Abstract
The present investigation was undertaken to make clear the relation between seed development and germination behavior of Rumex obtusifolius L. during maturation in field. The following four developmental phases during seed maturation could be recognized by critical analysis of temperature range for germination, and dry weight increment and moisture loss of seed.
The first phase covered stage flowering to about one half of dry weight of mature seed. At this phase, seed showed high moisture content, above 70%, and was not viable. The second phase was characterized by linear increase in dry seed weight, reaching a maximum weight of seed at the end of the phase. The moisture content was still at high level of above 60%. During this phase, germination occurred within comparatively wide temperature range. The third phase was characterized by rapid decrease of moisture content of seed. During this period, germination percent at higher temperatures declined, resulting in a restricted temperature range for germination. The last fourth phase covered the remaining period after the third phase. The seed gradually recovered the ability to germinate at relatively high temperatures.
