Growth and Yield Responses of Dragon Fruit to Diverse Growing Media in Rooftop Gardens

Dragon fruit, a demanding exotic fruit, is gaining popularity among tropical urban rooftop gardeners. Nevertheless, suitable growing media for successful rooftop gardening of dragon fruit remain unexplored. Therefore, this study aimed to identify an optimal substrate for dragon fruit production on rooftops. Hence, a pot experiment was conducted on the roof of a four‐story building following a randomized complete block design with three replications. The 2‐year‐long (2020–2022) experiment included seven different combinations of soil, cocodust, and biochar plus vermicompost as a common manure. While T 7 (30% soil + 25% cocodust + 25% biochar + 20% vermicompost) had higher branch count (24.67 pillar −1 ) in the first year, T 2 (80% cocodust + 20% vermicompost) outperformed all other treatments, with 29.00 branches pillar −1 in the second year. Accordingly, the T 2 treatment resulted in the highest fruit count (54.67 pillar −1 ), heaviest fruit (365.80 g, 1.4 times greater than the control), and maximum yield (9.50 kg and 20.02 kg in the consecutive seasons, respectively). Moreover, T 2 significantly improved edible portion, TSS, and vitamin C contents and exhibited the highest benefit‐cost ratio (4.17) compared to control. Thus, a growing medium comprising 80% cocodust and 20% vermicompost can be recommended for dragon fruit cultivation under rooftop conditions.