**5. Final considerations**

For the improvement of the quality of the fruits it is important the use of soil analysis, foliar analysis and visual diagnosis. Those tools are extremely important because they enable the clear evaluation of the availability of potassium and further nutrients available for the plants. Those tools also help in the rational use of fertilizers because besides the producer refraining the waste with excessive fertilization, it does not apply some nutrient that could be limited in production, thus improving the economic results of cultivation with no damag‐ es to the environment.

Thereby the efficiency in the use of K is directly related to the direct effects on the amount and quality of fruits, being the handling of the fertilization one of the factors that strongly influences the sustainability in the production of fruit trees. In addition to the choice of K source, strategies should be sought for the handling of solo-plant systems that minimize the loss of this nutrient, taking the example of dose division, minimizing losses by lixiviation.
