Patterns of seed weight distribution and germination with time in a weedy biotype of proso millet (<i>Panicum miliaceum</i>)

Abstract

Three plants from each of 10 populations of the black biotype of proso millet (Panicum miliaceum) were grown in a common garden in London, Ontario. Seeds were collected from individual plants as they ripened. Each seed was identified as to location on the plant and weighed separately. Mean seed weight decreased over the growing season, both on individual inflorescences and on entire plants. Despite this trend, seeds at the upper end of the weight range were produced throughout the season. The decline in the mean resulted from an increasing proportion of smaller seeds. There was also increased variability in seed weight later in the growing season. In subsequent germination tests there was no discernable relationship between total percent viability and date of seed ripening. Total percent viability was above 70% for each sampling date. Key words: seed weight, positional effects, proso millet, germination, seasonal variation.