Germination tests on thirty-two East African weed species

Abstract

The seeds of thirty-two species of common East African weeds were set to germinate in the light and in the dark. Eighteen species with more than 40% germination in the light were also germinated in leaf shade and in neutural shade of equal intensity. Germination of fifteen of these was inhibited by darkness, and of sixteen by leaf shade, with complete inhibition in six species. A high degree of dormancy was found in fourteen species. Only one species in this group responded to alternate wetting and drying of the seeds. In eight species dormancy was less in older seeds. The ecological implications of the results are briefly discussed, and comparisons made with temperate weeds.