Standardization of soybean row spacing based on morpho-physiological characters

A field experiment was conducted during December 2008 to April 2009 to investigate the effect of genotypes and row spacing on morpho-physiological characters, yield attributes and yield of soybean with three row spacing of 25, 30 and 35 cm. The experiment was laid out in two factor randomized complete block design with four replications. Branch number plant⁻¹, leaf area plant⁻¹, total dry mass plant⁻¹, absolute growth rate, relative growth rate, pod number plant⁻¹, seed yield plant⁻¹ and harvest index were increased with increasing row spacing while reverse trend was observed in plant height and leaf area index. Results revealed that narrow spacing performed better in seed yield than wider spacing in soybean. The genotype having lower leaf area requires narrows row spacing and vice versa. On an average over the genotypes, the row spacing of 30 cm showed the highest seed yield in soybean under Bangladesh conditions. The optimum row spacing for higher seed yield of genotype BAU-21 and Shohag was 25 cm while optimum row spacing for genotype BAU-70 was 30 cm. Among the different genotypes, BAU-70 produced the highest seed yield both plant⁻¹ and ha⁻¹ due to its larger photosynthetic area.