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Morphological and Photosynthetic Parameters of Green and Red Kale Microgreens Cultivated under Different Light Spectra
Microgreens are plants eaten at a very early stage of development, having a very high nutritional value. Among a large group of species, those from the Brassicaceae family, including kale, are very popularly grown as microgreens. Typically, microgreens are grown under controlled conditions under light-emitting diodes (LEDs). However, the effect of light on the quality of grown microgreens varies. The present study aimed to determine the effect of artificial white light with varying proportions of red (R) and blue (B) light on the morphological and photosynthetic parameters of kale microgreens with green and red leaves. The R:B ratios were for white light (W) 0.63, for red-enhanced white light (W + R) 0.75, and for white and blue light (W + B) 0.38 at 230 µmol m−2 s−1 PPFD. The addition of both blue and red light had a positive effect on the content of active compounds in the plants, including flavonoids and carotenoids. Red light had a stronger effect on the seedling area and the dry mass and relative chlorophyll content of red-leaved kale microgreens. Blue light, in turn, had a stronger effect on green kale, including dry mass. The W + B light combination negatively affected the chlorophyll content of both cultivars although the leaves were significantly thicker compared to cultivation under W + R light. In general, the cultivar with red leaves had less sensitivity to the photosynthetic apparatus to the spectrum used. The changes in PSII were much smaller in red kale compared to green kale. Too much red light caused a deterioration in the PSII vitality index in green kale. Red and green kale require an individual spectrum with different proportions of blue and red light at different growth stages to achieve plants with a large leaf area and high nutritional value.
Sposób i urządzenie do generowania piany dla izolacji termicznej przegród, zwłaszcza w szklarniach, tunelach foliowych oraz innych budowlach
The Effect of the Cultivar and Process Parameters on Quality and Biologically Active Compounds Content in Impregnated Carrot Tissue
Vacuum impregnation (VI) allows soluble solids to be introduced into the porous matrix of a food material, modifying the composition of the tissue to facilitate further processing. The purpose of this research was to analyze the influence of pressure on the effectiveness of VI on a low porous material that is difficult to impregnate. Two cultivars of carrot (Baltimore F1 and Komarno) were subjected to VI at 5 and 30 kPa in a ternary solution of ascorbic acid (0.5%), citric acid (0.5%), and sucrose (8%) under isotonic conditions. The products were analyzed in terms of ascorbic acid content, degree of impregnation, and changes in structure, texture, color, antioxidant activity, phenolic content, carotenoids, and structure-forming compounds. Increases in vitamin C content (after VI) depended on the process conditions and ranged from 900% to 1300% in relation to the raw material. It was also observed that the extended impregnation time at a pressure of 5 kPa produced slices that were also impregnated in parenchyma area. The increased levels of polyphenolic compounds found in the saturated product may suggest that de novo synthesis under the influence of physiological stress had occurred.
Concentration of heavy metals in urban allotment soils and their uptake by selected vegetable crop species - a case study from Gorzów Wielkopolski, Poland
Does Elemental Sulfur Act as an Effective Measure to Control the Seasonal Growth Dynamics of Potato Tubers (Solanum tuberosum L.)?
The in-season dynamics of potato tuber biomass (TTB) growth requires effective nitrogen (N) control. This hypothesis was tested in 2006 and 2007. The two-factorial experiment with two rates of N (60, 120 kg ha−1) and sulfur (S; 0, 50 kg ha−1) was carried out in the split-plot design. The third factor was the sampling of plants at 10-day intervals. The collected plant material was divided into leaves, stems, stolons + roots, and tubers. The seasonal trend of TTB was linear, while the biomass of leaves, stems, and stolons + roots was consistent with polynomial regression models. TTB was controlled by (i) the date of potato growth after emergence, when the TTB exceeded the leaf biomass (DAEcrit); (ii) the stem growth rate; and iii) the share of stems in the total potato biomass. TTB growth was reduced when DAEcrit preceded the DAEop for leaf biomass, determining its maximum. This phenomenon appeared in 2007 on plots fertilized only with N. The absolute growth rate of the stem biomass, exceeding ¼ of that of the tuber biomass in the descending phase, resulted in an increased and prolonged share of stems in the total potato biomass, which ultimately led to a decrease in tuber yield. The use of sulfur to balance the N, applied effectively, controlled the growth rate of potato organs competing with tubers.
Effect of ultrasound on mass transfer during vacuum impregnation and selected quality parameters of products: A case study of carrots
System wietrzenia budowli z dachami izolowanymi termicznie pianą, zwłaszcza w szklarniach i tunelach foliowych oraz innych budowlach
The effect of spent mushroom substrate enriched with selenium and zinc on the yield and photosynthetic parameters of lettuce (Lactuca sativa L.)
The aim of the study was to investigate the influence of Agaricus bisporus spent mushroom substrate (A-SMS) enriched with selenium (Se) and zinc (Zn) on the yield and photosynthetic parameters of lettuce (Lactuca sativa L. var. capitata) of the ‘Skindel’ cultivar. The growing medium for the cultivation of lettuce consisted of A-SMS (10%) and commercial peat (90%). It was further enriched with Se and Zn concentrated at five levels, i.e. 0.1, 0.2, 0.4, 0.6, and 0.8 mmol·L–1 to obtain six growing medias. Se was added to the growing medium in the form of sodium selenite and sodium selenate at a 1:1 ratio, whereas Zn was added in the form of zinc nitrate hexahydrate. Lettuce was grown under controlled conditions in growth chambers. The experiment was conducted in a randomised complete block design in three replicates. The results indicated that the A-SMS added to the growing medium increased both the yield of lettuce and its biological value by increasing the content of Se and Zn. Consumable percent recommended daily allowance and safe hazard quotient for lettuce biofortified with Se and Zn were achieved. The experiment also showed that the addition of Se + Zn did not negatively affect photosynthesis and chlorophyll fluorescence parameters, which proved that these elements did not have toxic effect on lettuce in agronomic perspective.