Assessment of the early Growth of Amazonian Forest Tree Species under Exposure to Agricultural Pesticides

The increasing use of pesticides, driven by the global demand for food and energy, often results in environmental concentrations exceeding recommended levels due to indiscriminate use. This can lead to the decline of forest species such as Hymenolobium petraeum and Enterolobium schomburgkii. This study evaluated the impact of cypermethrin, atrazine, glyphosate, and 2,4-D at different concentrations on the initial growth of these species. The recommended doses used were: 0.02 l ha⁻¹ of cypermethrin, 4.5 l ha⁻¹ of atrazine, 3 l ha⁻¹ of glyphosate, and 1.5 l ha⁻¹ of 2,4-D. Based on these doses, the following concentrations were tested: ¼, ½, recommended, 2x, and 4x the recommended dose, along with controls with water and surfactant. After 30 days, Final Mortality (FM), Collar Diameter (CD), Stem Length (SL), Root Length (RL), and Dry Mass of Aerial Parts (DMAP), Root (DRM), and Total (TDM) were evaluated. H. petraeum exhibited higher sensitivity to cypermethrin and glyphosate, with severe effects observed even at ¼ of the recommended dose, particularly affecting dry mass. In contrast, E. schomburgkii showed greater sensitivity to atrazine and glyphosate, again with significant impacts on dry mass. Root dry mass emerged as an effective parameter for assessing pesticide toxicity in both species.