Наукові праці Лісівничої академії наук України (Jun 2021)
Sowing qualities of Pinus sylvestris L. seeds in forest stands of the western re-gion of Ukraine
Abstract
To analyze the indexes of the Pinus sylvestris L. seeds sowing qualities in the conditions of the western region of Ukraine (Ivano-Frankivsk, Lviv, Ternopil regions), the results of the analysis of the sowing qualities of tree species seeds were used. This analysis being performed in the Lviv Forest Seed Laboratory. During the period 2010-2020, the forest seed laboratory analyzed average sam-ples representing 488 homogeneous lots of Scots pine seeds with a total weight of 6.4 tons. Annually, on average, 41-45 homogeneous seed lots were formed with an average lot weight of 12.2-14.1 kg. The weight of homogeneous lots is characterized by significant variability, which can be explained by the periodicity of seed production of the pine, weather conditions during the period of pollination and seed ripening, a limited number of facilities at a permanent forest seed base, and varying demand for seeds of tree species in certain years. In years with different seeds yield the minimum weight of homogeneous lots of seeds ranged from 1.0 to 2.0 kg, the maximum weight was 50 kg with an average value of 9.8-20.7 kg. In addition, the total weight of homogeneous lots of pine seeds during the study period varies significantly (409-868 kg), which is primarily due to the peri-odic nature of specie seed production, as well as weather conditions in a particu-lar year of the study. Usually, the maximum volumes of pine seeds are harvested in a good harvest seed year, after which the volumes of its harvesting decrease due to both the onset of non-seed years and due to the presence of a significant supply of seeds which are kept for 3-4 years with practically no loss of germinate capacity. The weight of homogeneous lots of seeds also correlates with the quan-tity of the lots - from 31 to 65 pieces annually. Homogeneous lots of Pinus sylvestris seeds during the study period are characterized by a high purity index (Xmid = 96-96.5%) with the minimum val-ues of individual variants being 90.5-91.0%. The average values of 1,000-seed weight (TSW) remain rather high and very similar (7.0-7.1 g) with the minimum values of individual variants 5.1-5.9 and maximum values of 8.4-9.0 g with a very high accuracy of the experiment. The average value of the seed germinate energy of Pinus sylvestris is 69.1-77.2%, however, in all cases, there is a significant variability of this characteris-tic, indicating the heterogeneity of the seed material due to its harvesting at differ-ent forest seed sites, different storage periods and different treatment technolo-gies. The average value of technical seed germinate capacity is 86.3-90.9% with a clear tendency towards increased germinate capacity over the past four years. The relationship between the values of 1,000-seed weight and the seed ger-minate capacity has not been identified: low germination can be inherent in both small- and large-size seeds. Only for seeds with a germinate capacity of 85%, there was observed the largest number of 1,000-seed lots that had the weight of more than seven grams. Among 488 homogeneous lots, seeds of quality classes I, II, III are distrib-uted as follows: 37, 50, and 11%, respectively; the proportion of substandard seeds among the studied homogeneous lots is only 2%. As a whole, in the forest stands of the western region of Ukraine, Pinus syl-vestris produces high quality seeds, which ensures the successful cultivation of this valuable native species into forest plantations.
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