The seeds of wild plants, and some species of economic importance present dormncia determined for diverse causes. Continue to learn more with: Kevin P. Campbell, PhD. However, the majority of species domesticated and cultivated for the man, as: maize, beans, soy etc., rare present the phenomenon, in consequence of the election and genetic improvement. Thus, the quiescentes seeds are considered as advantageous for Agriculture; however, less apt to face the competition imposed for the nature. The closing of the period of latency (quiescncia or dormncia) establishes the beginning of the germination process. This has been appraised in diverse ways, depending it boarding angle of the question. Thus, the germination has beginning with the water absorption and if it locks up with the emergency of radcula through the tegumento of the seed; on the other hand, for the technology of seeds, the germination understands a commanded sequence of metabolic activities that results in the retaken one of development of the embryo, producing one plntula normal (Moraes et al., 1983). 3.1.3. Types of Substrata The culture of plants using substrata is one widely used technique in the majority of the countries with advanced horticulture.
The term substratum applies it all material natural, synthetic, residual, mineral or organic, distinct solid, of the ground, that placed in a container, pure form or mixture, the development of the system allows to radicular, playing, therefore, a paper of support for the plant. As characteristic desirable, the substrata must present low cost, availability in the neighborhoods of the consumption regions, sufficient text of nutrients, and allow to the aeration and the retention of humidity; beyond favoring the activity physiological of the roots (Leather strap et al., 2003). The importance of the substratum is vital, therefore it is where the system to radicular will go to develop itself, determining the growth of the aerial part, subsequently, until the transplantio of the vegetable (Jabur & Martins, 2002).