By 2050 it is estimated that the human population of the Earth will be approximately 10 billion people. In order to improve input use efficiencies and mitigate greenhouse gas emissions, hydroponic production systems can represent an alternative to the conventional methods of food production. Traditionally, leafy greens and herbs have always been associated with indoor agriculture and continue to be extremely popular among vertical farmers. More than half of indoor and vertical farms produce leafy greens. Among the grown herbs in vertical farms, basil (Ocimum sp.) represents one of the most popular choices and is cultivated for culinary purposes as fresh herb or dried spice. It is mainly produced hydroponically or semi-hydroponically with very short growing cycles (usually 10-20 days after germination) and are considered the functional food of the 21st century. Our objectives were to quantify productivity and characterize growth of basil cultivars grown in stacked hydroponic production systems. Twelve basil cultivars were chosen. Seedlings were transplanted into deep water culture (DWC) systems and grown for several weeks. Depending on cultivar, a delayed harvest time was observed with 35 to 38 days of growth after sowing seed. Basil cultivars differed greatly in fresh weight from 2.1 to 3.2 kg m-2 after one cut. The fresh weight showed a correlation with transpiration rate and stomatal conductance. In addition, two cultivars with the highest yield displayed the highest concentration of mineral contents. Further investigations are needed to analyse essential oil composition in order to determine cultivar with a positive nutritional value.
