ACHIEVEMENTS AND PERSPECTIVES ON STONE FRUIT GROWING ON SANDY SOILS

Climatic conditions in the sandy soils of southern Oltenia encourage cultivation of tree species in terms of applying specific technologies. Possibility of poor sandy soils fertile capitalization, earliness in 7- 10 days of fruit ripening , high yields and quality are the main factors supporting the development of fruit growing in the sandy soils of southern Oltenia. The main objectives of the research were to CCDCPN Dăbuleni. Establish and improve stone fruit species assortment, adapted to the stress of the sandy soils, establishment and evaluation of the influence of stress on trees and their influence on the size and quality of production, development of technological links (planting distances, forms management, fertilization), getting high and consistent annual production of high quality, containing low as pesticide residues, to establish a integrated health control program of the trees with emphasis on biotechnical. Research has shown good stone species behavior, and their recommended proportion is 75% of all fruit trees (peach 36%, 14% apricot, plum15%, sweet and sour cherry fruit growing 10% of the total area). Results on peach varieties revealed: ’Redhaven’, ’Suncrest’, ’Loring’ with yields ranging from (24.8 t / ha to 29.0 t/ha) with maturation period from July to August, and varieties ’NJ 244’, ’Fayette’, ’Flacara’ with productions ranging from (19.7 t / ha to 23.0 t/ha) with maturation period from August to September. The sweet cherry varieties ’Van’, ’Rainier’, ’Stella’, with yields ranging from 17. 2 to 24.4 t / ha. In the range studied sour cherry were found ’Oblacinska’ varieties of 11.0 t / ha, ’Cernokaia’ with 10.5 t / ha, ’Schatten Morelle’ with 9.1 t / ha. Optimum planting density and shape of the peach crown found that the highest yields of fruit are produced in the form of vertical cordon crown, with values ranging from 15.9 t / ha at a distance of 2 m, 10.3 t / ha at a distance of 2.5 m and 7.9 t / ha at a distance of 3 m, the distance between the tree rows is 4m. Need for organic and mineral fertilization, and the effectiveness of micronutrients with bor established optimum fertilizer doses on fruit peach, (40-60 t / ha manure and N100P80 K100). Biochemical compozition of fruit parameters is comparable with that obtained in other fruit growing areas in the country. Cherry and cherry fruit under sandy soils accumulate much larger quantities of total drymatter, carbohydrates and C vitamin compared with apricot and peach fruit

Investigation on the influence of some natural organic complex fertilizers of boron for increasing the metabolic activity and quantitative and qualitative yield in the peach tree, on psamosols from Southern Oltenia

Natural organic complex fertilizers of boron are bioactive substances, having many biological activities, especially properties of increasing metabolic activity and production. The obtained results in the Redhaven peach variety have shown the favourable effects of treatments on fruit tree growth and development according to the phenological phase and the number of treatments. The chlorophyll content (a+b) has increased once with the number of treatments, while the highest values were obtained at the stage of shoot maturation, at the variant fertilized with complex boron, 5 l/ha, in four treatments (5.99 mg/g fresh matter). The determinations on the NPK content of leaves at the stage of intense shoot growth pointed out better results at the variants treated with natural complex fertilizers of boron, where four treatments were applied (3.06%Nt, 0.64%Pt, 1.63%Kt at the variant treated with complex boron, in four treatments). The DM content of leaves has shown higher values at all the variants where natural complex fertilizers of boron were applied. It also increased once with the number of treatments. The best results were obtained at the variants treated with Cupribor and Boron complex, in four treatments (41.23%). At all the studied variants, the DM quantity accumulated in leaves through photosynthesis was higher at the variants treated with natural complex fertilizers of Boron in four treatments (43.7mg DM/dm2/8h at the variant treated with Cupribor and 47.2mg DM/dm2/8h at the variant treated with Boron complex). As concerns the fruit production, there were significant yield increases at all the variants fertilized with Boron, but the best results were obtained at the variants where four treatments with Folibor (12.2t/ha) and Boron complex (11.5t/ha) were applied. The fruit quality was favourably influenced by boron. The obtained fruits had a higher content of DM, glucose, vitamin C and a lower content of nitrates