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Abstract

The aim of this study was to assess the performance of leaf area during the development of dual purpose wheat genotypes when subjected to different seeding densities and defoliation managements. The experiment was conducted in 2014 growing season in experimental area belonging to the Breeding Lab and Plant Production of the Federal University of Santa Maria Campus Frederico Westphalen-RS. The experimental design was a randomized complete block in a factorial treatment design, as follows: five genotypes (BRS Figueira, BRS Guatambu, BRS Tarumã, BRS Umbu and BRS 277) × five seeding densities (75; 150; 225; 300; 375 plant m-2) × four defoliation managements (without cut. one cut. two cuts and three cuts) arranged in three replications. The cuts were made when the plants reached 30 cm, leaving 10 cm for regrowth. Leaf area is influenced by defoliation management seeding densities and dual purpose wheat genotype. Increased in seeding density reduces leaf area in all genotypes. The larger leaf area at tillering was obtained at the density of 300 plant m-2 to management with three cuts for the genotypes BRS Tarumã, BRS Umbu, Guatambu BRS and BRS Figueira. The density of 300 plant m-2 provide increase on leaf area in flowering stage for BRS Umbu, BRS Guatambu and BRS 277 genotypes in all defoliation managements. Leaf area reduces in the grain filling when seeding density is increased for all defoliation managements in the genotypes BRS Tarumã, BRS Umbu and BRS 277.