Actually many growers use the professional nursery to produce their seedlings. We have development a new concept of quality seedlings. It was used many different seedling quality parameters but it seems that homogeneity plants we have to consider a very important the factor for this question. We must know that is a good cultural management to become this objective. It is very usually in the commercial nursery to do a progressive and increase of the EC in the nutrient solution. In this experiment we work with the use of a gradual increase of nutrient solution EC. It were applied in four different treatments on the tomato seedlings and we can see as it was reduced the general seedling quality parameters in comparison with the application of complete and higher nutrient solution from the first days. But it was recorded a significant increase of the homogeneity of different seedlings in the nursery trays.