Effect of High Pressure Sodium and Light-Emitting Diode Lamps’ Supplementary Lighting and Diffusion Glass on Growth, Yield, and Fruit Quality of Pink Tomato

In this study, for first time, the efficiency of the yield and fruit quality of the pink tomato cultivar ‘Tomimaru Muchoo’ was studied in hydroponic cultivation with top and interlighting with LEDs (light-emitting diodes) and diffusion glass ( DGlass ) to cover the glasshouse roof (LED+LED+ DGlass ). DGlass was also tested in tomato cultivation with only top lighting by sodium lamps (HPS+ DGlass ). The control, which had no DGlass (HPS, high-pressure sodium), was a crop with sodium lamps from above, where the roof was covered with conventional glasshouse glass. Selected parameters of tomato plant growth and development, photosynthetic activity, and chemical composition were analysed. Tomato fruits were evaluated for their physical and chemical characteristics as well as sensory quality. LED+LED+ DGlass -supplemented tomato plants had the shortest fruiting stems, a higher dry matter of leaves, higher Mg 2+ ion concentration, and photosynthetic apparatus activity (PI, PSII performance index) compared with the control (HPS). More light under DGlass conditions with and without LEDs (HPS+ DGlass and LED+LED+ DGlass ) increased the tomato leaf thickness and number of mesophyll layers. The highest tomato fruit yield was obtained in the LED+LED+ DGlass combination compared with the conventional growing technology (HPS). Fruits from this combination were characterised by the highest total soluble solids (TSS), carotenoids, and ascorbic acid content and the most favourable sugar/acid ratio. In the sensory evaluation, these fruits were sweeter and less acidic than fruits from the other crop combinations. The results obtained confirm the significant influence of light quality on plant growth, development, and yield.