Soybean morphophysiology and yield response to seeding systems and plant populations

Abstract

Soybean (Glicine max [L.] Merr.) is recognized worldwide for its economic importance; it has the ability to adapt to environmental and management changes, particularly when using different spacing and plant populations. This study aimed to investigate the influence of morphological changes of the crisscross seeding system on grain growth and yield. Work was conducted at the Experimental Station of Anapolis, Goiás, Brazil, of the Technical Assistance Agency, Rural Extension and Agricultural Research of Goiás (EMATER) for the 2013-2014 harvest. The experimental design was a randomized block and 2 × 3 × 3 factorial, with four replicates. Treatments consisted of two seeding systems (conventional-in line and crossed-crisscross), three soybean cultivars with different growth habits (‘BRS Valiosa RR’ determined, ‘NA 7337 RR’ semi-determined, and ‘BMX Potência RR’ indeterminate) and three sowing densities (245 000, 350 000, and 455 000 plants ha-1). Results showed that at 50 d after emergence the cross-seeding system showed higher closing among lines promoted by the increase in population. Leaf area and the leaf area index were not affected by the seeding system. Leaf area was lower with increasing plant density with no significant difference in relation to the leaf area index. The cross-system enabled a potential yield of 4504 kg ha-1 corresponding to an approximate 8% increase compared with conventional sowing using equidistant lines with 0.5 m spacing.