Drench of humic acid mitigate the adverse impacts of alkalinity on rose

Abstract

Abstract Alkaline stress is a major environmental factor that limits the growth and productivity of rose plants. Humic acid (HA) is a natural substance that has been shown to have various beneficial effects on plant growth and stress tolerance. Roses (Rosa hybrida L.) are among the world's most important and popular cut flowers, dominating the cut flower export market. This study investigated the effects of HA application on the physiological and biochemical properties of rose plants grown under alkaline conditions. A randomized complete design with three replicates was used. Each replicate consisted of two pots containing a single rose plant. Humic acid was applied at 0, 500, 1,000, and 2,000 mg L-1 through drenching at 15-day intervals for two months. Plants treated with 1,000 mg L-1 HA exhibited significantly higher levels of total protein, proline, catalase activity, guaiacol peroxidase activity, and antioxidant capacity. Control plants (receiving no HA) showed the highest levels of malondialdehyde and electrolyte leakage, indicating greater cellular damage. Plants treated with 500 mg L-1 HA displayed the highest sugar content and ascorbate peroxidase activity. Overall, the results of this study suggest that HA application can be an effective strategy to improve the tolerance of rose plants to alkaline stress and enhance their growth and productivity in alkaline soils.