Dynamics of growth processes and decorative state of <i>Miscanthus sinensis</i> during introduction in the steppe zone

Abstract

Relevance. Miscanthus sinensis Andersson is one of the most popular cereals in ornamental gardening around the world. It can be used to decorate the shores of reservoirs, in rocky gardens, rockeries, mixed borders, as a solitaire on the lawn, to create decorative group plantings in gardens, parks, squares. The objective of the paper is to study the dynamics of growth processes and the decorative state of Miscanthus sinensis varieties during the growing season in connection to the thermal resources of the southern steppe zone of the European part of Russia.Methods. Processing of the results of phenological observations, calculation of the sums of effective temperatures and mathematical processing were carried out according to standard methods.Results. The results of a study of 13 varieties of Miscanthus sinensis are presented. It is shown that during the growing seasons 2019–2021 they preserve rhythmic processes similar to natural ones. The beginning of vegetation came on 12–17.04 and the completion of growth processes in the flowering phase in earlyflowering varieties — on 5–12.08, medium-flowering — 16–22.09, late-flowering — 12–18.10, when the sum of effective temperatures for the period of the flowering phase had reached in 2019 — 1059.8–1585.7°C, in 2020 — 1026.5–1638.8 °C, in 2021 — 1063.75–1437.0°. Generative shoots of early and mediumflowering varieties reached 60–80% of the final linear size by mid-June, with the development of up to 60–70% of leaf blades, and by mid-July — 80–90% (170–200 cm) and looked decorative due to the shape of the bush and the decorative state of the leaves, which by this time had developed by 75–90%. Dynamic indicators of linear growth of generative shoots correlate with the sum of the effective temperatures of the growing season: in 2019 — r = 0.93–0.96; in 2020 — r = 0.85–0.9, in 2021 — r = 0.90–0.92.