Effects of LED supplemental lighting on yield and some quality parameters of lamb's lettuce grown in two winter cycles

Chemical composition and antioxidant activity of Cichorium spinosum L. leaves in relation to developmental stage

“…In contrast, according to Lin et al (2013) sugar content is an important quality feature of lettuce leaves. In the same study and the study of Wojciechowska, Dugosz-Grochowska, Koton, and Zupnik (2015), sugar content in lettuce and lamb's lettuce leaves, respectively, was significantly affected by light quality and intensity, while Wojciechowska et al (2015) have also observed a significant positive correlation between sugars content and fresh weight of rosettes, which was also the case in our study. Furthermore, sugar composition changes during plant development have been also observed in lettuce plants, with sucrose being the main reserve sugar prior to anthesis, followed by lower molecular weight sugars such as glucose and fructose (Lee & Sugiyama, 2006).…”

The Impact of Spectral Composition of White LEDs on Spinach (Spinacia oleracea) Growth and Development

“…In fact, as stated above, it emits a higher percentage of red wavelengths than blue wavelength and, consequently, can correctly stimulate the photosynthetic photoreceptors. The datum is consistent with the literature which has investigated the correct blue/red ratio in the SPD of lighting for obtaining the best plant response in terms of photosynthetic and physiological systems: previous studies demonstrated, indeed, that lettuce and cucumber spectral demand is only 10% of blue and 90% or less of red wavelengths [5,21,28].…”

“…Additionally, the existence of a relationship between the chlorophyll concentration and the nitrate status in leaves has been demonstrated [40]. In several studies the effect of the light spectral composition on the concentration of chemical elements has been investigated; LED lighting containing a small percentage of blue, and a high percentage of red, wavelengths produces elevated sugar and phenol contents in lettuce, but also reduces the presence of nitrate; no effect has been found on antioxidant elements in basil [14] and on ascorbic acid [28] and protein in lettuce [30]. The concentration of chemical elements in edible leaves is very important for the nutritional quality of vegetables.…”

“…In [28] the optimal growth of lettuce was obtained with the spectral composition containing 90% red light and 10% blue light: with respect to different percentages and HPS control conditions, this spectral composition caused a higher weight and dry matter, soluble sugar content, and phenol production. In another work basil plants showed the best performance when the blue component in the lighting is higher than the red one (ratio 0.7); in this condition the leaf yield was at a maximum and the fresh weight decreased proportionally with the decreasing of the blue percentage in the spectrum [14].…”

Successive harvesting affects yield, chemical composition and antioxidant activity of Cichorium spinosum L.

“…However, the same trend was not observed during the 2nd growing period, where glucose, trehalose and total sugars content increased at the second harvest. The higher sugars content in the 2nd growing period of the present study could be attributed to higher light intensity and consequently to higher photosynthetic and biosynthetic rates comparing to the 1st one (Wojciechowska, Dugosz-Grochowska, Koton, & Zupnik, 2015), since leaves were harvested according to rosette's size and not according to growth stage. Moreover, Poli et al (2002) have reported a significant variation in total sugar content during cultivation and between inner and outer leaves of C. intybus.…”