A strict, one-factorial field experiment with spring rapeseed cv. Licosmos was conducted at the Agricultural Plant Collection (52°9' N; 21°2' E) of Agronomy Department (Warsaw University of Life Sciences) in the years 2002-2003. The aim of the study was to give a detailed analysis of plant yielding depending on different number of plants per 1 m², i.e. 40, 60 and 80 plants·m^-2. Measurements taken covered the evaluation of seed weight per plant and elements of yield structure, i.e. number of pods per plant, number of seeds per pod and thousand seed weight. The measurements were taken from single plants from a randomly selected row in four replications, separately on the main stem and primary and secondary branches. Number of plants per 1 m² within the range 40-80 plants·m^-2 significantly differentiated seed weight per individual plant, which indicates the strong adaptability of spring oilseed rape plants to different canopy densities. Larger seed weight per plant was observed at a smaller number of plants per 1 m², which resulted mainly from a higher number of pods. Other elements of yield structure, i.e. number of seeds per pod and thousand seed weight, turned out to be more stable and only to a slight degree dependent on the canopy density.

31-41