Chemical and Sensory Properties of Greenhouse Tomatoes Remain Unchanged in Response to Red, Blue, and Far Red Supplemental Light from Light-emitting Diodes

Abstract

<jats:p>In addition to photosynthesis, light is a critical mediator of secondary metabolism in plants, signaling the production of potentially health-promoting phytochemicals and regulating the emission of volatile organic compounds (VOCs) that can alter the sensory perception of a tomato. Light-emitting diodes (LEDs) are a viable way to test the effects of individual wavebands of light and are being quickly adopted by the greenhouse tomato industry. However, studies characterizing the effects of specific wavelengths of light or supplemental lighting on phytochemical content in general are lacking. We hypothesized that enriching the amount of supplemental blue and/or red light that tomatoes receive would positively affect the amount of carotenoids and phenolic compounds that accumulate in tomato fruits through cryptochrome and/or phytochrome-dependent signaling pathways. To test this hypothesis, we compared the chemical and sensory characteristics of tomatoes grown with overhead high-pressure sodium (OH-HPS) lamps to those grown with intracanopy (IC)-LEDs emitting different ratios of red, blue, and far red light. Tomatoes were profiled for total soluble solids, titratable acidity, ascorbic acid content, pH, total phenolics, and prominent flavonoids and carotenoids. Our studies indicated that greenhouse tomato fruit quality was only marginally affected by supplemental light treatments. Moreover, consumer sensory panel data indicated that tomatoes grown under different lighting treatments were comparable across the lighting treatments tested. Our research suggests that the dynamic light environment inherent to greenhouse production systems may nullify the effects of wavelengths of light used in our studies on specific aspects of fruit secondary metabolism.</jats:p>

Cultivation Systems, Light Intensity, and Their Influence on Yield and Fruit Quality Parameters of Tomatoes

“…The cultivation systems-either glazing or additional LED interlighting-did not significantly affect the TA content or the a-value or the hue angle from the fruits but were shown to be cultivar-dependent. Dzakovich et al [39], found that supplementary lighting from red, blue, and far red LEDs did not significantly affect the physiochemical or sensory properties of greenhouse tomatoes. They suggest that fruits that were harvested in a time were solar DLI (daily light integral) contributing substantially to the total amount of the light received by plants, may reduce the effect of supplemental lighting.…”

“…Several studies about different additional lighting or light spectra and their influence on yield or fruit parameters have been published [10,39], but no publication about the effect of single glazing or double glazing on fruit quality could be found. We took a closer look at the factors glazing and supplemental LED interlighting and investigated a variety of parameters that influence taste and aroma, as well as yield parameters, the nutritional value of the fruits, and how they are affected by these two factors.…”

Supplemental LED Lighting Effectively Enhances the Yield and Quality of Greenhouse Truss Tomato Production: Results of a Meta-Analysis

“…Looking at qualitative parameters, while most of the analyzed studies associated supplemental lighting with positive effects (increasing TSS by 6% and Asc by 11%), some inconsistent results were also found. Accordingly, Dzakovich et al ( 2015 , 2017 ) reported that supplemental lighting did not increase the TSS values. Similarly, supplemental lighting on tomato plants was not associated with increased TSS values or Asc contents (Lu et al, 2012b ) or with the sugar or acid contents, according to Gautier et al ( 2005 ).…”

“…The results showed that the highest studied green percentage (39%), which was similar to the sunlight spectrum, showed the best effects on plant biomass and yield, suggesting that plants may use sunlight-combined wavelengths more efficiently for growth than other wavelength combinations (Kaiser et al, 2019b ). The far-red wavelength was also investigated by several studies on greenhouse tomato supplemental LED lighting (Pepin et al, 2014 ; Hao et al, 2015 , 2016 ; Gómez and Mitchell, 2016b ; Song et al, 2016 ; Dzakovich et al, 2017 ; Fanwoua et al, 2019 ; Ji et al, 2019 ; Kalaitzoglou et al, 2019 ; Kim et al, 2019 , 2020 ; Zhang et al, 2019 ). The far-red ratio, particularly the red:far-red ratio, influences phytochrome regulation and has effects on plant architectural development, flower induction, germination, photosynthetic capacity, and nutrition (Demotes-Mainard et al, 2016 ).…”

“…Nonetheless, the high plant density required for these systems can limit light penetration within canopies with consequences on fruit quality and yield (Wada et al, 2006 ). In this context, several studies have already reported the usefulness of LED lighting system applications for qualitative and quantitative improvements in greenhouse truss tomato production (Tewolde et al, 2016 ; Dzakovich et al, 2017 ; Jiang et al, 2017 ; Kim et al, 2019 ). However, inconsistencies among studies are also present; non-significant effects of supplemental LED lighting, especially on qualitative parameters (e.g., soluble solids, ascorbic acid) (Lu et al, 2012b ; Hao et al, 2016 ), have been found.…”