The presented paper deals with monitoring of the ways of selenium (Se) content increase by foliar biofortification with inorganic Se in two varieties of garden pea Pisum sativum L. (Premium, Ambassador) in the conditions of south Slovakia in 2014-2015. The results of experiments show that treatment of plants with two doses of Se concentration (50 g and 100 g Se ha -1 in the form of a sodium selenate anhydrous solution) at the flowering stage significantly increased the total Se content in the seeds of both varieties. Following the results by the consumption of 25 g of dried seeds of peas or 100 g of fresh pea seeds after the biofortification with 100 g Se ha -1 a recommended daily dose of Se in humans may be covered. The significantly positive influence of Se application on the total polyphenols content (TPC) has been confirmed in the both varieties after application of dosage in 100 g Se ha -1 (52% and 33%). A significant increase in the average value of total antioxidant capacity (TAC by DPPH method) in garden pea var. Ambassador was observed after the application of both doses of Se, in case of Premium variety only after application with a 100 g Se ha -1 . Significantly increasing level of TAC by PCL (photochemiluminescence) method was found out only in case of var. Premium.

The species Pleurotus ostreatus is a commercially, gastronomically, and biotechnologically important fungus. Its strain variability has been little researched. The study provides an evaluation of 59 oyster mushroom production strains in terms of the ability to accumulate selected metals in the cap and stipe. The fruiting bodies were grown under identical model conditions on straw substrate. Metal concentrations (ET-AAS) in dry fruiting bodies ranged in values 1.7–22.4 mg kg−1 for Al, 2.6–9.7 mg kg−1 Ba, 199–4560 mg kg−1 Ca, 1.7–12.0 mg kg−1 Cu, 12–120 mg kg−1 Fe, 16,000–49,500 mg kg−1 K, 876–2400 mg kg−1 Mg, 0.39–11.0 mg kg−1 Mn, 46–920 mg kg−1 Na and 11–920 mg kg−1 for Zn. More Cu, Fe, K, Mg, Mn, Zn accumulated in the cap, while in the stipe Ba was amassed. No significant difference was found between Al, Ca and Na between the accumulation in the cap and the stipe. Furthermore, the dependence of metal uptake from the substrate depending on the fortification of the substrate was confirmed. Statistically significant (p < 0.05) synergistic relationships were shown in pairs Al and Ba, Al and Fe, Ba and Na, Ba and Ca, Ca and Na, Cu and Fe, Fe and Mn, Fe and Zn, K and Mg, K and Mn, K and Zn, Mg and Mn, Mg and Na, Mg and Zn and Mn and Zn in the substrate without the addition of sodium selenate to the substrate. Altered relationships were observed after the application of sodium selenate to the substrate, synergism of Se and Ni, Se and Co and Se and Hg, Cu and Mn, Cu and Fe, Zn and Co, Zn and Ni, Zn and Hg, Mn and Fe, Mn and Cr, Co and Ni, Co and Hg, Ni and Hg, Pb and Cd. The findings of the study may help in the selection of production strains with hypercumulative properties for a particular metal and subsequent use in the addition of fortified fruiting bodies (e.g., with Zn). Based on the study the strains less sensitive to the accumulation of hazardous metals is possible to select for large-scale production, which is important from the perspective of food safety.

The study monitored the effect of differentiated mineral nutrition of microgreens species by solution of sodium selenate (2 mg Se/L) on the content of Se, chlorophylls, and other minerals. Chlorophylls were measured spectrophotometrically, Se by electrothermal atomic absorption method (ETAAS) with Zeeman-effect background and elements' concentration was performed by a dual Inductively coupled plasma atomic emission spectroscopy (ICP-OES) iCAP7600 instrument. The content of selenium in fresh weight moved on average from 0.013 to 12.556 μg/g. Selenisation increased the content of Se in all tested species significantly (p < 0.05) without impacting yield. The content of chlorophyll a moved from 249.9 mg/kg (Mizuna) to 604.4 mg/kg (Arugula) with significant differences between the species, without significance (p ≤ 0.05) between tested variants. The influence of selenisation on other minerals significantly differed (p < 0.05) due to the genetic variability. A significant (p ≤ 0.05) increase in Ca was observed in green basil (10.7%) and cress (20.9%); of Fe in green basil (1.6%) and cress (40.9%); of K in arugula (1.6%), green basil (3.9%) and cress (2.8%); of Zn in arugula (2.6%), green basil (8.6%), cress (2.7%) and radish (5.9%); and of Ba in green basil (5.6%) and cress (23.9%).

