DefinePK

Abstract

Abstract | Algal extracts are emerging as a promising, sustainable solution for enhancing plant growth and physiological performance. This research investigated the biostimulatory impacts of algae extracts of Spirulina platensis and Sargassum polycystum on the photosynthetic efficiency and nutrient uptake in wax apple seedlings. Uniform size of wax apple seedlings was foliar sprayed weekly for eight weeks, using aqueous algal extract at various concentration of S. platensis extract; T0 (0.0%), T1 (2.5%), T2 (5.0%), T3 (10.0%) and various concentration of S. polycystum extract; T4 (2.5%), T5 (5.0%), T6 (10.0%) as well as T7, 5.0% (1:1) of mixed extract. There were five replicates of each treatment, which was conducted using a Randomized Complete Block Design (RCBD). The results demonstrated distinct increase in chlorophyll a, chlorophyll b and carotenoid in T3 (10.0% S. platensis extract) treatment with 59.34%, 50.98% and 11.27% respectively over control, resulting in the highest total chlorophyll. While T6 (10.0% S. polycystum extract) gave the greatest SPAD reading with 83.65% increase. At the meantime, the T3 also showed the significant increase by 6.84% and12.38% respectively in Fo and Fm value. Fv/Fm and Fv/Fo ratios were also significantly enhanced by the similar treatment with values of 0.81 and 2.85, respectively. An increase in stomatal conductance was seen as a result of algal extract application, specifically in T3 (55.96%), followed by T5 (5.0% S. polycystum extract) (52.43%) and T6 (50.74%), respectively. Additionally, algal extracts were found to enhance the nutrient uptake in wax apple seedlings. T3 signified the most improved uptake of N, P, K, Cu, Fe and Mn by 56.03%, 130.0%, 106.83%, 75.0%, 117.78% and 145.0% accordingly, compared to control. In contrast, the greatest uptake of Ca and Zn can be seen in T6 treatment with 104.55% and 66.67% respectively over control. However, both T3 and T6 exhibited similar influence in Mg uptake. These findings provide further evidence that extract derived from S. platensis and S. polycystum are efficacious in enhancing physiological parameters critical for plant growth. These extracts enhance photosynthetic efficiency, nutrient absorption, and stomatal function, providing a sustainable and environmentally benign method for enhancing the production of high-value crops such as wax apple, hence improving agricultural output and environmental resilience.