PECULIARITIES OF THE ONTOGENESIS OF HYSSOPUS OFFICINALIS L. PLANTS IN THE CONDITIONS OF THE SOUTHERN STEPPE OF UKRAINE

Abstract

Purpose is to investigate the biological features of the growth and development of Hyssopus officinalis L. plants in the conditions of introduction. Methods. The experimental part of the work was carried out at the State Enterprise "Experimental Farm "Novokakhovsʹke" of the Institute of Climate Smart Agriculture of the National Academy of Agriculture Sciences, which is located in the first, northern agro-climatic district of the Kherson region. The Nikits`kyi bilyi hyssop variety and hyssop forms of H. officinalis f. roseus and H. officinalis f. coeruleus served as material for research. The forms were isolated from the seed population of medicinal hyssop. Plants were subjected to ecological and phenological observations and biometric measurements according to generally accepted methods. The 4 phases of plant development in the annual cycle with corresponding subphases were studied: vegetative phase, budding phase, flowering phase (beginning of flowering, full flowering, fading), fruiting phase (beginning of fruit formation, beginning of insemination, insemination). The phases in which the most active plant growth occurs have been established. Results. In the conditions of the Southern Steppe, Hyssopus officinalis plants reach 70–80 cm in height, 100–130 cm in bush diameter. The stems are four-sided, woody at the base. There are up to 100 flowering shoots in the bush. In experimental plots where seeds are sown in spring (first-second decades of April) to a depth of 1.0–1.5 cm, seedlings appeared after 14 days (in years with a dry spring, seedlings can appear after 20–25 days). Laboratory seed germination is high (95–97%), and field germination is 75%. When studying the growth dynamics of medicinal hyssop, it was established that the maximum growth of plants is observed in the phase of budding and in the phase of the beginning of flowering. Then plant growth almost stops. The duration of the growing season is 195 days on average. Findings. The development of medicinal hyssop plants in the conditions of the Kherson region occurs without complications. All phases take place in accordance with the biological characteristics of the plant. The maximum growth of plants occurs in the phase of budding – the beginning of flowering. It was also established that under the conditions of introduction, plants go through all phenological phases of development and produce full-fledged seeds with high germination.