Evaluation of Soybean Cultivars in Different Planting Arrangements and Densities in Golestan Province of Iran

To evaluate soybean cultivars in different planting arrangements and densities، three field experiments were conducted in 2006 and 2007 growing seasons in Gorgon agricultural research station. Three soybean cultivars; Sepideh، Sahar and Katoul were planted in different planting arrangements and densities on one and twin rows on beds with 50، 75 and 85 cm row spacings. Three separate experiments were carried-out as split-plot arrangements in randomized complete blocks design with three replications، for each soybean cultivar. Combined analysis of variance revealed significant differences between two growing seasons. All soybean cultivars had less seed yield in 2007 growing season. Sepideh performed significantly different in different row spacings and produced the highest seed yield (2459 kg ha-1) in twin rows with 75 cm row spacing and 500000 plant ha-1. Sahar، however، produced the highest seed yield (2560 kg ha-1) in one rows with 50 cm row spacing. It also had the highest seed yield with 300000 plant ha-1. Katoul produced the highest seed yield (2992 kg ha-1) in twin rows with 75 row spacing. It can be concluded that soybean cultivars responded differently to different planting arrangements and plant densities. Therefore، to obtain the seed yield potential، each cultivar must be planted in its suitable planting arrangement and density.