PLANT-DENSITY AND ARRANGEMENT IN SUNFLOWE R

A serie of trials was conducted in order to evaluate the effect of fac tors such as cultivar, planting date, fertility level and weed control , which affect the sunflower crop response to plant density and arrang ement. The trials were carried out at Eldorado do Sul and Passe Fundo, respectively in phisiographic regions of Depressao Central and Planal to Medio, in the state of Rio Grande do Sul, Brazil. The short season cultivars with low height enabled the utilization of higher plant dens ity than long season cultivars with tall height. The short season cult ivars with early planting date (late July) and more fertility in the s oil provided higher densities. The grain yield did not vary with the u tilization of distinct inter-row spacings. Oil content of Contisol 711 cultivar increased with density enhancement. However, for all cultiva rs tested oil content didn't modify with change in plant arrangement. In weed infested areas, narrower spacings were more efficient to reduc e competition.