The sweet potato (Ipomoea batatas L.) belongs to very important crops from aspect of its world production. It is grown in large areas in Asia, on the contrary, sweet potato production in Europe presents minimal part of its total world rate. The sweet potato is less-known crop, grown only on small area in home gardens in Slovak Republic. Tubers of sweet potato are characterized by anti-diabetic, anti-oxidant and anti-proliferative properties due to the presence of valuable healthpromoting components, such as carotenoids or vitamin C. The main objective of study was testing of sweet potato growing in conditions of southern Slovak Republic with focus on quantity and quality of its yield. The field trial was realised on land of the Slovak University of Agriculture in Nitra in 2015. Within trial, effect of cultivar and mulching on the selected quantitative (average tuber weight; yield per plant; yield in t.ha -1 ) and qualitative (total carotenoids; vitamin C) parameters were tested. One certified cultivar of sweet potato 'Beauregard' was used as a comparative cultivar. Other two cultivars were marked according to the market place at which were purchased and sequentially used for seedling preparation. Tubers of first un-known cultivar were purchased in the Serbian market (marked as 'Serbian'). Tubers of next sweet potato cultivar were purchased on the market in Zagreb (marked as 'Zagrebian'). Outplating of sweet potato seedlings were realised on the 19th May 2015. The sweet potato was grown by hillock system. Each cultivar was planted in two variants (rows): nonmulching (bare soil) and mulching by black non-woven textile. All variants were divided to three replications with 6 plants. Difference between rows was 1.20 m and seedlings were planted in distance of 0.30 m in row. The harvested tubers were classified in two size classes: >150 g (marketable yield) and <150 g (non-marketable yield). Total carotenoid content was determined spectrophotometrically. The vitamin C content was measured chromatographically (HPLC). The highest values of average tuber weight, yield per plant and total yield (t.ha -1 ) were found in cultivar 'Serbian'. Statistical analysis showed statistically significant difference in all yield quantitative parameters of cultivar 'Serbian' against cultivars 'Beauregard' and 'Zagrebian'. The highest content of total carotenoids was determined in cultivar 'Serbian' (99.52 mg.kg -1 fresh weight) with orange-creme flesh color, followed by cultivar 'Beauregard' (94.78 mg.kg -1 ) with orange flesh color and cultivar 'Zagrebian' (28.79 mg.kg -1 ) with yellow-creme flesh color. Differences among all cultivars were showed as statistically significant. The highest vitamin C content was detected in tubers of cultivar 'Serbian' (155.70 mg.kg -1 ), followed by cultivar 'Beauregard' (154.37 mg.kg -1 ) and cultivar 'Zagrebian' (146.33 mg.kg -1 ). Statistical analysis confirmed differences among cultivars as statistically non-significant. The mulching of sweet potato plants had statistically significant impact to all ...

The sweet potato (Ipomoea batatas L.) is relatively known vegetable species, but it is grown only on small area in the Middle European region. Its cultivars are characterized by different colour of tuber flesh which can be white, beige, yellow, orange and purple. The aim of this study was to determine and compare selected qualitative parameters of tubers (total carotenoids, vitamin C and total soluble solids) among orange, white and purple sweet potato cultivars. The field experiments were established at Slovak University of Agriculture in Nitra in 2016 and 2017. Sweet potatoes were grown by hillock system with using of black non-woven textile for soil mulching. The tuber harvest was realised on the 6th October 2016 and 13rd September 2017. The highest content of total carotenoids was found in orange sweet potato cultivars (78.47 - 122.89 mg.kg-1 fresh weight) and its values were multiple-fold higher in comparison with purple (4.22 mg.kg-1 f. w.) and white (10.71 mg.kg-1 f. w.) cultivars. Orange cultivars were also richer source of vitamin C (246.31 - 325.99 mg.kg-1 f. w.) compared to white (179.66 mg.kg-1 f. w.) and purple (187.75 mg.kg-1 f. w.) cultivars of sweet potatoes. The total soluble solids, expressing mainly sugar content, was higher in purple (10.13 °BRIX) cultivar of sweet potatoes, followed by cultivars with orange (8.52 - 9.72 °BRIX) and white (5.57 °BRIX) tuber flesh. Obtained results showed the significant effect of cultivar, characterized by different tuber flesh colour, on the composition and contribution of sweet potatoes for human health.

