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Light intensity and wind are critical environmental factors of abiotic stress on plants, triggering a considerable number of morphological and physiological responses. This study tested the hypothesis that different light and wind conditions (full sunlight ± wind, shade ± wind) would affect the leaf content of photosynthetic pigments and anthocyanins, as well as the plant height, the fresh and dry weight of the aboveground part, and Water-Use Efficiency on Ocimum basilicum plants. About 16 days after the application of the different conditions, all leaf pigments of the shaded plants exhibited increased contents compared to the lightened ones. Subsequently, this response was enhanced until the 39th day, which was the final day of the experiment. Furthermore, shaded plants grew taller, although their fresh and dry weight and Water-Use Efficiency were lower than that of the corresponding lightened ones. On the other hand, wind did not have any effect on pigment content. Concerning the plant growth indexes, reduced values were observed on the wind-treated plants. The above results demonstrate a considerable effect of light intensity while the applied wind seems to be mild enough to induce important plant responses, partially confirming the hypothesis studied. [ABSTRACT FROM AUTHOR]

Plant factories with artificial lighting (PFALs) are indoor crop production systems aiming at the growth of high-value products in terms of yield and quality, while maximizing resource use efficiency. The emergence of PFALs opened a new world for crop production and offered an option to tackle problems related to climate change, land availability, and urban/peri-urban farming. This was made possible upon major technological advancements and extensive research in the field of controlled environment agriculture, which paved the way for the establishment of such cost-efficient and climate-unaffected modules of vegetable and other crops' production. In the present review, we have examined the recent research achievements regarding the micro-environmental factors, the principal components, as well as the automated systems used for plant production in PFALs. Ultimately, we provide the reader with a number of future perspectives that can be considered for indoors cultivation in the following years. [ABSTRACT FROM AUTHOR]

Wild rocket is a leafy vegetable with economic interest as a consequence of baby leaf ready-to-eat salads. The climate crisis is expected to influence wild rocket production, but these effects could be confronted with cultivation in greenhouses and plant factories with artificial lighting (PFALs). Climate responses are related to growing seasons. Our objective was to test the impact of two growing seasons, winter and summer, on the growth and physiology of wild rocket baby leaves in different controlled environment systems (greenhouse and PFAL). The growth cycle was reduced by 27% in the PFAL compared to the greenhouse during winter. Summer yield was greater in the greenhouse, but leaf number and area were greater in the PFAL. The lowest water use efficiency was recorded in the greenhouse during summer. Energy use efficiency was lower in PFAL compared to the greenhouse. Land use efficiency was not affected by the growing system, but in PFALs it is able to increase it by growing in vertical layers. Relative chlorophyll content and total soluble solids were enhanced in the greenhouse. The photosynthetic efficiency evaluation showed considerable stress in summer-grown plants in the greenhouse, as shown by PIABS and φP0. In general, the production was similar in the PFAL regardless of seasons. [ABSTRACT FROM AUTHOR]

Oaks (Quercus spp.) represent the most important broadleaf genus with respect to forest-shaping tree species in the Mediterranean. Considering future climate scenarios (increased drought conditions), the identification of drought tolerant oak species is of great importance for future forest management in this region. The objective of the study was the comparison of physiological status of three economically and ecologically valuable oak species (Quercus ilex, Quercus frainetto and Quercus pubescens) co-existing in natural coppice stands in NE Greece, in response to seasonal drought stress. Measurements were conducted between June and September 2016, every 15–20 days until leaf falling. The parameters studied were predawn leaf water potential and fast chlorophyll fluorescence induction curves (OJIP test), chlorophyll content, and relative water content. Meteorological data from the area were also collected. Photosynthetic parameters such as performance indices (PIabs and PItot) reacted to summer drought conditions, with Q. frainetto showing the lowest values. The discrepancy between species increased with duration of drought period. Q. frainetto revealed the lowest predawn water potential values. The results indicate that Q. frainetto is less suitable for future forestry applications in the studied climate/elevation zone than Q. pubescens and Q. ilex. [ABSTRACT FROM AUTHOR]

The objective of the present study was to investigate the impact of light-emitting diodes (LEDs) on the morphological and developmental characteristics of wild cherry (Prunus avium) and common dogwood (Cornus sanguinea). The LEDs used were L20AP67 (moderate blue, red and far-red, high green), AP673L (moderate blue, high red), G2 (low blue, high red and far-red), AP67 (moderate blue, red and far-red), and NS1 (high blue and green, low red, high red:far-red, 1% ultraviolet). Fluorescent light [FL (high blue and green, low red)] tubes served as the control treatment. The growth rate and subsequently the shoot height of Cornus sanguinea were greater under FL. Root length of Prunus avium was longer under NS1. Prunus avium produced more biomass under NS1 and AP67, while Cornus sanguinea was favored under G2 and AP67. Greater root:shoot ratio was found under NS1 for Prunus avium and under NS1, AP67, G2, and AP673L for Cornus sanguinea. Root growth capacity (RGC) was also assessed in order to evaluate the transplanting response. RGC of Prunus avium and Cornus sanguinea was favored after precultivation under G2 and AP67, and under NS1 and AP67, respectively. Our study demonstrated that LEDs were more efficient in promoting a number of morphological characteristics than conventional FL in Prunus avium and Cornus sanguinea. [ABSTRACT FROM AUTHOR]

In many countries of Europe and Eastern Asia, watermelon production is mainly based on the use of grafted seedlings. Upon grafting, seedlings undergo a period of healing where artificial lighting is provided by light-emitting diodes in controlled chambers in order to accelerate and improve the healing process. The objective of our study was to test the effect of light quality on the final product (i.e., seedlings ready for transplanting) in the nursery, as well as to evaluate the possible implications on fruit quality after field cultivation. Narrow-band blue (B) and red (R) wavelengths, 64–36% R-B (36B), 76–24% R-B (24B), 88–12% R-B (12B), and 83–12% R-B plus 5% far-red (12B+FR) wavelengths were tested. 12B+FR enhanced the root dry weight, root architecture, and maximum photosynthetic rate, while RB combinations generally showed better root system development with increased blue portion. R light induced inferior root dry weight and quality indices (root/shoot and shoot–dry–weight/length ratios), lower gas exchange parameters, and chlorophyll content, but high shoot length and leaf area. B light led to inferior root architecture, lower stem diameter, leaf area, and maximum photosynthetic rate. Both R and B wavelengths showed decreased concentration of macronutrients and trace elements. After field cultivation, fruit quality (i.e., morphology and color), and valuable nutritive characteristics (i.e., phenolics, carotenoids, lycopene, antioxidants) maintained high quality irrespective of light treatments. Overall, 12B+FR performed well in almost all qualitative parameters including the morphology, the root development, and photosynthesis, while also maintaining high fruit quality. [ABSTRACT FROM AUTHOR]