Effect of Microalgal Biostimulants (Chlorella vulgaris and Arthrospira platensis) on the Growth Performance of Pak Choy in a Hydroponic System

The growing interest in sustainable agricultural practices has led to an exploration of biostimulants. This study investigates the impact of microalgae as biostimulants in a hydroponic system, using Pak Choy as the model plant. Three hydroponic setups were employed: a control system containing tap water with hydroponic fertiliser, and two experimental systems supplemented with microalgae without fertiliser— Arthrospira platensis and Chlorella vulgaris, respectively. The control group produced the tallest plants and the highest fresh weight, exceeding the other treatments by 106.65 mm in height and 9.344 g in fresh weight. Between the two microalgal treatments, Chlorella vulgaris produced higher plant height, fresh weight and improved physicochemical indicators compared to Arthrospira platensis. While both microalgal treatments yielded lower biomass than the fertilised control, they were able to sustain plant growth in the absence of synthetic fertiliser.