frost resistance, shoots, scale, damage index, bark, cambium, wood, core.

Abstract

Aim. The article aimed at investigation of low temperatures affects features on lavender (Lavandula angustifolia Mill.) cultivars of different ages to determine the possibility of the spread of crop areas in the soil-climatic zones of the Forest-Steppe and Polissya of Ukraine. Methods. The influence of low temperatures on the structural parts of shoots of lavender plants of narrow-leaved cultivars ‘Prima’, ‘Record’ and ‘2-56’ grown in the conditions of the Forest-Steppe of Ukraine in the collection nursery of the Institute of Horticulture of the National Academy of Sciences of Ukraine is analyzed. Critical temperature indices (–25ºC and –30ºC), determined by three-year studies on the structure of lavender plants of the green bark (bark, cambium, wood and core). Results. It was found that one-year shoots were the most damaged by low temperatures – from 2.5 to 4.5 points on a 6-point scale, the least – two and three-year from 0.8 to two points. The most resistant to low temperatures in the average of three years of research were plants of sample ‘2-56’, which had been transferred to the State cultivar testing under the name ‘Mriya’, which total damage rate reached 11.3%. The record-resistant plants were the least resistant to low temperatures, indicating their low adaptive capacity to uncharacteristic growing conditions. The –30ºC temperature regime on the structural units of two- and three-year-old ‘Prima’ and ‘Mriya’ had the most significant negative impact. The objects of research were the most damaged by low temperatures of bark and cambium – up to 3.5 points. The smallest core – up to 2.5 points was seen (except for the ‘Record’ cultivar, all structural units damaged up to 4.5 points). It has been determined that the frost resistance of narrow-leaved lavender plants was a high-grade genetically fixed trait that could be improved as a result of breeding work. Conclusions. The research shows that the structural units of the plants of all the cultivars that were in the experiment did not reach the damage index 400, which destroys the plant, as well as the mark 100 for individual structural units, indicating less or more endurance of narrow-leaved lavender plants under the conditions of forest-steppe cultivation in the Kyiv region. According to the research, the cultivars ‘Prima’ and ‘Mriya’ could be recommended for introduction in the Forest-Steppe of Ukraine, as well as the Polissya zone. ‘Record’ cultivar plants could be used as a source of high levels of decorative and essential oil content.