Increasing salt stress and water scarcity necessitate research on plant salinity tolerance. This study investigated the effects of biochar crossandra (Crossandra infundibuliformis) under saline conditions. Three biochar rates (0%, 15%, 25%) were incorporated into commercial substrates, with salinity treatments of control, medium, and high at 0.2 dS∙m-1, 2 dS∙m-1, and 4 dS∙m⁻¹ respectively. Growth parameters (growth index, chlorophyll content, number of flowers), biomass, and physiological responses (photosynthesis, transpiration, stomatal conductance rate) were evaluated over time. The results showed crossandra tolerated salinity up to 4 dS∙m⁻¹ with minimal effects on flower production, biomass, and physiological responses, though growth index and SPAD values declined. At 2 dS∙m⁻¹, 15% biochar improved growth index, SPAD, number of flowers, biomass, and physiological rates comparable to controls. These results suggest biochar can mitigate salinity effects for crossandra plants.
