Commercial varieties of European plums grown in Hungary, a comparison of promising foreign varieties with the widely grown traditional ones

Plum growing is a Hungarian tradition since centuries. Its popularity is founded by its long ripening period and its advantageous fruit characters. Up to the present times, plums for fresh consumption as well as for industrial procession are highly appreciated on the market. At the moment, the National List of Varieties contains 20 varieties of State Registration, 3 of them belong to the Japanese plum species. The majority of the list is Prunus domestica L.), but the round shape is typical for ‘Althann ringló’, ‘Zöld ringló’ and ‘Sermina’ which are named Prunus x italica convar. claudiana (i.e. Raineclaudes). The origin of varieties is variable. Three are considered as Hungarian, the rest German, Serbian, Czech, French, Rumanian, Italian (National List of Varieties 2011). The structure of varieties is changing gradually. There is a tendency to prefer varieties, which are more tolerant to the sharka virus, high yielding and autofertile (self-compatible). The majority is a member of “domestic” group (Kovács, 2009). The plum season lasts in Hungary for almost 3 mounts. The fi rst ripe fruit appears around the end of June, early July by ‘Ruth Gerstetter’. The season is ended by ‘President’ at the mid of September. To the late period belong the varieties with large, fi rm fruits and high soluble solid content (e.g. ‘Stanley’, ‘President’). The picked fruit is easily stored for fresh consumption over several weeks (Surányi, Erdôs, 1998; Surányi, Erdôs, 2006; Szabó, 2001), where the role of new German varieties is decisive (Szabó, 2001; Surányi, Erdôs, 1998; Jacob, 1998, 2002; Hartmann, 1998). For the grower, one of the most important faculties of the variety is the fruit mass. According to literature we may distinguish small (less than 25 g), medium (25–35 g), large (35–45 g) and very large (more than 45 g) categories (Szabó, 2001). However, on the market, the diameter of the fruit is considered. For fresh consumption the large fruit has a diameter of 30-35 mm, the rest ought to have 25–28 mm (Szenci, 2006). Large varieties (mainly in the early season) plums and raineclaudes are sold preferably for fresh consumption. Medium and small fruits are ready for deep cooling and industrial processing, where the high content of soluble solids is highly appreciated (Szabó, 2001). The nutritional value of the plum is due to its chemical composition. Compared with other fruits of the moderate climate, the energy content is considerable (244 kJ/100 g). Carbonhydrates are 10–18%, but the alcohols (like sorbite, xylite) are also considerable. The acid are mediocre (0.5– 1.4%), where malic acid prevails but we may fi nd tartaric, succinic and citric acids too. (Rodler, 2005; Surányi, 2006) Commercial varieties of European plums grown in Hungary, a comparison of promising foreign varieties with the widely grown traditional ones