Effects of urea fertilizer and nettle extract on the biochemical and morphological characteristics of ornamental peppers (Capsicum frutescens L.) under deficit irrigation conditions

Abstract

The aim of this study was to determine the effects of nettle extract, urea fertilizer and deficit irrigation on the biochemical and morphological characteristics of ornamental peppers. The study consisted of two irrigation (I) treatments (100% irrigation (I100) and 50% irrigation (I50)) and four fertilizer treatment groups (urea fertilizer: U; nettle extract applied through soil: SN; foliar nettle extract application: LS). The highest fruit weight was obtained in the U treatment, whereas the highest plant height and plant diameter were obtained in the LS and SN treatments. The fruit weight in SN was 18% lower than that in U. Capsaicin concentrations were highest in the LS treatment (1132.8 mg kg⁻¹) and lowest in the U treatment (286.4 mg kg⁻¹). The ascorbic acid concentration was highest in the I treatment (84.9 mg 100 g⁻¹) and lowest in the LS treatment (49.9 mg 100 g⁻¹). The total phenolic compound (TPC) content was highest in the U treatment (399.7 mg GAE 100 g⁻¹, GAE: gallic acid equivalents; the total phenolic content was expressed as gallic acid equivalents in mg·100 g⁻¹ wet weight) and lowest in the LS treatment (304.97 mg GAE 100 g⁻¹). As a result, nettle extract alone is insufficient to achieve high yields, but when it is applied together with urea fertilizer, it increases yield.