Evaluation of developmental parameters of tomato seedlings (Solanum lycopersicum) due to various LED light quality

The light is an essential energy source and one of the most crucial factors influencing development of plants. Usage of LED light in cultivation as an artificial light may be beneficial for growers and consumers as well, up to low power consumption high quality of obtain product. Positively affect photosynthetic system efficiency; results in stimulating plant growth increase content of fresh and dry matter and leaf area. LED-lamps allow promoting or inhibiting the growth of stems, number of leaves and roots and, as well flowering control. The objective of current study was to evaluate influence various percentage of blue and constant red light in diode lighting: different ratios B:R light (blue LEDs 12.5%, blue LEDs 25%, red LEDs, mix LEDs and HPS-lamps) with 150-200 µmol m^-2 s^-1 light intensity, on developmental parameters of tomato 'Komeett' F₁. The research was carried out in 2013-2014 in the experimental greenhouse of Warsaw University of Life Sciences. Interim six weeks period of seedlings production measurements and observations were conducted. The experiment showed that every type of lighting significantly affected efficiency of photosynthesis and developmental parameters of plants in diverse level. Red LEDs, blue LEDs 25%, and mix LEDs influenced weight of plants. Leaves from mix LEDs treatment had significantly highest values, opposite to HPS-lamps, which was precisely lowest. Treatments red LEDs and blue LEDs 25% also positively influenced weight of raw material. Application of HPS-lamps and blue LEDs effectively influenced photosynthetic activity (5.88 and 3.00, respectively) of tomato plants. Collected data show that combination of blue wavelengths (12.5, 25 and 50% in mix LEDs) improves amount of chlorophyll pigment determined in SPAD units 36, 40.3, 41, respectively.