ELECTRICAL CONDUCTIVITY OF NUTRIENT SOLUTION AND THEIR EFFECT ON BIOACTIVE COMPOUNDS AND YIELD OF BELL PEPPER (Capsicum annuum L.)

Abstract

Background. The electrical conductivity (EC) of a nutrient solution (NS) in hydroponic or soilless systems influences the yield and quality of the fruits. Objective. The aim of this research was to determine the quality and fruit yield of bell pepper in response to the electrical conductivity of the nutrient solution. Methodology. A completely randomized experimental design with 15 replications was used. The treatments consisted of four nutrient solutions with different electrical conductivity (1.5, 2.0, 2.5 and 3.0 dS m-1) based on the Steiner nutrient solution. Yield, firmness, and bioactive compounds (phenolic compounds, vitamin C, lycopene, β-carotene, and the antioxidant activity) were quantified in fruits. Results. The results showed that an electrical conductivity of 2.0 dS m-1 or higher increased the bioactive compounds but decreased the yield and firmness of the fruits. Implications. The correct selection of the EC in the NS is a preponderant factor to get functional foods, with high yields and to avoid unnecessary costs in fertilization Conclusion. The high EC in the NS reduced the yield and the firmness of the fruits. From an EC of 2.0 dS m-1 in the NS, the content of vitamin C, total phenols, lycopene, total capsaicinoids, β-carotene and the antioxidant activity of pepper fruits increased.