The influence of planting density on fruit properties and yield of plum table cultivars | Uticaj gustine sadnje na osobine ploda i prinos stonih sorti šljive

The studies were conducted over the two-year period (2008-2010) at Fruit Research Institute in Čačak (Serbia). The trial included three plum table cultivars: Čačanska Rana, Čačanska Lepotica and Čačanska Najbolja. The studied cultivars were grown in five planting densities: I - 4.0 x 1.0 m (2,500 trees/ha); II - 4.0 x 1.5 m (1,666.6 trees/ha); III - 4.0 x 2.0 m (1,250 trees/ha); IV - 5.0 x 3.0 m (666.6 trees/ha) and V (control) - 5.0 x 4.0 m (500 trees/ha). The studies encompassed the following parameters: size and weight of fruit and stone, flesh ratio, stalk mass and length, soluble solids content and yield per tree and unit land area. In the initial cropping, differences in size and weight of fruit and stone, flesh content, stalk mass and length and soluble solids content in fruits were not considerable among cultivars in planting densities of treatment. The average fruit weight in Čačanska Rana was the lowest in IV (41.3 g), and the greatest in V treatment (48.6 g); in Čačanska Lepotica, fruit weight was lowest in IV (32.6 g), and greatest in III treatment (39.9 g); in Čačanska Najbolja values of the same parameter was lowest in II (38.4 g), and highest in I treatment (44.3 g). Yield per tree and unit land area had highly significant differences among planting densities treatments, which depended on planting distance and number of trees per unit land area. The highest yield in all the studied cultivars was realized in the first (I) treatment at planting distance 4.0 x 1.0 m (2,500 trees/ha), whereas it was lowest in the fifth (V) treatment 5.0 x 4.0 m (500 trees/ha). The obtained results confirm the observed regularity that the increase in number of trees per unit land area results in the increase of yield. From the aspect of cultivars used, the highest yield per tree and unit land area in all the treatments were recorded in cultivar Čačanska Lepotica, followed by Čačanska Najbolja, whereas they were lowest in Čačanska Rana.