Evaluation of growth characteristics of one-year poplar and willow clones in short rotation plantation in Kharkiv region

Breeding and cultivation of poplar (Populus sp.) and willow (Salix sp.) was practiced by many researchers throughout the 20th century. Mostly theirs interests were focused on the long-term period of plant cultivation (up to 20 years) with using the wood in timber or paper-pulp industry. Cultivation of poplar and willow under short rotations (up to 3–5 years) in Ukraine is underestimated. Therefore, for establishing high productive energy plantations, testing of varieties at the early stages is of particular interest. The purpose of our work was preliminary evaluation of growth rates at first-year trials of poplar and willow clones under short rotation cultivation. At the experimental plot in Kharkiv region, 10 poplar and 3 willow clones were planted in 2014. The plants were analyzed in October, after the end of growing season. Measurements of the survival rate (%), shoots’ diameter (cm), their height (m), the average number of shoots per plant, dry biomass weight (g), and general estimation of plants’ state were performed. According to the results, survival rates were differed in different clones and in poplar clones ‘Strilopodibna’, ‘Druzhba’ and ‘Gulliver’ were significantly higher (76–84 %) from the average levels. The lowest survival levels (48–51 %) were found in poplar clones ‘Konstanta’ ‘Roganska’ and willow ‘Pryberezhna’. The studied clones differed by growth rates also. It is worth to mention that poplar ‘Gulliver’, ‘Slava Ukrainy’, ‘Strilopodibna’, ‘Druzhba’ and willows ‘Olympiysky vogon’ and ‘Lisova pisnya’ showed the best growth activity at the first year. The ave­rage growth rates at the end of the first vegetation season were demonstrated by poplar ‘Novoberlinska-3’, ‘Toropogrytskogo’ and ‘Roganska’, while poplar ‘Konstanta’, ‘Lvivska’, ‘Nocturn’ and willow ‘Pryberezhna’ showed the lo­west growth rates.