Resumo

MARTINS, Mônica Cagnin et al. Sowing date, planting density and vegetative performance of soybean cultivars. Sci. agric. [online]. 1999, vol.56, n.4, pp. 851-858. ISSN 0103-9016.  http://dx.doi.org/10.1590/S0103-90161999000400012.

The present research was carried out in Piracicaba, SP, Brazil, to evaluate vegetative performance of three soybean cultivars at two sowing dates, at five plant densities. The cultivars used were: IAC-17, IAC-12 and IAC-19, with early, semi-early and medium maturation, respectively, sown at the typical planting date and late date. Each cultivar was sown at densities of 10, 15, 20, 25, and 30 plants.m^-1. Experimental plots with five rows spaced 0.50 m and 5.0 m long were randomized in blocks, using a factorial design (3 cultivars x 5 plant densities), with three replications. Plant final height, main stem diameter, number of nodes, and number of branches per plant were evaluated. Reduction of cultivars cycle for the late sowing date occurred mainly during the reproductive phase. Independently of the planting date, the increase in plant density, implyed in an increased final plant height and in decreasing main stem diameter and number of branches per plant. Number of nodes in the main stem was reduced with the delay of the planting date.

Palavras-chave : soybean; cultivar; planting date; plant density.