Evaluation of intensive plum culture system in the north of Oltenia - Romania

European plum (Prunus domestica L.) is the most grown fruit tree crop in North of the Oltenia region. In order to modernize plum culture new culture systems and technologies are required. A trial consisting in 5 European cultivars ('Andreea', 'Centenar', 'Minerva', 'Tuleu gras' and 'Stanley') grafted on 2 rootstocks ('Mirobolan galben' and 'Oteşani 8') and with two planting densities (1250 and 500 trees ha^-1) was set up in 2004 at UCv-SCDP Valcea. In the 11^th year after planting the cultivars grafted on 'Oteşani 8' (Prunus insititia L.) had 39.2% lower vigor regarding trunk-cross sectional and 24.5% lower crown volume then same cultivars grafted on 'Mirobolan galben' (Prunus cerasifera Ehrh.). The average fruit yield on 9 years was 26.3 t ha^-1 in case of the plum cultivars grafted on 'Oteşani 8' and 20.1 t ha^-1 for same cultivars grafted on 'Mirobolan galben'. In case of the planting system with 1250 trees ha^-1 (4.0 by 2.0 m) the average fruit yield was 23.2 t ha^-1 and in case of 500 trees ha^-1 (5.0 by 4.0 m) was 20.4 t ha^-1. The difference between fruit yields of the two planting systems was statistically significant. There were no major differences between the two planting systems regarding fruit quality.