Effect of plant density on yield of two soybean cultivars in Sari region, Iran

This experiment was carried out in order to investigate the effect of plant density on yield of two soybean cultivars as factorial based on a randomized complete block design with three replications at Khazarabad, Sari region in 2007. Factors were plant distance at three levels (5, 10 and 15 cm), row distance at two levels (40 and 50 cm) and two cultivars (Sahar and Sahel). Results showed that the effect of plant distance, row distance, cultivars, interaction of plant distance and cultivar, interaction of plant distance and row distance and triple interaction of plant distance, row distance and cultivar was significant on seed, oil and protein yields. The maximum yield (5681 kg) was observed for interaction of plant distance of 5 cm and row distance of 40 cm. The most grain yield (6569 kg) was produced at plant distance of 5 cm and row distance of 40 cm for Sahel cultivar and the least grain yield (4796 kg.ha-1) was produced by plant distance of 15 cm and row distance of 50 cm for Sahel cultivar. However, the most oil percentage (54.57%) were obtained at plant distance of 15 cm and row distance of 50 cm in Sahel cultivar and it was 57.54% for Sahar cultivar at plant density of 5×50 cm. Therefore, the highest grain yield was produced for Sahel cultivar at plant density of 5×40 cm and for Sahel cultivar at density of 15×40 cm.
In conclusion, row and plant distances and the type of cultivar had significant effect on yield and yield components of soybean at Sari condition, so that each cultivar produced higher yield in a specified density.