Features of growth and development of seedlings of woody introducents of the genus Pinus L. in the Stavropol botanical garden

Abstract

Trees and shrubs of the genus Pine (Pinus L.) are of great value for landscaping the urban environment of the Stavropol region. The assortment can be replenished by introducing adapted species. The object of the study was seeds and seedlings of coniferous plants of the genus Pinus L. The purpose of the research is to study the characteristics of seed propagation, seasonal growth and development of seedlings of 17 taxa in the conditions of the Stavropol Upland. Specification of species was carried out using the reference book by D.L. Matyukhin (2021), laboratory germination was determined according to the method of M.V. Rogozina (2013); phenological phases of seedlings were recorded using the recommendations of G.I. Redko (1983). Laboratory germination above 75% was shown by seeds of 3 taxa; germination rate (50-75%) – 3; germination rate (25-50%) – 4; less than 25% – 6 taxa. In field conditions, the emergence of seedlings was noted in the 1st-2nd decade of May in 14 taxa. The transition to a dormant state of seedlings of the 1st year of life was recorded in the second decade of September. The beginning of the growing season for seedlings of the 2nd and 3rd year of life was noted in the 2nd decade of April, the transition to the dormant stage in the 3rd decade of September. Seedlings of the 3rd year of life, depending on the species, had a height from 10.0 to 25.0 cm; root length from 12.5 to 47.0 cm; annual growth from 3.0 to 8.5 cm. During the growing season, the seedlings successively went through all phases of seasonal development. The necessary agro technical measures were carried out in a timely manner. As a result of the research, viable seedlings of 14 species and forms were obtained.