Tomato Cultivation in a Plant Factory with Artificial Light: Effect of UV-A Irradiation During the Growing Period on Yield and Quality of Ripening Fruit

Dwarf cherry tomatoes ‘Red Robin’ and ‘Tiny Tim Red’ were cultivated in two sections. The sections set as (1) section irradiated only by fluorescent lamps (main wavelengths 433, 543, 610 nm; 230 μmol·m−2·s−1 of photosynthetic photon flux density) non-treated with UV-A irradiation (hereafter, non-UVA), (2) treated (maximum peak emission: 352 15.1 W·m−2 ultraviolet radiation intensity; hereafter, t-UVA). fruit weight per plant the number fruits not significantly affected cultivar or section. Regarding quality, cracking rate was lower t-UVA than non-UVA There no anatomical histochemical differences structure distribution pigments such lycopene β-carotene, but shape pigment epidermal cells needle-shaped unclearly-shaped t-UVA, so different between In addition, layers hypodermis exocarp that accumulated smaller Fruit components showed increased total soluble solids (TSS), titratable acidity (TA), ascorbic acid content, a decreased carotenoid content. Therefore, it shown had positive effect on TSS, TA content negative size UV did affect yield plant. Comparing Red’, there significant difference yield, larger, while component higher Robin’. conclusion, when cultivating tomato plants factory, further improvements composition are expected appropriately adjusting time intensity for each cultivar.