The test material were rooted cuttings of petunia (Petunia x atkinsiana) “Dark Red”, planted on 16th of April in pots P11 in standard peat substrate. The experiment was continued until 28th of June 2019. The plants, leveled in height and quality, were separated into 4 combinations and placed in a grow room in a constant temperature of 20°C. In each combination 15 plants were placed. The following parameters were measured in 6 periods (from 16th of April to 28th o June): height of plant, number and surface area of leaves, number and diameter of flowers, diameter of plants. The source of light consisted of LED lamps by a PLANTALUX. The results were compiled statistically using one-way ANOVA1, and the means were compared using LSD test at P=0,95.
Research was conducted by DSc (habilitation) Agata Jędrzejuk from Department of Ornamental Plants od Warsaw University of Life Science in Warsaw, Poland.