EUROPEAN PLUM (PRUNUS DOMESTICA L.) CULTURAL SYSTEMS TRIAL

European plum culture is changing because of the need to increase production efficiency, fruit quality and deal with the Sharka disease. Depending on the biological material (cultivars and rootstocks), specificity and use of fruit, various cultural systems can be used to enhance productivity, fruit quality and economic returns. Several cultural systems have been tried comparatively: the classical system (trees planted at 6 by 5 m, 333 trees/ha); the intensive system with two densities (trees planted at 5 by 4 m (500 trees/ha) and 4 by 2 m (1250 trees/ha)), and two containerized systems (trees planted in 90-L containers buried in the soil and not buried in the soil and spaced at a density of 1665 trees/ha. The plum cultivars studied were: ‘Andreea’, ‘Minerva’, ‘Tuleu gras’ and ‘Stanley’. Into the 10th leaf the trunk cross sectional area (TCSA) varied from 17.1 cm2 in the case of trees in unburied containers to 250.0 cm2 in the classical system. Plum yields (3 year average) varied from 4.0 t/ha (29%) in unburied container system to 25.9 t/ha (189%) in intensive system at 4 by 2 m planting distances comparatively with the classical system where the recorded average yield was 13.7 t/ha (100%). The intensive systems with densities from 500 to 1250 trees/ha had the highest production capacity. The buried container system was suited mainly for conservation of plum accessions in collections, especially in temperate areas where minimum temperatures during winter drop between -12 to -20°C.