Sowing date and multivariate analisys of yield and physiological components in elite wheat genotypes

The objective of this study was to evaluate the effect of sowing date on yield and physiological components aiming to identify the period that enhances the increment of the components and analyze via multivariate techniques the dissimilarity and the relative contribution of traits in elite wheat genotypes. The experiment was carried out during the 2014 agricultural year in a randomized block design (11 wheat genotypes x 2 sowing dates) with three replications. Sowing in May (date I) increases the spike weight and grain weight per spike, grain yield, thousand grain weight, first germination count, germinated seeds, and seedling dry weight. Genetic dissimilarity discriminated genotypes into two major groups, being TBIO Mestre and BRS 327 the most dissimilar genotypes. The largest relative contribution for the discrimination of genotypes was expressed by the spike insertion height, germinated seeds, number of grains per spike, and plant height, explaining 61.8% of the total variation.