The study of growth of blue honeysuckle sprouts (Lonicera caeruleae L.) in the conditions of North-East of the European Russia

Abstract

The aim of the research is to study characteristics of sprout growth of 13 blue honeysuckle variety samples for evaluation of their viability in the conditions of Kirov region. Recordings and observations were carried out since 2018 to 2020 on the collection area (2017 year of planting). The length of a one-year growth was measured on three even-aged plants of each variety sample ten days after the moment of sprout growing till the end of growth. The length of 20 sprouts of the first-order renewal located according to four corners of the earth, was recorded on one plant. The sprout growth began from the 2nd to the 11th of May. Over the studied time an average duration of a growing period was 49.0 days. The variety Masha was distinguished for maximum duration in 2018 (55 days), the varieties Omega, Lenarola, Goluboy Desert (Blue Dessert), Laura and Dark-Blue № form had the minimal one in 2019 (42 days). Maximum length of the one-year growth was observed for the variety Renata (20.6±4.1 cm), Goluboy Desert (Blue Dessert) (20.8±5.2 cm) and Malvina (25.6±5.7 cm). The analysis of the dynamic of sprout growth showed that in the conditions of the studied period the maximum growth was observed in the first (33.8 %) and in the second (35.3 %) decades of growth – approximately, from the middle of May till the first decade of June. The decrease in intensity of sprout growth was noticed in the third decade – an average growth was 21.2 % (from 14.2 % in 2018 to 28.8 % in 2020). The fourth and fifth decades were characterised by fading of growth processes – intensity of growth was 5.9 % and 3.9 %, respectively. The contribution of the secondary growth to an annual growth did not exceed 26 % for Lenarola variety and 20 % for Goluboy Desert (Blue Dessert). The varieties, which had Turchaninov honeysuckle (Lonicera turczaninowii Pojark.) in their breeding record, did not differ in intensity and duration of sprout growth from the descendants of Kamchatka honeysuckle (Lonicera kamtscatica (Sevast.) Pojark.). An obconical shape of the bush prevailed among the studied variety samples (6 varieties or 46.2 %). All the studied variety samples of honeysuckle showed high viability in the conditions of the Kirov region.