Food safety is a very frequent topic. The article deals with the problems of fortification of the most grown mushroom in Slovakia, and the 3rd most grown mushroom in the world, Pleurotus ostreatus. Due to the high environmental pollution of soils and air, there is a risk of the production of dangerous fruiting bodies with high heavy metals content. It is known that these substances can promote serious health effects on human body, such as bone weakness or kidney damages (cadmium) and negative process of cognitive developing (lead). The experiment was focused on biofortification with selenium to reduce the accumulation of selected heavy metals (lead, cadmium) in oyster mushroom, grown with intensive cultivation under artificial conditions. This work confirms that the application of sodium selenate to the growing substrate with straw as the main component can reduce the accumulation of cadmium (by 22.45%) and lead (by 64.81%). Research by various authors reported the ability of the oyster mushroom to embed selenium from the substrate into the fruiting bodies. Based on the results of the experiments, we propose to fortify the growing substrate for the production of oyster mushroom by selenium. This way we produce a food with a high antioxidant potential.

Oyster mushroom (Pleurotus ostreatus) is still one of the most cultivated edible and medicinal mushrooms. Despite its frequent cultivation around the world, there is currently just a little information available on the variability of strains in terms of the content of β-glucans in them. This work presents an extensive study of 60 strains in terms of the content of α-glucans and β-glucans in their caps and stipes. The authenticity of the production strains based on an analysis of the variability of their genome by CDDP (Conserved DNA-derived polymorphism) markers was confirmed, whereas identical CDDP profiles were identified between samples 45, 89, 95, and 96. Genetic variability of the analyzed production strains showed a high polymorphism and effective discriminative power of the used marking technique. Medium positive correlations were found among the CDDP profiles and β-glucan content in the group of strains that generated the same CDDP profiles, and low negative correlation was found among these profiles in the group of low β-glucan content strains. For the determination of glucans content, Mushroom and Yeast analytical enzymatic kit (Megazyme, Bray, Co. Wicklow, Ireland) were used. The results clearly showed that the stipe contains on average 33% more β-glucans than the cap. The minimum detected β-glucan content in the stipe was in strain no. 72, specifically 22%, and the maximum in strain no. 43, specifically 56%, which after the conversion represents a difference of 155%. From the point of view of β-glucan content, the stated strain no. 43 appears to be very suitable for the commercial production of β-glucans under certain conditions.

Licensed under a Creative Commons Attribution 4.0 International License The use of organic amendments for improving soil properties including soil structure is crucial for sustainable soil management. In this study, two organic materials (1. compost, and 2. farmyard manure) both at a rate of 44 t ha -1 as well as their combination were applied to a Hortic Calcaric Fluvisol (Slovakia) to evaluate the soil physical properties to test the potential of these amendments for soil amelioration under gardening conditions. The results showed that the addition of organic amendments did not have any significant effects on bulk density, total porosity, soil moisture and aeration, but their application influenced the total contents of dry-sieved aggregates as well as water-stable aggregates. The highest content of dry-sieved macro-aggregates was in compost > farmyard manure + compost > farmyard manure > control (unfertilized). The stability of aggregates was higher in compost and farmyard manure + compost treatments than in farmyard manure compared to control. Also, better soil structure stability evaluated by vulnerability coefficient was in farmyard manure + compost and compost than in farmyard manure. The highest contents of soil organic carbon and humic substances were found in the farmyard manure + compost treatment and then compost > farmyard manure > control. In compost, farmyard manure and farmyard manure + compost treatments, cabbage yield increased by 52, 22 and 72%, respectively compared to control treatment. Cabbage yields linear also increased as a result of increasing of soil organic carbon and humic substances.