INFLUENCE OF SOWING DENSITY AND FUNGICIDE APPLICATION ON RAPESEED YIELD AND YIELD COMPONENTS

To determine the optimal sowing density and fungicide application for rapeseed crops in the agroecological conditions of north-western Croatia, exact micro-trials were set up at the experimental facility of the Faculty of Agriculture in Zagreb in the period 2005-2007. The trial involved five sowing density (30, 50, 70, 90 and 110 germinated seeds m-2) and crop treatment with fungicides (metconazole 60 g l-1, preparation "Caramba") as well as no treatment. The hybrid Elvis served as trial crop. Yield and yield components were significantly influenced by the year and sowing density. In the three-year average, the significantly highest yields of seed (4.70 t ha-1) and oil (1.85 t ha-1) were achieved at the sowing density of 70 germinated seeds m-2, i.e., plant density at harvest of 35 plants m-2. Sowing density increase above 50 germinated seeds m-2caused a significant decrease in the number of fertile branches per plant and the number of siliques per plant whereas the 1000 seed weight remained stable at all sowing densities. Fungicide application had no significant effect on rapeseed yield and yield components.