Agronomic characteristics of sunflower genotypes according to plant population

The agronomic characteristics of sunflower genotypes were evaluated under different plant populations. The experiment was performed at the IFMT experimental field, campus Campo Novo do Parecis, Brazil, between February and June 2015. The experimental design comprised randomized blocks, in a factorial 5 x 5 arrangement, with five sunflower genotypes (AGUARA 04, GNZ NEON, HELIO 251, SYN 045 and SYN 3950HO) and five plant populations (30,000; 37,500; 45,000; 52,500; 60,000 plants ha-1), with 3 replications. Plant height, stem diameter, capitulum height, capitulum size, achene mass per capitulum, mass of one thousand achenes and achene productivity were assessed. Increase in plant and capitulum height, reduction of stem diameter, capitulum size, achene mass per capitulum and mass of one thousand achenes occurred with increase of plant population. Productivity is correlated with the mass of achene per capitulum and with mass of one thousand achenes. The population of 47,150 plants ha-1 provided the highest achene productivity.