Response of Hyacinthus orientalis L. to salinity caused by increased concentrations of sodium chloride in the soil.

Hyacinths are used in flowerbed in cities. Plants are exposed to difficult urban conditions prevailing in winter, including notably to soil salinity resulting mainly from the use of sodium chloride. The aim of the study was analysed the response of Hyacinthus orientalis 'Delft Blue' to increased concentrations of sodium chloride in the soil. Pots with bulbs were each treated with 100 cm3 of NaCl aqueous solution at a concentration of either 10 g .dm-3 (dose level 1) or 20 g. dm-3 (dose level 2). Pots were irrigated with the NaCl aqueous solution in September or in January of the following year. After keeping the bulbs at a cool temperature for 12 weeks, the plants were grown in a greenhouse where they were assessed in terms of growth parameters and free proline content. The obtained results showed that the growth and the ornamental qualities of Hyacinthus orientalis 'Delft Blue' after treatment with sodium chloride were sufficient for recommending this plant for growing in flower beds exposed to salinity of 6.1-8.6 g dm-3. The leaf greenness index and proline content (in the second season) were greater and the length of forcing period was longer (in the second season), when the sodium chloride was applied to the soil on the day of planting bulbs. [ABSTRACT FROM AUTHOR]