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.

This experiment analyzed the effect of genetic determinants, the production technology, and the location on the nitrate and nitrites content in potato tubers directly after harvest. Nitrates and nitrites are anti-nutritional compounds, which limit or prevent the use of nutrients from consumed products and have a detrimental effect on the human body. The study was conducted on 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’, and ‘Tajfun’) at four locations in Poland under either an integrated (Młochów, Boguchwała) or organic (Radzików, Chwałowice) production system. The results showed that the production system, location, and year significantly affected the nitrate and nitrites content in potatoes. Potato tubers originating from organic farming exhibited a lower content of the tested compounds (NO₃⁻—124.1 mg kg⁻¹ FW; NO₂⁻—2.4 mg kg⁻¹ FW) than that in the tubers obtained from an integrated production system (NO₃⁻—203.7 mg kg⁻¹ FW, NO₂⁻—4.0 mg kg⁻¹ FW). Under conditions of moderate stress as usual in the case of organic farming, the production of nitrates and nitrites are significantly lower than in the integrated production system. In our research potatoes from an integrated production system were characterised by a nitrate content at the limit of the established standard, i.e., 200 mg kg⁻¹ FW. Tubers from the locality Chwałowice were characterised by the lowest nitrates and nitrites content, due to adequate environmental conditions, in addition to the best agricultural practice. The nitrates content depended to a greater extent on the environmental conditions than the potato on the genetic conditions. A higher content of nitrates and nitrites was found in the following potato clone 13-VIII-10 in Boguchwała from an integrated production system (NO₃⁻—269.2 mg kg⁻¹ F; NO₂⁻—6.0 mg kg⁻¹ FW), and in the ‘Tajfun’ cultivar (235.8; 5.8 mg kg⁻¹ FW, respectively). Such a relationship was not found in integrated production in Młochów, which indicates the influence of the environment.

The aim of this study was to determine the effect of cultivars on the concentration of antioxidant compounds: total carotenoid content (TC) and vitamin C (VC), and their correlation with the total antioxidant activity (TAA) in 65 potato cultivars (Solanum tuberosum) from 10 countries. The TC content revealed a highly significant effect of the year (Y), cultivar (C) and flesh colour (FC). The TC ranged from 101.5 µg 100 g⁻¹ DM (in cv. Kelly) to 715 µg 100 g⁻¹ DM (in cv. Mayan Gold). The TC values were weakly correlated with years and higher in yellow-fleshed potatoes than in white-fleshed potatoes (319.9 vs. 175.6 µg 100 g⁻¹ DM, respectively). The VC content ranged from 1.0 mg 100 g⁻¹ FM (in cv. Bzura) to 14.8 mg 100 g⁻¹ FM (in cv. Twinner). The content of VC were higher in yellow-fleshed (6.5 mg 100 g⁻¹ FM) than in white-fleshed potatoes (5.8 mg 100 g⁻¹ FM). The highest TAA were observed in cvs. Colleen, Basa, Triplo, Gatsby, Ditta, Twinner, Riviera, Michalina, Damaris, Belmonda, Ambo, Savinja, 12-LHI-6. For these cultivars, the FRAP values were 0.53 µmol TE 100 mg⁻¹ DM and DPPH 0.55 µmol TE 100 mg⁻¹ DM. The lowest TAA were observed in cvs.: Owacja, Mayan Gold, Kokra, Magnolia and Kelly. For them, the FRAP and DPPH values were slightly above 0.2 µmol TE 100 mg⁻¹ DM. It was shown that the concentration of TC in potato tubers has an impact on TAA.

Potatoes (Solanum tuberosum L.) are an important plant crop, whose yield may vary significantly depending on pedo-climatic conditions and genotype. Therefore, the analysis of the genotype × environment interaction (GEI) is mandatory for the setup of high-yielding and stable potato genotypes. This research evaluated the tuber yield (t ha⁻¹) and yield characteristic of nine potato cultivars over 3 years and 4 organic farms in Poland by additive main effects and multiplicative interactions (AMMIs) and genotype plus genotype environment interaction (GGE) biplot analyses. The results of these analyses indicated significant differentiation of tuber yield among genotypes in individual environments. It was found that the environment (E, where E = L (localization) × Y (year)), genotype (G) and GEI, but not replication, significantly affected tuber yield. The AMMI analysis showed that the environment factor explained the most considerable part of tuber yield variations (52.3%), while the GEI and G factors explained a much lower part of the variations. The AMMI and GGE analyses identified five cvs.: Twister (46.4 t ha⁻¹), Alouette (35.8 t ha⁻¹), Kokra (34.8 t ha⁻¹), Levante (33.1 t ha⁻¹), and Gardena (30.4 t ha⁻¹), as leading cultivars in the studied organic farms due to their high productivity coupled with yield stability. The statistical measure Kang (YS_i) showed that these cvs. can be considered as adaptable to a wide range of organic environments. In the case of morphological traits of tubers (tuber shape and depth of tuber eyes), the most important factor influencing both these traits was genotype (G). Influence of other factors, like localization (L), year (Y), and all interactions (double and triple), were much less significant or insignificant. In case of taste and non-darkening of tuber flesh, the main effects which significantly affected the values of these traits were genotype (G) and localization (L). We observed that cooking type can vary depending on the year (Y) and the localization (L).