depends on physical and chemical properties (shape, size, skin colour, bloom, taste and flavor, fruit soluble solids content and acidity, stone adherence), but, also, the optimum time to harvesting for the fresh fruit market. Optimum fruit maturity of plum varieties can be achieved by the fruit colour and firmness. For this reason we have studied seven new Romanian plum varieties (‘Alina’, ‘Carpatin’, ‘Roman’, ‘Pitestean’, ‘Sarmatic’, ‘Tita’ and ‘Tuleu timpuriu’), cultivated in field trial of the Genetics and Breeding laboratory in Research Institute for Fruit Growing Pitesti. Fruit skin color was measured by Konica Minolta chromameter model CR 400 based on the Hunter L, a, b-system. Fruit firmness was measured with non-destructive penetrometer Qualitest HPE equipped with a plunger of diameter 0.10 cm2. In addition to these two criteria were also measured others, such as: fruit size, fruit color and fruit soluble solids content.For statistical analyses DUNCAN test was used. Fruit colour ranged from red (Roman) to dark blue (Piteștean). According to the colour chart CTIFL, plum varieties were classified as group 4 - light blue (‘Alina’, ‘Carpatin’, ‘Roman’, ‘Tuleu timpuriu’) 5 - blue (‘Sarmatic’ and ‘Tita’) and 6 - dark blue (‘Piteștean’). After firmness, varieties were grouped into two groups: group 2 - beginning of maturation (‘Carpatin’, ‘Roman’, ‘Sarmatic’, ‘Tita’, ‘Tuleu timpuriu’) and group 3 - optimal harvest time (‘Alina’ and ‘Piteștean’). Regarding the other criteria, like fruit weight and soluble solids content, it can be said that all studied varieties are suitable for fresh consumptio