Optimizing growth and flowering in petunia hybrida through biochar enhanced potting media

This study, investigates the effect of biochar based potting media on growth and flowering of Petunia hybrida conducted from November 2024 to February 2025 at ASPEE College of Horticulture, Navsari Agricultural University, Gujarat, India. Evaluated the impact of seven potting media on the growth and flowering of Petunia hybrida. Seven treatments included T1 (Sand + Vermicompost + Biochar 1:1:0.1 v/v/v), T2 (Sand + Vermicompost + Biochar 1:1:0.2 v/v/v), T3 (Sand + Vermicompost + Biochar 1:1:0.3 v/v/v), T4 (Cocopeat + Biochar 1:0.1 v/v), T5 (Cocopeat + Biochar 1:0.2 v/v), T6 (Cocopeat + Biochar 1:0.3 v/v), T7 (Cocopeat + Vermicompost 2:1 v/v). At 90 days, plants grown in Cocopeat + Biochar 1:0.3 v/v (T6) achieved maximum plant height (25.31 cm), number of leaves/plant (765.68), fresh weight of shoot (120.20 g/g/plant) and dry weight of shoot (12.25 g/g/plant), fresh weight of leaf (70.16 g/g/plant), dry weight of leaf (11.69 g/g/plant). Root measurements in T6 were also notable, with fresh weight (7.63 g/g/plant), dry weight (1.52 g/g/plant), longest root length (60.33 cm), root diameter (0.98 mm), and root count (30.53). While the maximum flower bud diameter (5.91 mm) and flower diameter (5.78 cm) were observed in T6. Additionally, T6 yielded the total leaf area (46.37 cm²), net assimilation rate (0.53 x 10-3 g m⁻² day⁻¹), and relative growth rate (1.935 x 10-2 g g⁻¹ day⁻¹). This treatment also showed the lowest root-shoot ratio (0.154), indicating its effectiveness for robust plant growth. This study demonstrates that biochar-based potting media, especially cocopeat + biochar (1:0.3 v/v), significantly enhance growth and flowering in Petunia hybrida.