Adequação do arranjo de plantas em cultivares de soja de porte alto

Abstract

Due to its characteristic of morphological suitability to the different farming environments, and to the management used, denominated of plasticity, the soybean (Glycine max L.) tolerates diverse arrangements of plants. Depending on the arrangement adopted, the plants may respond differently to the uptake of solar radiation, the absorption of water and nutrients. In addition, new dynamics of entry of defensive canopies occurs as well as competition with weeds. The objective of this work was to evaluate the agronomic performance of four soybean genotypes, TMG 7062 INOX IPRO e LG 60163 IPRO and two pre-commercial lines codified from, CI 53 and CI 21 RR. These were conducted at three plant densities, 200, 300 and 400 thousand ha-1 plants and two different row spacings, 0.25 and 0.50 m. The experiment was conducted at the annual crop experimental station of the Universidade Tecnológica Federal do Paraná, Câmpus Dois Vizinhos, in the 2016/2017 crop. The variables analyzed were lower third petiole, medium third petiole, upper third petiole, bedding, plant height, first pod insertion, branching, number of plant pods, number of pods of three grains, number of pods of two grains, number of pods grains per plant, number of grains per pod, mass of one thousand grains and productivity. The experimental design was a randomized block design, with three replications. Data were submitted to analysis of variance and compared in a two-factor scheme, by Scott Knott, at a 5% probability. Lineage CI 21 showed higher productivity in the spacing of 0.5m and in the larger population. The yield of the lineage CI 53 was not affected by the population and spacings tested. The cultivar TMG 7062 did not present a productivity difference for the factors studied. For cultivar LG 60163, the 0.25m spacing was the most productive, in the population of 300.000 ha-1. The responses as a function of line spacing and plant population are variable among cultivars, even if they are tall.