Influence of seed rate and planting geometry on growth and yield of soybean (Glycine max) varieties

A study was conducted during 2015 and 2016 Rudrur, Nizamabad, Telangana, to study the response of 2 varieties, viz. ‘JS 335’, ‘Asb 22’, and 7 planting geometries vis-a-vis seed rate (30 cm × 10 cm, 30 cm × 15 cm, 30 cm × 30 cm, 45 cm × 10 cm, 45 cm × 15 cm, 45 cm × 30 cm, 45 cm × 45 cm) in split-plot design, replicated thrice. Seed yield was significantly influenced by varieties and plant geometries. Between the 2 varieties studied, ‘Asb 22’ was found superior to ‘JS 335’ with mean seed yield of 2808 kg/ha, being 12% higher over existing variety ‘JS 335’ with mean seed yield of 2209 kg/ha. Among plant geometries, 30 cm × 15 cm resulted in significantly higher yield (2,874 kg/ha) closely followed by 45 cm × 10 cm (2,675 kg/ha) and 45 cm × 15 cm (2,614 kg//ha) over the existing spacing 30 cm × 10 cm (2,500 kg/ha ). Yield reduction with 30 cm × 10 cm was to the extent of 6-12% compared to plant geometry of 30 cm × 15 cm or 45 cm × 10 cm. Variety ‘Asb 22’ was found economically superior with net returns of 58,519/ha and benefit: cost ratio 2.56, being 40% higher over existing variety ‘JS 335’ with net returns of 41,774/ha and benefit: cost ratio of 1.86. Plant geometry with 30 cm × 15 cm proved superior with net returns 59,361/ha. However, cultivation of soybean with plant geometry of 45 cm × 10 cm or 45 cm × 15 cm was on par with 30 cm × 15 cm, with net returns of 53,569/ha and 53,444/ha, respectively. The study revealed that, present variety ‘JS 335’ of soybean can be replaced with variety ‘Asb 22’ with plant geometry of 30 cm × 15 cm or 45 cm × 10 cm or 45 cm × 15 cm over existing geometry of 30 cm × 10 cm.