Agronomic performance of soybean genotypes in Brazil sub-subtropical climate

Soybean is the main economic crop of Brazilian agribusiness, and the extreme south of the country is considered a new agricultural frontier. The objective of this study was to evaluate the components of the yield and agronomic performance of soybean genotypes in the south of Rio Grande do Sul as well as to verify the linear relationships of the measured characters. The study was carried out in the municipality of Pelotas, Rio Grande do Sul, Brazil, in the crop harvest 2016. The experimental design was a randomized complete block design, containing 25 soybean genotypes arranged in four replicates. The experimental units were composed of five sowing lines, spaced by 0.45 meters and three meters in length. The measured characters were: first pod insertion height, plant height, number of branches, length of branches, number of pods in the main stem, number of pods in the branches, number of pods with one, two, three and four seeds, contributing to the pod mass with one, two, three and four seeds. The data were submitted to analysis of variance at 5% of probability, where for the significant characters the averages were compared by the Duncan’s test and Pearson's linear correlation was performed in order to identify the tendency of association among the measured characters. The genotypes DM 6159IPRO, BS2606 IPRO, BMX Magna, BMX Potência, TMG7062 IPRO, LG 60163 IPRO revealed superior characters, which can positively influence grain yield. There is a correlation among the morphological characters of the soybean cultivated in southern Brazil between the number of pods in the main stem and the number of pods in the branches, as well as between the number of pods with two seeds and the number of pods in the branches.