Fertilization Management Improves the Yield and Capsaicinoid Content of Chili Peppers

Chili, one of the most cultivated plants in the world, from the genus Capsicum sp., has great importance both in human nutrition and in the pharmaceutical industry. This study provides detailed information on the impact of chili crop fertilization on the production and accumulation of capsaicin and dihydrocapsaicin. During the vegetation period, 235 kg∙ha−1 NPK (chemical—Ch), 270 kg∙ha−1 NPK (organic—O) and 250 kg∙ha−1 NPK (mixed—Ch + O) fertilizers were applied on six varieties of chili pepper (De Cayenne, Traian 2, Turkish, Sigaretta di Bergamo, Jovial and Chorbadjiiski); all versions were compared with the control (Ct). The determination of capsaicinoid compounds from chili pepper samples was done using high-performance liquid chromatography, HPLC-UV/VIS. The chili pepper plants reacted differently according to the fertilizers used, both in terms of the production and accumulation of capsaicinoids. The highest production was obtained for the case of mixed treatments in all cultivars, with the highest production being found for Sigaretta di Bergamo (40.61 t∙ha−1). The capsaicin and dihydrocapsaicin content was influenced by both the type of fertilizer used and the variety of chili pepper. The accumulation of capsaicinoids in the chili fruits was found to be dependent on cultivar and fertilization management; higher amounts of capsaicinoids were found to accumulate in the fruits of the Chorbadjiiski variety treated with chemicals (0.83 mg∙g−1 capsaicin and 0.53 mg∙g−1 dihydrocapsaicin) compared with the amounts found for untreated De Cayenne (0.52 mg∙g−1 capsaicin and 0.33 mg∙g−1 dihydrocapsaicin).