Stability and Adaptation of Soya Strains Based on different Models in the North and Northeast Regions

In Brazil, soya is the most important annual crop and is grown in a variety of environmental conditions. The environmental effect segregates the growing regions, where each one has its own peculiarities, and it is therefore the responsibility of genetic improvement programmes to meet the demand for new cultivars that overcome the instabilities and take advantage of the beneficial conditions of these environments. The aim of this study was to assess the productivity, adaptation and stability of soya strains in VCU trials. A randomised block design with three replications was used, in which six strains and two commercial cultivars were part of the trials in the cities of Cariri-TO, Caseara-TO, Aparecida do Rio Negro-TO, Porto Nacional-TO, Balsas-MA and Barreiras-BA, in the 2022/23 harvest. The REML/BLUP variational modelling method was used to analyse the data, estimate genetic parameters and predict genotypic values via MHPRVG. Significance was observed for genotypic effects and double interaction. The average heritability was adequate for the type of data set, which showed high accuracy. The genotype x location interaction showed a high coefficient of determination and the opposite was observed for the correlation, demonstrating the great influence of this effect on the results, thus highlighting its importance for the study, according to genetic parameters estimated via various models. According to the BLUPs for MHPRVG, the SOY 03 strain showed the best behaviour compared to the others and could be used as a cultivar.