Seed weight, intraspecific competition, and plant performance in Abutilon theophrasti

Seed weight of Abutilon theophrasti Medic, varies among populations and with the light conditions of the parent plants. In this study, the impacts of seed weight variation on seed germination and plant growth were investigated. Variations in seed weight did not result in any significant difference in the germination ability of seeds. The enhanced germination associated with large seeds produced by plants in shaded conditions found in previous studies were more likely the result of interpopulational variation or difference in maternal environments. The leaf chlorophyll content of young seedlings and the total leaf area of plants at harvest tended to increase with increasing original seed weight of the plants. Although the aboveground biomass of a plant was not affected by its original seed weight, the performance of the plant depended significantly on the total original seed weight of the neighbouring plants. Key words: seed weight, germination, competition, Thiessen polygon, Abutilon theophrasti.