However, for the technologists of seeds, the germination is recognized as such, since that plntulas presents enough size so that if it can evaluate the normality of its parts and its possibility of survival. Therefore, of the physiological point of view, to germinate is simply to leave the rest and to enter in metabolic activity. For Son et al. (1986) the germination is a sequence of physiological events influenced by some intrinsic and extrinsic factors to the seeds. Each factor can act for itself or in interaction with excessively. It is affected for a series of intrinsic conditions and ambient factors, whose set is essential so that the process if develops normally. The external factors or extrinsic essentials are: the humidity, the temperature, the light, the oxygen and the water.
The light has not been enclosed as an essential factor because, being about an agent of ' ' quebra' ' of the dormncia, since that this phenomenon is surpassed, the germination will be able to occur in such a way in the presence as in the light absence. According to Ministry of Agricultura and the Agrarian Reformation (1992), the humidity is an essential factor, therefore it is with the water absorption for embebio that if initiates the process of the germination. So that this happens, it has necessity of that the seed reach an adequate level of hidratao, that allows the reactivation of the metabolic processes. The adequate humidity is changeable between the species. In function of its relation with the speed of the chemical reactions, it is considered that the temperature addition, inside of excellent limits, contributes to speed up the germination process. It must have, therefore, temperatures where the efficiency is total, as well as extremities (maximum and minimum) for its accomplishment; the extreme limits, that is, the maximum temperature and the minim, as well as the excellent considered ones represent the ideal temperatures for the germination (Son et al., 1987).