Influence of tree age and environmental factors on the internalopopulation variability in nursery germination of service tree (Sorbus domestica L.) seed and morphological properties of bare root seedlings (1+0)

Fruits of service tree were harvested in the fall of 2018 on 10 trees in the area of Tounj. The aim of the study was to determine the age of the trees and the environmental factors on seed germination of seed and morphology of bare root seedlings 1 + 0. To determine the age of the trees and the dendroecological analyzes, increment cores were taken with the Pressler drill bits. On each individual tree were taken two opposite increment cores on the chest height (d1.30). After the collection of the increment cores, standard processing and mechanical preparation of the samples were made. Prepared samples after processing were lens out using ATRICS system and then processed and analyzed with dendrochronological programs. The values of width of both late and early wood were measured. Chronologies of width of the tree rings are standardized using the RCS method and correlations with climate factors (air temperature and precipitation) have been made. The number of seeds in 1 gram ranged from 21 to 41 pcs, depending on the tree. Prior to stratification the seed was moistened for 24 h in distilled water at room temperature. Seed stratification at a temperature of 3°C was duration for 109 days. As a stratification medium, wet sand (ratio of seeds and sand 1: 4) was used. The sowing was done in ranks in Dunemann's bed 02.04.2019. Seeds from each tree were sown separately and quartz sand was used as a substrate for covering. In the period from 17.04. to 16.05, every week, counting the seed germination. As a counting criterion, there was a cotyledons over the surface of the substrate. The total nursery germination varied with respect to the tree and ranged from 12.27 to 59.11%. From sowing to the end of germination, regular plant care was performed in the Dunemann's bed, which included the protection of damping off of seedlings, which was performed on three occasions with Cuprablau Z, Dithane M-45 and Captan WP 50 fungicides. At the end of the vegetation, the height (cm) and the diameter of the root plant root (mm) were measured.