EFFECT OF FERTILIZER APPLICATION ON DENSITY, DRY MATTER AND SEED CHARACTERISTICS OF GARDEN CORNFLOWER (Centaurea cyanus L.) AND CORN SPURREY(Spergula vulgaris L.)

The research was conducted at the Agricultural University of Timiriazev, Moscow, and University of Mohaghegh, Ardabili, Iran, to determine the effect of fertilizer application on density, dry biomass and seed characteristic of garden cornflower (Centaurea cyanus L.) and corn spurrey (Spergula vulgaris L.) during 2004- 2006. The analysis show that N and P application increased density and dry biomass of garden cornflower compared with no fertilizer (control), while density and dry biomass of corn spurrey was decreased. The results show that density of corn spurrey reduced as density of garden cornflower increased. After one year, only 11.5 and 30% seeds of garden cornflower and corn spurrey germinated, respectively. Conditions during maternal plant growth affected the seed characteristics of the two species. Seed germination of garden cornflower and corn spurrey in laboratory increased with P application compared with control and N application. These findings suggest that fertilizer application influences weeds, not only for weed density and biomass, but also by affectingseed characteristics.