MODIFICATION CHANGES IN THE PHENOTYPE OF VYDVIZHENEC GRAPE VARIETY UNDER THE INFLUENCE OF NATURAL CONDITIONS ON THE BACKGROUND OF TRADITIONAL AND BIOLOGICAL WAYS OF SOIL MANAGMENT
Modification changes in the phenotype and the norm of reaction in the technical grape variety Vydvizhenec under the influence of natural conditions against the background of traditional and biological ways of soil management have been established. The studies were carried out in the agro-ecological conditions of the moderate continental climate of the south of Russia using modern methods of field research. The average annual air temperature at the research site was 9.7 ºC. During the growing season (May-September) the temperature was 19.9 ºС, during the period of active growth of grape berries (II. June-III. August) - 22.5 ºС, the maximum rose to plus 39.3 ºС, the minimum in the wintering period of grapes dropped to minus 26.7 ºС. The annual temperature range was 54.2 ºC. The drop in air temperature within the day during the growing season was 10.7 degrees Celsius, the maximum - 17.7 ºС. The annual amount of atmospheric precipitation varied from 433 to 866 mm, with a norm of 620 mm. Variations in weather conditions were accompanied by modification variability in the number of clusters, average cluster weight, and grape yield. According to the correlation analysis, the strongest influence was exerted by the minimum air temperature (January-February) on the number of clusters (r = 0.64…0.41) and the average cluster mass (r = -0.67…-0.52), the average temperature in the previous year by the number of clusters (r = 0.65…0.41), the average annual temperature per cluster weight (r = -0.47…-0.35). Atmospheric precipitation as a whole for the year influenced the mass of the cluster (r = -0.38…-0.30). The influence of weather conditions on the grape yield was weak. The reaction norm of the number of clusters was equal 23 against the background of black fallow, 25 - natural grassing-down and 30 pcs/bush - sowing of sour dock, the average weight of the cluster, respectively, 129, 90 and 103 g, the grape yield - 5.79; 5,52 and 6,00 kg/bush.