Influence of the conditions of storage on the seed quality of Stevia rebaudiana (Bertoni) Bertoni

Stevia rebaudiana (Bertoni) Bertoni is a native species of Northeast Paragu ay, which has been used for its sweetening properties for many years. In Co rdoba Province there is no research work related to different growing condi tions nor to seed storage. The aim of this paper was to determine the influence of two storage conditi ons over the germinative power, vigour and germinative energy of S. rebaudi ana. At the beginning of May 1996, the seeds were harvested in Bower, Santa Maria, in Cordoba Province, Argentina. Repetitions of one hundred seeds we re sown following a completely randomized design at the Seeds Analysis Labo ratory of the Faculty of Agricultural Science, University of Cordoba. These were stored for 11 months at 4 degrees C and at environmental temperature and moisture. The normal seedling number was recorded at six dates and, at the end of this study, the fresh and dry weights were obtained. The number of abnormal seedlings was also evaluated. For the six dates studied, there were highly significant differences betwee n the two ways of storage, as to the germinative power, showing that the co nservation in the refrigerator at 4 degrees C can be recommended for this s pecies. Differences were observed between the fresh and dry weight of the normal se edlings, showing that the storing condition in the refrigerator, produced h igher average values, at the same time presenting more vigorous seeds than those in the other treatment. Concerning the number of abnormal seedlings, significant differences were n ot found.