ABSTRACT Providing nutrients in optimum quantities is essential for increasing the productivity of timber species. Despite this, we know little about the actual potassium (K) requirements of native Amazonian Forest species. This study aimed to determine the critical level of K deficiency and toxicity for the initial cultivation of cedar. We grew Cedrela fissilis seedlings in a nutrient solution under the effect of five concentrations of K (0, 1, 2, 5, and 8 mmol L-1) in a completely randomized design […]