POTASSIUM FERTIRRIGATION ON ICEBERG LETTUCE

The aim of this work was to evaluate the influence of potassium doses, being applied in fertigation on iceberg lettuce cultivar “Lucy Brown” in Typic Hapludox. The experimental design was in randomized blocks, consisting of six doses of K2O (0; 15, 30, 45, 60, 75 kg ha-1) and four blocks. The treatments were applied in six periods: 15, 21, 28, 34, 39, and 43 days after transplantation seedlings, using potassium chloride as a source of K2O. The variables analyzed were: total fresh mass, fresh head mass, head circumference, number of inner leaves, number of outer leaves, total number of leaves, total yield and commercial yield. Data were subjected to analysis of variance and means compared by regression models. Thus, we can conclude that the K2O doses that provides the highest value of the variables is 75 kg ha-1, with the exception of the number of internal leaves that do not have a significant effect.