Abstract
Calcium is an essential secondary macronutrient involved in membrane stabilization, cell wall development, and intracellular signaling in plants. The present study investigated the concentration-dependent effects of calcium sulphate (CaSO₄) (100 mM, 200 mM, and 400 mM) on seed germination and growth performance of Raphanus sativus under pot conditions. The experiment was conducted using a completely randomized design with three replicates per treatment. Germination percentage and morphological parameters were recorded at 15-60 days intervals. Results revealed that 200 mM CaSO₄ significantly enhanced germination (56.6%) compared to control (40%) and 400 mM (33.3%). Radicle length (2.33 cm), plumule length (5.6 cm), root length (15.06 cm), and shoot length (14.7 cm) were highest at 200 mM treatment. Similarly, leaf number (7.66), flower number (37.66), and seed production (4 seeds per pod) were markedly increased at 200 mM compared to control plants. In contrast, 400 mM CaSO₄ reduced most growth parameters, indicating possible osmotic imbalance at higher concentration. The findings demonstrate that moderate calcium supplementation (200 mM) improves vegetative and reproductive performance of R. sativus, whereas excessive calcium levels adversely affect plant growth. Optimized calcium management may therefore enhance radish productivity under controlled cultivation conditions.