The concentrations of the bioactive compounds in potato tubers are determined by both genetic potential and environmental factors. The purpose of the experiment was to determine the influence of organic and integrated production on the expression of the genetic potential with respect to the antioxidant properties of potato tubers and to evaluate its stability under different environmental conditions. This phenotyping was performed on seven new breeding lines (tetraploid clones) and three modern cultivars: Jelly, Satina and Tajfun. The results indicated that production system and location significantly influenced the antioxidant capacity measured by FRAP method. Organic farming and the location Chwałowice were characterized by higher values. Furthermore, anitioxidative capacity measured by FRAP method was correlated with chlorogenic acid content (r = 0.590**) and glutathione fractions, especially with the reduced form (GSH, r = 0.692**). Multidimensional comparative analysis (MCA) proved a better development of antioxidant properties of potato tubers in the organic cultivation system when compared with the integrated. Especially favorable were growing conditions at Boguchwała (organic) and worst at Młochów (integrated). From all investigated varieties, the best antioxidant properties were found in ‘Satina’ and ‘Jelly’. Clones TG-97-403 and 13-VIII-45 developed the weakest health promoting traits.

The carrot (Daucus carota L.) is a staple vegetable in human nutrition in Europe. In recent years, the use of biostimulants in vegetable crops has become a way to affect the quantity and quality of yields. The aim of this study was to assess the effect of the type and methods of biostimulant (natural seaweed extract Kelpak and synthetic Asahi) application on the nitrates and nitrites content in carrot roots after harvest and storage. The study was based on a strict field experiment with carrot cv. ′Karotan′, conducted in Poland (53°13′N; 17°51′E) in three successive growing seasons and after six months of storage (RH 95%, and air temperature +1 °C). The biostimulants were applied during the growing season in a foliar form. The content of NO₃ˉ and NO₂ˉ in carrot after harvest depended on the dose and the date of biostimulant application. The single application of biostimulant Kelpak as well as two times of Asahi had no effect on the nitrate and nitrite content, while the application of Kelpak in a total dose of 6 or 7 dm³ ha⁻¹ increased them. The maximum intake of nitrates and nitrites following the harvest and storage was, respectively, 7.1, 2.3% and 6.7, 2.1% of the ADI.

Because of its high nutritional value, culinary suitability, broad processing possibilities and year-round availability, carrot is used primarily for direct consumption and secondly as raw material in food and industry processing. Raw carrot is an important source of human nutritional diet, being that of a total 52 kg of vegetables consumed on a yearly basis per person in Poland, carrot itself contributes 8.5 kg (Central Statistical Office, 2016). Content of carotenoids, sugars, vitamins, minerals and fibre are important in determining carrot root nutritional value (^{Kiraci & Padem, 2016}).

Barley (Hordeum vulgare) grain stands out among other cereals due to its high nutritional value. It results mainly from the high content of fiber and antioxidants, such as phenolic compounds. Barley grains can also be an important source of unsaturated fatty acids and carotenoids that are beneficial to health. This study assessed the effect of the foliar application of an amino-acid biostimulant on the content of phenolic compounds, carotenoids, and the composition of fatty acids in the grain of alternative, black-grain barley genotypes, and the commonly used ‘Soldo’ cultivar, grown in conventional and organic farming systems. The dark-pigmented grains contained significantly more phenolic acids and flavonoids than the yellow seed of the traditional cultivar and were characterized by a significantly higher proportion of unsaturated fatty acids. The application of the biostimulant significantly increased the concentration of phenolic compounds in grains, especially of alternative genotypes.

The aim of the study was to assess the content of total organic carbon (TOC), macronutrients (P, K, and Mg), and glomalin (easily extractable glomalin-related soil protein (EEGRSP)) in soil, micronutrients (Zn and Cu) in soil and wheat, and the number of insects on plots in an organic (OF) and a conventional farming (CF) system, all against the background of alkaline phosphatase (AlP) and acid phosphatase (AcP) activity. The experimental design included two spring wheat species, Triticum sphaerococcum Percival and Triticum persicum Vavilov, and three sowing densities (grains m⁻²): 400, 500, 600. Statistical analysis (ANOVA, η² effect size) showed significant variation in parameters under the influence of experimental factors. In the duration of the field experiment, TOC content in soil had decreased by 61% compared to the content before starting the experiment. The contents of P, K, and Mg and activity of AlP and AcP were higher in soil under T. sphaerococcum. With a sowing density of 600 grains m⁻² under OF and CF, the significantly lowest macronutrient content and the highest AlP and AcP activity were found. The parameters tested (TOC, EEGRSP, P, K, Mg, TZn, TCu, AZn, CU in plant, AlP, AcP) were higher under the CF than under the OF system. The experimental factors (spring wheat species and number of germinating grains) were demonstrated to influence the content of the forms of both microelements in soil and plants. In CF, more content in the amount of Zn and Cu was found than in OF. But the content they had did not exceed the standards set for arable soils. Both wheat species had a significant impact on the concentration of glomalin in the soil from the fields cultivated in the OF system. In CF, a significant difference was caused by sowing density and by interaction between wheat species and sowing density. Insects preferred plants grown in the OF system compared to CF. Regardless of cultivation system, the number of insects was greater on the plots of T. sphaerococcum than on plots of T. persicum. There were more insects at higher sowing densities in plants grown in the OF system only.

Photosynthetic properties and tuber yield were compared in seven tetraploid potato (Solanum tuberosum L.) clones (‘13-VIII-10’, ‘13-VIII-27’, ‘13-VIII-45’, ‘13-VIII-49’, ‘13-VIII-50’, ‘13-VIII-60’, ‘TG-97-403’) and three cultivars (‘Jelly’, ‘Satina’, ‘Tajfun’) at four localities in Poland under either integrated (Młochów, Boguchwała) or organic (Radzików, Chwałowice) fertilisation conditions applying the ‘OJIP’ analysis of chlorophyll fluorescence kinetics. The yield-relevant parameters of leaf pigment content and chlorophyll fluorescence were used to rank the tested clones and cultivars applying multidimensional comparative analysis. The results indicate that the clones 13-VIII-10 and 13-VIII-45 cannot be recommended for cultivation, while cv. Taifun performed the best. The assessment of the efficiency of the light reactions of photosynthesis produced a different ranking, indicating that the efficiency is not related to yield, but characterises the balance between light harvesting and dark reactions of photosynthesis. In this respect, the light reactions of photosynthesis were least balanced in clone 13-VIII-49 and cv. Jelly while those of cv. Taifun and clone 13-VIII-60 were the best. The effect of the production system was of minor significance for tuber yield, but local factors dominated. Only in the case of chlorophyll (Chl) and carotenoid (Car) contents of leaves did an effect of the production system became evident, favouring integrated over organic cultivation. By contrast, most of the chlorophyll fluorescence parameters were controlled by soil nitrogen content, including maximum quantum yield for primary photochemistry (φ_P0) and the absolute and total performance indices (PI_Abs, PI_Total). Within a production system precipitation affected the ratio Car/total Chl content.