Abstract:The tree-growing sector is considered to be an important supplier of food and raw material for industry worldwide. Increasingly competitive decisions regarding international investment in orchards depend on business analysis. This study compares three apple orchards situated in Cluj-Napoca, on the Eastern limits of the Transylvanian Plain, Romania. While the climatic and soil conditions are relatively consistent among the three orchards, the technical and economic results (expressed in hectares) vary due to the use of three different technological systems of apple production: extensive, intensive, and super-intensive. The study compares the life cycle, starting with age of fructification, production level (quantity and quality), costs (investment and production costs-divided into material costs, mechanical costs, human costs, and overhead costs), income, profit (including rate of profit), and investment efficiency: Net Present Value (NPV), Internal Rate of Return (IRR), and Payback Period (PP). It was observed that the most economically efficient technological system in terms of investments is the super-intensive one, with a higher production level, a higher share of Extra Class apples, and a younger age of initial fructification. However OPEN ACCESSSustainability 2015, 7 10522 certain inconveniences of this system-such as a more expensive investment, a higher cost of running the business throughout the year, and a reduced life cycle-cannot be ignored.

The influence of two apple rootstocks (M9 and MM106) on growth and yielding of four apple cultivars ("Pinova"‚ "Topaz", "Florina" and "Golden Reinders") in two culture system was studied. The experiment was placed in a commercial orchard at SC Agroindustriala Cluj-Napoca Romania, planted in 2007, during 2012-2104. In the experimental field some growth parameters (length of annual shoots, trunk cross-sectional area, tree height) and fructification (average yield and productivity index) were observed. The studied cultivars had a different response due to the genetic characteristic of each one and on the other hand, due to the rootstock. The results showed that MM 106 transmit much strongly growth than M9. The longest shoots, in terms of mean values, gave the variants where the cultivars were grafted on MM106 (53 cm) and the shortest (34.4 cm) on M9. The biggest average height of trees were obtained on MM 106 rootstock (290 cm). The smallest average trees height were registered by the variants where the trees were grafted on M9 (239 cm). The biggest average trunk cross sectional area were obtained with the MM106 (102.1 cm2). The best yield was obtained in variant where the cultivars were grafted on M9 (47.03 t/ha). M9 rootstock has controlled the tree size of all cultivars more than MM106 resulting in the lowest TCSA (58.8 cm 2 ) and the highest yield per hectar (47.03 tone/ha) and yield efficiency (925 kg/cm 2 ).

Chemical thinning consists in spraying the trees with different substances. The intensity of chemical thinning depends on the vigour of the tree, the phenophase in which it is done, the type of solution and its concentration. In this study for the chemical thinning the following products were used: Ethrel, 0.01% in concentration, Cosavet 80 DF, in concentration of 5%, Sulphur 80 WG, in concentration of 5% and Sulfomat 80 PU, in concentration of 5%, when 80% of the lowers were open. The study took place in fruit-growing ecosystems Călacea and Steluța, by analyzing 7 varieties of plum, in the