Plant Growth of Curly Kale Under Salinity Stress

Ornamental plants growing in urban areas are exposed to soil salinity that negatively affects their quality. Identifying species that retain high ornamental value despite salt stress is therefore of high practical importance. Curly kale (Brassica oleracea L. var. sabellica L.) is an attractive plant with leaves of both edible and ornamental character. The aim of the study was to evaluate a response of ornamental curly kale to different concentrations of NaCl. The study material was ‘Scarlet’ cultivar. The plants were grown in pots in a plastic tunnel. They were irrigated with NaCl solution at the following concentrations: 50, 100, 200, 400, and 800 mM mmol·dm-3. NaCl treatment resulted in a significant increase in pH and electrical conductivity (EC) of the substrate. Salt stress significantly affected plant growth and number, width and length of leaves, and the effects depended on NaCl concentration. Fifteen days after the salt supply ceased, relative chlorophyll content in leaves (SPAD) decreased due to NaCl treatment in a concentration-dependent manner. Treatments with 200, 400, and 800 mmol·dm-3 NaCl reduced stomatal conductance, and the changes were greater on the 5th day following the stress cessation than on the 15th day. Irrigation with a 200, 400, and 800 mmol·dm-3 NaCl solution negatively affected plant bonitation score. The plants treated with 50 i 100 mmol·dm-3 NaCl were not significantly different visual score from the control plants.