Biomorphobiological Characteristics of the Aromatic Rose Cultivar ‘Festivalnaya’ When Growing in the Southern Coast and in the Steppe Crimea

Abstract

Today, the high demand for rose processing products in the world market determines the need to restore the raw material base of aromatic roses and the development of essential oil manufacture. In the era of the USSR, rose cultivar ‘Festivalnaya’, which was created in the Nikitsky Botanical Garden (NBG-NSC), was one of the most promising for industrial cultivation. Plants of this cultivar are undemanding to environmental conditions and agricultural technologies, grow well on the carbonate soils, resistant to chlorosis, rust, powdery mildew. High mass fraction of essential oil (0.12– 0.14 % of the weight in raw form) and yield (15.8–39.0 centners/ha), as well as high content of phenylethyl alcohol in the essential oil, which was close to the standard - Bulgarian rose from the Kazanlak valley, are distinctive characteristics of this cultivar. For the last 25-30 years, biomorphological studies of plants of this cultivar in the conditions of the Crimea and Russia have not been conducted. The purpose of the research was to study the degree of manifestation of varietal traits of plants of the aromatic rose cv. ‘Festivalnaya’ in different ecological and geographical conditions of the Crimea to determine its genetic stability at conditions of weather and climatic changes in the region. Studies were carried out in 2015–2019 in the collection plantations on grafted plants under conditions of the Southern Coast of the Crimea (SCC) and the Crimean steppe zone according to generally accepted methods. Comparing the obtained data with the literature sources, we concluded that under modern growing conditions, morphological changes affected an increase in the number of thorns per unit of measure (7.18 ± 2.34 pcs., which on average surpasses the literature data by 2.0 pcs.), an increase in the double-flowered trait (on average, there are 95.2 ± 9.0 petals, which is 20 petals more than according to the data mentioned in 1975–1976). The results of phenological observations showed that rose bud swelling in the SCC and steppe Crimea begins in the second half of February when the sum of positive temperatures is above 231 °С and a steady increase in air temperature is above 5.4 °С. Over the past 40 years, the beginning of flowering of the aromatic rose cultivar ‘Festivalnaya’ in the Southern Coast has shifted to an earlier date. The beginning of flowering occurs in the middle/end of May when a certain accumulated temperature is reached (above 1125 °C) and the average monthly air temperature is above +17.5 °C. The period of mass flowering, during which it is possible to collect up to 80 % of the flowers from the total crop, in the Southern Coast lasts 14.4 ± 2.9 days, namely from the end of May to mid-June. In recent years, a tendency to a decrease in the duration of the flowering period of the aromatic rose cv. ‘Festivalnaya’ is observed: the maximum flowering time has decreased and became seven days shorter; the average flowering time – three days shorter. The yield of flowers of grafted bushes of ‘Festivalnaya’ at the age of four to eight years averaged 17.0 centners/ha; the maximum yield reached 24.6 centners/ha.