M. G. DUMITRU1, N. I., VASILE2 and A. BACIU2
1 University of Craiova, Faculty of Mathematics and Natural Sciences, Department of Chemistry, 200585, Romania
2 University of Craiova, Faculty of Agriculture and Horticulture, 200858 Romania
DUMITRU, M. G., N. I., VASILE and A. BACIU, 2016. Using Humic Acids and Vitis vinifera Seed Extract in Decreasing the Thermal Stress on Prunus avium. Bulg. J. Agric. Sci., 22: 391–396
In this paper, the low temperature resistance of some cherry varieties (Kordia, Simone, Regina and Summit) is discussed with a particular emphasis on the method of measuring the electrolytes leakage, the total content of free ions and the peroxydase determined enzyme activity. The aim was to eliminate the negative effects that generate the oxidative stress in cherry by administering a fertilizer based on humic acids and polyphenolic extract from Vitis vinifera seeds. The cherry crop fertilization was done through the “drip” and the foliar system using 10 L ha–1 fertilizer with the “drip” system and 5 L ha–1 with the foliar fertilization. Once the average temperature drops below 0°C, the ion leakage in fertilized plants showed values of 1.06–2.12 times lower than in unfertilized plants. The permeability index value was of 0.14–0.27 in fertilized plants and of 0.15–0.40 in unfertilized plants and the total content of free ions in all varieties of fertilized cherries was smaller. During negative temperatures each fertilized variety responded differently with an increase in the enzyme activity and, at the start of the vegetative activity when the average temperature recorded positive values it was 1.23–1.47 times higher in fertilized plants.