The effect of far-red light on the productivity and photosynthetic activity of tomato

Annotation It is known that far red light is not a source of photosynthetic energy, but affects the adaptation and development processes of plants. Most of these studies are conducted on young plants, but it is important to understand how high-beam light affects the biochemical composition of tomato fruit, which determines the taste and useful properties. The effect of long-range red radiation on the morphological and biochemical parameters of a tomato plant grown under artificial irradiation with LEDs with a different ratio of red and long-range red radiation from 2 to 9 with the same spectral composition in the range 400÷700 nm was studied. The intensity of photosynthesis was assessed by the content of photosynthetic pigments, and the biochemical analysis of tomato fruits included the determination of the concentration of nitrates, ascorbic acid, monosaccharides, and dry matter. It was found that long-range red radiation reduces the stress effect of blue led light, which is expressed in a lower concentration of anthocyanins in tomato leaves. Additional long-range red in the spectrum of LED R26 G81 R93 FR49 mmol/m2 s increased the yield of tomato plants 'T-34' F1 by 60% compared to HPS, and by 16% compared to led irradiation without the use of additional long-range red (R26 G80 R94 FR10 mmol/m2 s). The dry matter content in tomato fruits increased by 8-10%, while the number of fruits per plant increased by 42% compared to HPS and by 21% compared to led irradiation without the use of additional long - range red. The content of monosaccharides in tomato fruits 'T-34' F1 in the variant with the use of additional long-range red is 20% higher compared to HPS, and 2 times higher than this indicator compared to LED without the use of additional long-range red irradiation. The use of additional long-range red radiation improves the appearance and nutritional value of tomato fruits.