Sowing density associated with the agronomic performance and linear relationships between the morphological traits of sunflower

Abstract

The objective of this work was to evaluate the effect of sowing density on sunflower morphological traits and on the linear relationships between these traits under second-crop conditions, in addition to identifying the traits that can assist in the indirect selection of sunflower hybrids. The experimental design was in randomized complete blocks, with four replicates and six treatments (sunflower sowing densities: 20, 30, 40, 50, 60, and 70 thousand plants per hectare). The sowing density of 51.45 thousand plants per hectare provides the maximum yield per area under second-crop conditions. Sowing density negatively influences the magnitude of the linear associations between the traits number of achenes and individual yield per plant and between plant height and thousand-achene mass. In addition, under a high sowing density, the association between plant height and thousand-achene mass becomes negative. The traits number of achenes per capitulum and capitulum diameter show the highest magnitudes of linear association with individual yield per plant and, therefore, can be used for the indirect selection of sunflower hybrids.