[en] The research was carried out with the purpose to study the effect of low dose of gamma rays Cobalt 60 on the callogenesis process in leaf and root tomato explants cv. Santa clara; the range of applied dose was 0 100 Gy with a rate dose of 28 Gy/min.At the same time an experiment with different concentrations of growth hormone 2.4 D (0; 0.5; 1.0; 1.5; 2.0 mg/l) to select the better treatmen for callow development was done. The results showed a differentiated response of hormones in the growth media and explant type. It was observed that the 5 Gy irradiation dose and the addition 2.0 mg/l of 2.4 D into the growth media cause significant changes in the development and the coloration of the callow; it was also verified that the root explant formed more and most qualify callow, than leaf explant

[en] Based in the obtained results by several authors and the experience accumulated by the group of Nuclear Techniques of the Agricultural Research Institute Jorge Dimitrov about the irradiation techniques; the methodology for tomato growth and productivity stimulation through the seeds irradiation was established. This methodology includes the preparation, irradiation and material selection to irradiate; as well as the sows of the material under field conditions. With her application the seedlings of good quality is guaranteed, what facilitates its transplant from the nursery to field conditions with 7 days in advance comparing to the control treatment, that contributes to the saving of material and human resources. Their fundamental contribution is given in the increment of the agricultural yield that reaches maximum values about 30% for some of the applied treatments. It is also recommended, the application of response- surface analysis among the plant yield (dependent variable) and the irradiation doses (independent variable) for determine the better stimulation doses in each one of the four varieties, as well as the time repeatability parameter of the growth and productivity were calculated, that which endorses the practical application of the proposed methodology