Current Status of the Propagation of Basil in Aquaponic Systems: A Literature Review

Basil (Ocimum sp.) is a commercially important herb that has been coupled with several aquatic organisms in aquaponic systems. The goal of this literature review was to aggregate the current knowledge on the status of basil production in aquaponic systems by identifying the different aquatic organisms cultured with basil and hydroponic subsystems cultured with basil species/varieties and address research gaps. Of the 100 reviewed publications, about 90% of the reviewed publications used sweet basil (Ocimum basilicum L.) and only three publications used a different basil species; holy basil (Ocimum tenuiflorum), lime basil (Ocimum americanum), or lemon basil, (Ocimum africanum). Of the publications that used sweet basil, Genovese was the most commonly used variety (21 articles), followed by Italian large leaf (6 articles) and purple ruffles (4 articles) varieties. Between the reviewed publications, 38.7% used deep water culture (DWC), 31.1% used media bed (MB), and 17.9% used nutrient film technique (NFT) to grow basil. Tilapia was the most commonly cultured species with basil in aquaponic systems (44%), followed by catfish (14%) and carp (9%). The amount of feed for tilapia Oreochromis sp. cultured as a function of grow space area ranged between 20.3 and 81.6 g feed/m²/day. Values ranged between 29.2 and 68.9 g feed/m²/day while culturing Pangasius sp., 20–25 g feed/m²/day while culturing catfish (Ictalurus sp.), and 4.4–16.9 g feed/m²/day while culturing carp (Cyprinus sp.). The variability in the fish feed-to-plant ratio suggests a need for establishing a recommendation for a species-specific optimal feed input that supplies sufficient nutrients for basil. The current review suggests further investigations comparing different basil varieties, cultivating different basil cultivars with different fish or crustacean species, using alternative hydroponic types, and evaluating feed inputs for establishing a recommendation for species-specific optimal conditions in aquaponic systems.