The aim of this research was to evaluate the performance of small-scale vertical hydroponic structures compared to indoor planting in soil under different light conditions. Fordhook Giant Swiss chard (Spinacea oleracea) was grown for 2 cropping seasons. It was hypothesised that there would no significant difference in the biometric attributes of the plants grown hydroponically and those grown in soil under different light conditions. Plants grown hydroponically had a significantly higher relative growth rate than plants grown in soil (0.090 g.g-1.day-1 vs 0.080 g.g-1.day-1 in cropping season one (CS1), and 0.085 g.g-1.day-1 vs 0.079 g.g-1.day-1 in CS2), p = 0.030 in CS1 and p = 0.011 in CS2. There was a statistically significant difference between the total leaf area per plant of plants grown hydroponically and those grown in soil (1 263.39 mm2 vs 914.32 mm2 in CS1, and 1 286.98 mm2 vs 896.63 mm2 in CS2), p < 0.01 in both cropping seasons. The results indicate that small-scale vertical hydroponic structures can be used as an applicable alternative to conventional potting systems in indoor planting. The study has contributed new quantitative information about the performance of vertical hydroponic structures, which may aid potential farmers in decision making.

Keywords: vertical farming; hydroponics; indoor farming; grow lights; relative growth rates