Response of three bell pepper cultivars to different nutrient solutions in NFT hydroponic system

Optimizing hydroponic bell pepper (Capsicum annuum L.) production requires tailored nutrient solutions, as cultivar needs and climate conditions vary. This study therefore evaluated three globally-used nutrient solutions on three popular cultivars ('Nirvin', 'Aranko', and 'Taranto') under Iran specific climate, in a nutrient film technique (NFT) hydroponic system. The nutrient solutions tested were the standard Hoagland solution (control), the Netherlands nutrient solution, and the USDA-recommended solution. A factorial experiment based on a completely randomized design with three replications was conducted to assess growth, physiological traits, yield, and fruit quality parameters. Results showed that both cultivar type and nutrient solution significantly affected vegetative growth, reproductive traits, photosynthetic pigments, and fruit quality. 'Aranko' generally exhibited higher biomass accumulation (30.98% SDM) and leaf area (32.17%), especially when grown with the USDA solution, which also enhanced number of fruit (81.96%) and fruit mass (6.5%) compared to Hoagland solution. 'Nirvin' showed the highest leaf relative chlorophyll content (SPAD) and chlorophyll b content, particularly under the Hoagland solution. 'Taranto' demonstrated the highest photosynthetic efficiency across all nutrient solutions. The Netherlands and USDA solutions improved dry biomass and carotenoid content compared to the control. Photosynthetic parameters such as F_v/F_m and net photosynthesis were influenced by nutrient solution and cultivar interactions. Fruit quality traits, including firmness, vitamin C content, and color indices, were also enhanced by the USDA solution. Overall, the findings indicate that 'Aranko' showed the best results in yield, with superior biomass accumulation and fruit mass, particularly under the USDA solution.