Increasing the performance of cucumber (Cucumis sativus L.) seedlings by LED illumination

Abstract

Light is one of the most important limiting factors for photosynthesis and the production of plants, especially in the regions where natural environmental conditions do not provide sufficient sunlight, and there is a great dependence on artificial lighting to grow plants and produce food. The influence of light intensity, quality, and photoperiod on photosynthetic pigments content and some biochemical and growth traits of cucumber seedlings grown under controlled conditions was investigated. An orthogonal design based on a combination of different light irradiances, ratio of LEDs and photoperiods was used. Treaments consisted of three light irradiance regimes (80, 100, and 150 µmol m−2 s−1) provided by light-emitting diodes (LEDs) of different ratios of red and blue (R:B) (30:70, 50:50, and 70:30) and three different photoperiods (10/14, 12/12, and 14/10 h). The white light was used as a control/reference. Plant height, hypocotyl length, stem diameter, leaf area, and soluble sugar content were highest when exposed to LM9 (150 µmol m−2 s−1; R70:B30; 12/12 h) light mode, while the lowest values for the above parameters were obtained under LM1 (80 µmol m−2 s−1; R30:B70; 10/14 h). Higher pigments contents (chlorophyll a, chlorophyll b, and carotenoid) were obtained when light regime LM9 (150 µmol m−2 s−1; R70:B30; 12/12 h) was applied. In general, cucumber seedlings grown under the LM9 regime showed a significant increase in growth as well as photosynthetic capacity. It seems that the content of photosynthetic pigments is the key factor responsible for the performance of cucumber seedlings grown under different lighting modes, compared to other traits studied. We recommend monitoring the content of chlorophyll a, b, and their ratio value when studying the light requirement of cucumber plants.

Modulations in Chlorophyll a Fluorescence Based on Intensity and Spectral Variations of Light

“…In another study, exposure of the leaves of lettuce plants to different R/FR LEDs altered the photochemistry of the plants. As compared to the control, which had an F V /F M value of 0.81, there occurred a reduction in the value of F V /F M , which was less than 0.8 after 11 days of treatments; the results indicate that in lettuce, R/FR exerts a stress on the plants, and this may be due to the absence of blue light [ 100 ]. The quantum yield of photosynthesis, ETR, and photochemical quenching were increased when seedlings of tomato were irradiated with a low R:FR value compared to the seedlings irradiated with a high R:FR value [ 3 ].…”

Enhancement of photosynthesis efficiency and yield of strawberry (Fragaria ananassa Duch.) plants via LED systems

“…Rocket plants responded to LM7 in a big way, not only in terms of shoot length, but also in terms of root length and total leaf area (Figure 3). Elmardy et al (2021) found similar findings in rocket salad plants with the combination of (220 μmol m −2 s −1 ; R70:G0:B30; 10 h/14 h) and in cucumber (Cucumis sativus L.) seedlings with the combination of (150 μmol m −2 s −1 ; R70:G0:B30; 12 h/12 h) exhibited the best results for plant height and number of leaves (Hamedalla et al, 2022). When plants were grown under low light intensity (100 μmol m −2 s −1 ) and a high blue ratio (30% red/70% blue), Liang et al (2021) found that a mix of red and blue lights was beneficial to plant height, total leaf area, and root length of passion fruit seedlings.…”

“…Light is one of the most important factors responsible for plant development and growth (Wassink and Stolwijk, 1956). Previous research has shown that changing light intensity, quality, and photoperiod may alter growth and govern developmental transitions (Meng et al, 2020;Elmardy et al, 2021;Liang et al, 2021;Hamedalla et al, 2022;Malekzadeh Shamsabad et al, 2022). Basic plant research using various light spectrums has shown that well-defined light wavelengths have a significant impact on plant physiology such as germination and stem development (Parks et al, 2001), biomass and flowering transition (Valverde et al, 2004), in the outcome of plant-pathogen interactions (Meng et al, 2020) and an increase in plant resilience under stress conditions (Malekzadeh Shamsabad et al, 2022).…”

“…The orthogonal array design, theory, and method is a modern time-and cost-effective research technique constructing an orthogonal array to classify regions where varieties may be successfully reduced (Ross, 1996), like the previously experiments have done in plants (Elmardy et al, 2021;Liang et al, 2021;Hamedalla et al, 2022) and animals (Shehata et al, 2020(Shehata et al, , 2022. Furthermore, the interaction effects between factors can be treated as autonomous factors and evaluated using the triangular table in relation to the associated orthogonal array preserving the advantages of the traditional fractional factor design (Cortés-Jacinto et al, 2005;Shehata et al, 2022).…”

Optimization of Extraction Conditions of Carotenoids from Dunaliella parva by Response Surface Methodology

“…An orthogonal design was used to obtain the optimal experimental conditions in iodine adsorption [ 49 ]. An orthogonal design was used to optimize light irradiance and the ratio of photoperiods and LEDs in order to increase the photosynthetic capacity and growth of cucumber seedlings by LED illumination [ 50 ].…”