Effect of selected factors on total carotenoid content in potato tubers (Solanum tuberosum L.)

In the years 2004 and 2005 precise field trials were performed with the aim to evaluate the effect of variety, year of cultivation, N, P, K and Mg fertilization, and the cover with white polypropylene fibre Paegas-Agro UV 17 on the total carotenoid content (TC) in potato tubers. TC was determined by absorption UV-VIS spectrophotometry and the results were statistically evaluated (ANOVA and MANOVA variance analyses, Scheffe's test). Significant differences in the ability of varieties to synthesize carotenoids were found (Karin, Agria and Marabel with high TC x Impala and Saturna with low TC). TC was also significantly affected by the year of cultivation (5.8 mg/kg fw in 2004, 20.9 mg/kg fw in 2005), whereas fertilization with N, P, K and Mg had no effect. The effect of white polypropylene fibre tested in two early potato varieties (Adora and Impala) was not significant either. Contrariwise, statistically significant effects on TC were also reported in the case of potato tubers maturity.