ABSTRACT
This chapter deals with environmental influences upon flowering mechanisms, seed maturation, and germinability determined during seed maturation of annual weeds. During the process of seed development and maturation, the plant develops an independent organ containing an embryo, storage materials, protective tissue, and sometimes transport tissues. The influences of the red/far-red light may have some ecological implications on the germination of light-sensitive seeds under a leaf canopy. Portulaca oleracea seeds which matured under short-day germinate faster and to a higher percentage than seeds that matured under long-day. In Amaranthus retroflexus, seed germination is affected by the light intensity under which the mother plant develops and matures. In Datura ferox, a summer weed, a low-light intensity as well as water stress during seed maturation increased the germination percentages and decreased the level of seed germination inhibitors. The seeds accumulate and disperse in the soil depths through soil cracks, by soil movement, and plowing.
