Resumen
Lettuce (Lactuca sativa L.) is the most commonly used bush plant in the world and for its cultivation the Nitrogen (N) is the most important nutrient. This study aimed to evaluate the fenometric variables lettuce response (Crisp American) depending on nitrogen fertilization. The experiment was carried out in a randomized complete block design with 6 replications and 5 Ammonium Sulfate (AS) doses: T1 = 0 ; T2 = 50; T3 = 100; T4 = 200 and T4 = 400 Kg ha-1. At the end of the experimental cycle, were evaluated only plant height (PH) due to leaf numbers and shoot fresh mass (FM) were not adapted to Regression equation. Regression analysis demonstrated that a higher mean value of Lactuca sativa L. growth by applying 360 kg.ha-1 showing the best crop height of 21,05 cm. High value of lettuce plant height to get 90 % of lettuce potential growth can be get by applying 200 Kg.ha-1 of Ammonium Sulfate, i.e, 40 kg.ha of N.