ASHS 2024 Conference

Given the escalating demands for water and the accompanying scarcity, enhancing water use efficiency (WUE) in horticultural practices has become imperative. Research has revealed that both biochar (BC) and seaweed extract biostimulants (BS) significantly enhanced WUE in plant growth, presenting promising avenues for sustainable agricultural advancement. This study aimed to investigate the synergistic effect of BC and BS on WUE for celosia (Argentea cristata) and gomphrena (Gomphrena globose) production. Three factors were included in this experiment including 1) mixed hardwood biochar blended with commerical substrate mixes (CS) at 0%, 10%, 15%, and 25% 2) 60% or 80% irrigation and 3) 0 or 5 mL BS(seaweed extract). The physical properties of substrate, including container capacity (CC), total porosity (TP), air space (AS), bulk density (BD), and water holding capacity (WHC), and chemical properties including leachate pH and electrical conductivity (EC) were measured. Plant growth parameters including growth index (GI) and leave greenness (indicated with SPAD value), biomass, and numbers of flowers were measured biweekly. Photosynthesis rate, transpiration rate, and stomatal conductance rate were measured at 6, 7, 8 WAT. The results showed that BC rates had significant effects on CC, and BD, but no effects on either TP, AS or WHC. Celosia plants grown in the 25% BC mix treated with 5mL BS at 80% irrigation had significantly higher biomass and WUE, and both plants in the same mix (25