ORGANIC FERTILIZATION INFLUENCE ON GROWTH AND FRUITING PROCESSES OF THREE APPLE CULTIVARS GROWN IN THE MARACINENI-ARGES AREA

The present paper studied the influence of organic biostimulators and fertilizers, administrated in three applications between 70-75 BBCH, on growth and fruiting processes of three apple cultivars grown in five and six years high-density orchards at the Research Institute for Fruit Growing, Maracineni, Arges (southern part of Romania). During 2020-2021, the increase of the trunk cross-sectional area registered an average of 5.25 cm2 (0.02-21.19 cm2), and the fruit yield averaged 55.64 t/ha (0-166.98 t/ha). The mean values recorded for the fruit weight and pulp firmness, were 173.22 g (74.13-558.76) and 76.50 units Bareiss HPE-II-FFF (53.60-89.10), while the pH of the fruit juice and total soluble solids fluctuated around 3.55 (3.09-4.68) and 13.3 ⁰Brix (9.45-18.20). Foliar treatment with Cifamin BK (1.5 l/plant) significantly increased fruit yield by 49.5% compared to the untreated variant. Fruit weight increased in all three fertilization treatments on ´Decosta Jonagold de Coster´ and ´Red Braeburn´. Organic biostimulators and fertilizers improved pulp firmness on ´Golden Reinders Delicious´, juice pH on ´Decosta Jonagold de Coster´ and total soluble content on ´Red Braeburn´. The results of the study showed that, on the mineral nutrition background, Cifamin BK and Biohumus treatments in apple orchards improved fruit yield and quality.