Aquaponic growth of basil (Ocimum basilicum) with Mozambique tilapia (Oreochromis mossambicus) in standard substrate

Aquaponics, the integrated production of fish and hydroponic crops in a recirculating system, is an intensive cultivation method in which metabolic fish wastes fertilize plants. Basil (Ocimum basilicum L.) is one of the most sought-after herbs in the market used in medicine. Although basil is highly sought after for its properties, there is limited information about its behaviour in aquaponics. Therefore, in 2024 (from July to August), this study was undertaken at the University of Limpopo for 50 days to investigate the production of basil (Ocimum basilicum L.) under a recirculating aquaponic system. This study aimed to assess the growth and development of this plant under aquaponic conditions. Three single and equal aquaponic systems were used, each consisting of a pond, a clarifier, three biofilters, and a hydroponic bed. These elements are interconnected with PVC pipes. Each pond was injected with air through aerator stones. Randomly, ten basils (O. basilicum), which were obtained from a commercial nursery (about 90 days old), were placed in each aquaponic system. A total of 30 tilapia specimens (O. mossambicus), ten fish per pound, were used. The results indicate a positive growth rate for basil with a strong coefficient of determination (R²= 0.95) during the experiment. On the other hand, the PCA results (. F¹= 72.99%, and F²= 23.66%) showed two groups of the growing stage, which refers to different plant growth rates and temperatures. In conclusion, the basil exhibited good productivity, indicating efficient nutrient assimilation in this system. Therefore, the evaluated basil is well-suited for these conditions and can be utilized as part of the biological filters in aquaponic systems with tilapia production.