Effects of Nutrient and NaCl Salinity on Growth, Yield, Quality and Composition of Pepper Grown in Soilless Closed System

Abstract

The effects of nutrient or sodium chloride (NaCl) salinity on pepper grown in closed soilless culture systems were studied. A control (2 dS m⁻¹) and two saline nutrient solutions (4 dS m⁻¹) differing in the salt sources (fertilizers or NaCl) were studied. Shoot biomass production as well as total and marketable yield were more affected by NaCl than nutrient salinity. Fruit dry matter and total soluble solids increased in both salinity treatments compared to the control. Total phenol content rose slightly (10%) with NaCl salinity, while the concentration of carotenoids was enhanced by 40% with NaCl compared to the control and nutrient salinity. The results showed that the response of pepper to salinity is both osmotic and ion specific, but a more negative effect was recorded under NaCl stress. Moreover, the highest content of antioxidant compounds in NaCl treated fruits may indicate that NaCl caused more stressful conditions than nutrient salinity.

Keywords:

• Capsicum annuum L.
• salt stress
• blossom-end rot
• phenols
• carotenoids, antioxidant activity