Growth characteristics of foreign willow (Salix viminalis L.) varieties on leached chernozems of the Central Forest-Steppe

Purpose. To analyze the growth characteristics of six varieties of basket willow plantations over eight years of cultivation in the Right-Bank Forest-Steppe of Ukraine. Establish the optimal age for harvesting biomass. Methods. Field, laboratory, analytical and statistical. Results. Biometric studies of eight-year-old shoots from plantations revealed differences in their height, diameter, and weight. The cultivar ‘Inger’ had the highest values: 6.42 m, 3.3 cm, and 1.76 kg, respectively. The values were slightly lower for ‘Tordis’: 6.25 m, 3.1 cm, and 1.67 kg. The heights of the other varieties ranged from 5.90 m (‘Warm-maz’) to 6.13 m (‘Wilhelm’), the diameters ranged from 1.85 cm (‘Gigantea’) to 2.55 cm (‘Marzencinski’), and the dry weights of the shoots ranged from 0.89 kg (‘Gigantea’) to 1.05 kg (‘Marzencinski’). Dry biomass productivity ranged from 9.55 t/ha (‘Gigantea’) to 36.9 t/ha (‘Inger’). A significant decrease in annual height growth was observed in all the studied cultivars: after five years in ‘Tordis’, after four years in ‘Wilhelm’, ‘Inger’, ‘Gigantea’, and ‘Marzencinski’, and after three years in ‘Warm-maz’. A significant decrease in diameter growth was observed after five years in ‘Wilhelm’, after three years in ‘Tordis’, and after four years in the rest. Conclusions. The first harvesting of biomass from the studied plantations should be carried out at the age of four years, and the subsequent harvesting at the age of three or two years.