Assessment of the influence of the elements of cultivation technology and other factors on the growing of poplar seedlings

Purpose. To study the peculiarities of growing one-year seedlings obtained from cuttings of four black poplar cultivars in the Central Forest Steppe and the influence of agrotechnical measures and other factors on this process. Methods. For three years, the morphometric characteristics of the seedlings of poplar varieties 'Dorskamp', 'I‑45/51', 'Robusta', and Toropohrytskyi poplar, grown on chernozems of the Central Forest Steppe of Ukraine, were studied. One-year lignified 20, 25 and 30-cm long cuttings were used to obtain seedlings that were planted in two periods: autumn (late November) and spring (beginning of April) in the years 2019–2021. Results. For autumn planting, cuttings of Toropohrytskyi poplar had the highest height. It was, on average, over three years, 178.4 cm when using cuttings with a length of 20 cm, 188.7 cm with cuttings of 25 cm, and 197.0 cm with cuttings of 30 cm. The average height of seedlings of 'Dorskamp' variety ranged from 158.2 up to 170.3 cm, in 'Robusta' from 148.1 to 161.8 cm and in 'I–45/51' from 145.2 to 153.8 cm. Plants of 'Dorskamp' variety had the largest dimensions during spring planting, which ranged from 193.8 to 197.9 cm. The average height of Toropohrytskyi poplar plants was from 151.2 to 173.5 cm, of 'Robusta' variety from 131.9 to 149.1 cm, and of 'I–45/51' from 122.4 to 128.3 cm. At the same time, the plants from the shortest cuttings had the highest height in varieties 'Robusta' and 'I–45/51'. Conclusions. Of the studied cultivars cultivated on leached chernozems, it is primarily advisable to use Toropohrytsky poplar and 'Dorskamp' variety. The first one should be planted in autumn using 30-cm cuttings, and the second one should be planted in spring using 20-cm cuttings. Cuttings of the 'I-45/51' and 'Robusta' varieties should be planted in autumn. Their optimal length is 20 cm. The weight of one-year-old poplar cuttings and the proportion of their root system are most influenced by the time of planting, varietal characteristics and weather conditions of the growing season.