Análise da produtividade de cultivares de soja em terras baixas

Abstract

The objective of this study was to analyze the agronomic performance of 20 soybean cultivars in the lowlands by means of the main components method. An experiment was conducted in the experimental area of the Federal University of Pampa, Itaqui-RS campus (latitude 29º09'21''S, longitude 56º33'02''W and altitude of 74m) in the 2017/2018 harvest. The experimental design was a randomized complete block design with three replications, in a two - factorial scheme with 60 treatments consisting of 20 soybean cultivars in three sowing seasons, arranged in plots of 6.75m² (5 rows × 3m in row × 0, 45m between rows). In the evaluation of the adaptability and stability of the genotypes, the principal components method (Centroid) was used, facilitating the discrimination of the genotypes in case of significance of the genotype × environment interaction. The mass of one hundred grains had no significant interaction of genotype × environment. For this variable, in general, the cultivar 68I70 RSF IPRO differed statistically from the others, with a higher mean. The grain yield ranged from 1372.38 kg ha-¹ to 6064.40 kg ha-¹, with an overall average of 2789.08 kg ha-¹. Genotype × environment interaction occurred, with alterations of the rankings of cultivars between environments for the grain yield variable. The cultivars 63I64 RSF IPRO, NA 5909 RG, 68I70 RSF IPRO, 50I52 RSF IPRO, 5855 RSF IPRO, 7166 RSF IPRO, 58I60 RSF showed the highest production averages. The cultivars 63I64 RSF IPRO and 68I70 RSF IPRO presented wide adaptability and stability and high grain yield in the evaluated environments and were positioned close to what would be considered ideal (ideotype I) for the environments analyzed by the main components method. The cultivar 68I70 RSF IPRO can be used in breeding programs, aiming to increase the mass of grains in the lowlands and the cultivar 63I64 RSF IPRO as possible parent for the increase of grain yield.