Indoor growing of tomato with LED lamps and FR bulbs

The indoor hydroponic growing of plants requires the use of different LED lamps, to provide the needed photosynthetically active radiation (PAR); and the crops more efficiently produced with this technology are leafy vegetables and herbs; however, there is a growing interest to produce other important crops like tomato and other fruiting crops under these conditions. Because there is some information that plants also respond to far-red light (FR) with increased size, increased biomass and more flowering; the objective of this research was to evaluate the growth and fruit production of tomato under indoor conditions with LED lamps and FR bulbs. ‘Rio Grande’ tomato plants were established in NFT systems using a nutrient solution recommended for hydroponic vine crops, under 3 different (12 h) lighting conditions: LED lamps only (control), LED lamps + FR (during day), and LED lamps + FR (during night). We had 3 replicates (NFT systems with 2 plants each) per treatment, arranged in a completely random design. Two months later we recorded plant height, leaf length and width, shoot and root fresh weight, and immature fruits per plant. We found the best results in the treatment with LED lamps + FR bulbs (during the day), in terms of plant height (111 cm), leaf length (31.5 cm), leaf width (32.5 cm) and shoot fresh weight (190 g); compared to the control and treatment with LED lamps + FR bulbs (during the night); however, with regard to the number of fruits per plant, the plants with only LED lamps presented the best results (2.5 fruits), followed by those with LED lamps FR bulbs (during the night) (1.5 fruits), and lastly the plants with LED lamps + FR bulbs (during the day) (0.5 fruits).