A closed system for plant production with artificial light is an innovative method of plant cultivation. By placing plants on shelves, higher  space efficiency is achieved and costs of heating are reduced as compared to greenhouse cultivation. The aim of the study was to assess the influence of light colour and type of lamps on the quality and nutrient status of chrysanthemums (Chrysanthemum x grandiflorum Ramat./Kitam.) cultivated in a growth chamber with no access to natural light. Two-factorial experiments were conducted: (factor A: lamp type: LED and fluorescent, factor B: light colour: Red (denoted as R), Blue+White (B+W), Red+Blue (R+B); Green (G); White (W), Blue (B). For all colours the quantum irradiance was 35 μmol·m-2·s-1 and the day length was 10 hours. The plant growing  experiments were conducted in a controlled environment growth room. Measurements and observations were carried out at anthesis when 50% of all flower heads were completely developed. The measurements referred to plant features determining plant quality, i.e. the number of flower buds and flower head, diameter of flower head, height and diameter of plants, index of leaf greenness (SPAD). Plant quality was significantly dependent on light colour and the type of lamps used. Earlier flowering of plants was observed under LED lamps emitting white and blue light. The largest flower heads were produced by plants grown under blue and red + blue colour light. Red light emitted by both types of lamps had an adverse effect on plant flowering. Both the type of lamps and the colour of emitted light significantly modified the plant nutrient status. Interactions between the studied factors were found. The mean content of nitrogen, phosphorus, calcium, magnesium and sulphur was higher in plants grown under LED than FL lamps. A similar trend was also found for the microelement content.

22.3.2017