Abstract
The experiment investigated the effect of spacing on roselle growth and calyx yield. The experiment consists of seven spacings, viz., 30 cm × 30 cm (S1), 60 cm × 30 cm (S2), 60 cm × 45 cm (S3), 60 cm × 60 cm (S4), 90 cm × 30 cm (S5), 90 cm × 45 cm (S6), and 90 cm × 60 cm (S7). The experiment was conducted in a randomized complete block design with three replications. According to the study, the shortest duration from sowing to 50% budding (101 days) was recorded at S1, whereas S₇ required the least time to reach 50% flowering (115 days), and to 90% maturity (148 days). The widest spacing (S₇) produced the tallest plants (196.87 cm), number of branches (14.33), number of leaves (134.22), the longest petiole (5.91 cm), petiole weight (24.41 g plant⁻¹), and stem weight (131.39 g plant⁻¹). The highest leaf area index (6.82) was found in S1. Spacing of S₇ also produced the maximum number of fruits per plant (mature-70.41, immature-15.83), largest fruit size (6.46 cm), total fruit weight (93.73 g plant⁻¹), and calyces weight (44 g plant⁻¹). The highest fruit yield (fresh-36.77 t ha⁻¹, dry-2.25 t ha⁻¹), calyx yield (fresh -17.15 t ha⁻¹, dry-0.69 t ha⁻¹), and seed yield (fresh-19.62 t ha⁻¹, dry -1.57 t ha⁻¹) were obtained at S4. Based on the findings, roselle cultivation at a spacing of 60 cm × 60 cm (S4) is optional to achieve maximum calyx yield under Bangladesh conditions.