GERMINATION OF ACHENES OF BIDENS PILOSA L.

Abstract
Summary: The germination of achenes of Bidens pilosa L. was enhanced by light. Under continous fluorescent light germination was 80–90%. Germination was also induced by brief exposures (2 minutes or longer) to blue, green, red and far‐red light. The promotive effect of an irradiation with red was not reversed by far‐red. Cold treatments also enhanced germination. A low concentration (5 ppm) of 6–benzyladenine stimulated germination of the achenes in darkness and also enhanced the proportion of germination in combination with red and far‐red irradiation.