AbstractIn this study, three cultivars and seven tetraploid potato clones were evaluated for two years in two cultivation systems (CS): without chemical protection against late blight development (NP) and with chemical protection (P). The objective of this study was to quantify the effect of chemical protection on the level of total carotenoids (TC) and individual carotenoids in potato tubers. The presented study showed that the content of TC in potato tubers is significantly affected by the CS and genotype. TC were higher in the system NP (mean 329.6 µg/100 g fresh weight [FW]) than in the system P (mean 206.2 µg/100 g FW). Although the development of late blight was observed only in the year 2019, a higher content of TC was observed in the system NP in both years. This dependence clearly show that CS without chemical protection favor carotenoids accumulation in potatotubers. In the case of lutein, the year had a significant impact on the concentration. The concentration of lutein in 2018 for the majority genotypes was higher (mean 72.1 µg/100 g FW), than in year 2019 (mean 37.3 µg/100 g FW), when late blight development wasobserved. The sharp decrease in lutein content in 2019 was probably caused by the development of late blight. A significant decrease of lutein content in potato tubers was observed in 2019 for all genotypes in system P and for five genotypes in system NP. It can be assumed that resistance mechanisms that occur during infection may have disturbed the accumulation of lutein in potato tubers.