EVALUATION OF WINTER-RESISTANCE KINDS OF MAGNOLIA L. IN THE CONDITIONS OF THE BIOSTATSIONAR VINNYTSIA NATIONAL AGRARIAN UNIVERSITY
Authors: M. Matusiak
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The most sensitive to temperature changes, especially in winter and spring, are annual magnolia shoots, as evidenced by the formation of frost on plants. Therefore, for the successful introduction of magnolia in the temperate climate of Ukraine, it is necessary to select species capable of restructuring their physiological processes in the direction of increasing cold resistance, which will facilitate their adaptation in new conditions.
The analysis conducted to determine the features of winter-hardy species of the Magnolia genus in the Vinnitsa conditions shows that not all species of the genus can tolerate the climatic conditions of the region, and especially the winter period. According to the conducted observations, the beginning of shoot growth in the magnolia in the conditions of Vinnitsa is observed during the month of April. In species such as Magnolia kobus D.C., Magnolia obovata Thunb., Magnolia acuminata L., shoot growth begins in the first decade of Аpril. In the second decade of April, the growth of shoots of Magnolia Soulangeanа Soul. begins. In the third decade of April – the first decade of May, shoots begin to grow actively in Magnolia tripetala L. The terms of the end of the growth period and its duration vary greatly and depend on the geographical origin and species-specific features of the species, but, mainly, the magnolias introduced in Vinnitsa, finish their increment in length in the II–III decade of September – Magnolia soulangeanа Soul., Magnolia tripetala L. In the species Magnolia kobus DC, Magnolia obovata Thunb., Magnolia acuminata L. shoot growth ends in the third decade of August and the first decade of September.
According to the 7-point Woolf winter hardiness scale, it was found that the highest winter hardiness in the conditions of VNAU biostationary (1 point) is possessed by species such as magnolia (M. obovata Thunb.), Kobus (M. kobus DC) and pointed (M. acuminata L.). Somewhat less winter hardiness is characterized by (2 points) Magnolia Soulange (M. soulangiana Soul.), That is, in winter freezing was less than 50 % of annual shoots, and the damage of annual shoots with low negative temperatures was 3–5 cm. The lowest winter hardiness in biostable conditions UNAU (5 points) is noted magnolia triple (M. tripetala L.), the damage of the plant was up to the level of snow cover (almost 80 % of habitus). Deciduous species of the genus are winter-hardy, but in severe winters, such as Magnolia Sulange (M. soulangiana Soul.), Stellate (M. stellata (Siebold & Zucc.) Maxim.), Flower buds and annual shoots can be damaged. It is also important that with age magnolia increases not only the abundance of flowering, its duration, but also winter hardiness.