Dynamic changes of blue/red light supply affect yield, biometrical and biochemical characteristics of tomato cultivars

Abstract

The utilization of Light Emitting Diodes (LED) is considered one of the most impacting innovations in modern tomato production systems. The characteristics of artificial light supplied to tomato in greenhouse conditions influence the fruit yield response over the year-round crop cycle. The present work aimed to evaluate the effects of dynamic artificial light application on the growth of two tomato hybrids. The experimental protocol was based on the factorial combination between two artificial light spectra supplied to plants (a spectrum composed of blue 450 nm, red 660 nm with deep pink 400-800 nm as a background, and a white 4000 K light as a control) and two early ripening tomato hybrids (‘Signum F1’ and ‘Meteor F1’). The use of blue/red light-emitting diodes (LEDs) in a growth chamber, accompanied by a gradual increase in the red component during the vegetation phase, significantly enhanced the yield of the two tomato cultivars, with an increase of 1.61 to 1.75 times compared to control plants exposed to white light. Notably, the predominant application of blue LEDs during the early stages of plant development resulted in a reduction in plant height by 1.2-1.5 times. The selected technology involving dynamic adjustments in blue/red light proportions led to a notable increase in chlorophyll and carotene levels in tomato leaves, with enhancements of 1.41-1.46 times and 1.29-1.37 times, respectively. Moreover, the variations in blue/red light demonstrated a significant positive impact on carotenoid accumulation in the fruit, resulting in an increase of 1.29 -1.37 times compared to control plants. The increase in fruit monosaccharide organic acid content in response to blue/red light application resulted in the production of tomato fruit with high taste index and nutritional value, suggesting interesting prospects of this new technology utilization