Resposta de Cedrela fissilis Vell. à potássio e cloreto

Abstract

Knowing the nutritional demand of native forest species in the Amazon with timber potential is essential for the adequate supply of nutrients and increased productivity of these species. However, studies on the impact of the supply of potassium and chloride on the initial growth of wood species native to the Amazon are incipient. The study aimed to determine the critical level of K deficiency and toxicity for the initial cultivation and to investigate the effect of chloride on the development of young cedar plants. We conducted a study with five levels of K (0; 1; 2; 5 and 8 mM L-1), and another with four concentrations of Cl (0; 75; 750 and 7500 µM L-1) to investigate the state response nutritional, physiological parameters and initial growth of young cedar plants, grown in a greenhouse for 30 days. The K levels positively influence the initial development of cedar plants until the supply of 4.00 mM K L-1, however, below the concentration of 3.48 mM K L-1 in the nutrient solution, there was no significant response of the species. The critical level of K deficiency and toxicity in the aerial part dry matter in cedar plants was estimated at 26.08 and 27.28 g kg-1, respectively. In turn, the Cl concentrations did not significantly influence the physiological, biochemical parameters, content, accumulation and efficiency of use of this nutrient in the dry mass of the aerial part of the species, however, we recommend the supply of Cl in the initial phase for the good development of the cedar.