Effect of plant arrangement on grain yield, yield components, oil content and weed control in sunflower

Abstract

With the objective of evaluating the effect of plant arrangement on grain yield, yield components, oil content and on weed control, a research was conducted at Eldorado do Sul, RS, Brazil, during the 1987/88 growing season. Three plant densities (30.000; 50.000 and 70.000 plants/ha) and three row spacings (0,4 and 1,0 m) were tested with and without weed control. Contisol 711, a short season cultivar was used. Plant density and row spacing did not affect significantly weed dry weight. Number of grains per head and average grain weight decreased as plant density increased. On the other hand, grain yield and oil content increased as plant density increased from 30.000 to 70.000 plants/ha. Narrow spacing increased grain yield only when weeds were not controled.