StimBlue+- mediated modulation of growth and phytochemical traits in Dasispermum suffruticosum for sustainable nutrition and health.

Dasispermum suffruticosum (P. J. Bergius) B. L. Burtt is an aromatic halophyte recognized for its diverse phytochemistry and medicinal plant potential. Despite its potential value, limited scientific information is available regarding its agronomic performance and phytochemical responses. This study investigated the morphological, mineral, and phytochemical responses of D. suffruticosum to gradient dosages of StimBlue+, a seaweed-derived biostimulant, applied via foliar spray (2.5, 5.0, and 7.5 mL/L) and growing-medium drenching (5.0, 7.0, and 9.0 mL/L), alongside an NPK fertiliser control. Two sequential trials were conducted under semi-controlled glasshouse conditions using a Randomised Complete Block Design (RCBD). Morphological parameters and mineral uptake were assessed over 12 weeks, while phytochemical analyses, including (TPC), and antioxidant capacity (ABTS, FRAP, and DPPH) were conducted for 10 weeks on the three best-performing treatments following the first trial. Growing medium drench at 7.0 mL/L (T5) produced significantly higher stem diameter (1.24 mm), plant height (7.29 cm), number of leaves (8.87), and chlorophyll content (1.30 mg/ m2) than the control (p ≤ 0.05), while foliar spray at 2.5 mL/L (T1) recorded the highest root development. StimBlue+ treatments showed descriptively higher concentrations of several minerals including leaf K, Mg, Ca, Na, Fe and Zn compared with the control. T1 also recorded the highest TPC (20.25 and 8.71 mg GAE/g DW) and ABTS (171.32 and 122.90 μmol TE/g DW), FRAP (110.86 and 63.62 μmol AAE/g DW), DPPH (68.14 and 43.77 μmol TE/g DW), in leaves and roots, respectively. These findings provide preliminary baseline phytochemical and mineral data for D. suffruticosum and indicate its potential as a candidate functional food, with low-dose foliar StimBlue+ application emerging as a promising treatment warranting further investigation, including replicated trials and targeted bioactive compound characterisation, before nutraceutical application can be confirmed.