THE STUDY OF THE FLOWERING TIME VARIABILITY OF THE SCOTS PINE CLONES AT SCOTS PINE SEED PLANTATION IN THE STATE FOREST ENTERPRICE DUBRAVA REGIONAL DIVISION PAGELEZIAI FOREST DISTRICT

Abstract

The study was conducted in a scots pine (Pinus sylvestris L.) seed forest tree plantation, where the phenological characteristics of the plus tree clones planted in the plantation were studied. The main task of the study is to evaluate synchronicity of the crossing of the studied clones. Thus, the development of vegetative and generative buds was assessed in spring and early summer. In autumn, the abundance of pine cones from those trees and the angle of inclination of the branches were studied. Also, three early and three late clones were selected according to the intensity of development, and 3 pine cones were harvested from each tree for extraction. Then the extraction was finished, the color of the seeds was assessed: light, medium, dark. It was found that significant differences prevailed between clones up to the most important stages at the beginning, mainly due to the statistically significant influence of the origin of the clone. It was also found that the majority of ramets had a very low yield of pine cones and an intermediate branch tilt angle. Also, the receptive stage of female strobils was related to the abundance of the pine cone harvest and the fullness of the seeds. Clones, whose receptive stage started later and lasted for a shorter time, had larger empty (light) seeds.