RATE AND DURATION OF DRY MATTER AND OIL ACCUMULATION IN SEEDS OF TWO SUNFLOWER CULTIVARS

The present experiment was carried out at the Estação Experimental Aronômica / UFRGS (Eldorado do Sul, RS), during the 1989/90 growing season. The objective was to determine the rate of dry matter and oil accumulation in the seeds of two sunflower cultivars (Contisol 711 and DK 180) affected by two plant populations (50.000 and 70.000 plants/ha). Samples were composed by eight plants harvested from each sub-plot every seven days beginning at the anthesis stage. Plant population did not affect the rate and the duration of dry matter accumulation. However, grain yield was affected by plant population and sunflower cultivars. The cultivar Contisol 711 had their grains completely filled seven days earlier than the DK 180 cultivar. On the other hand, the cultivar DK 180 showed higher seed filling rate. It was not possible to identify an association of the rate and the duration of dry matter accumulation either with grain yield on oil content.

Helianbhus azmuus L; plant density; oil and dry matter in seeds; grain filling; grain yield