Aplicação foliar de selênio e calagem em mudas de Theobroma cacao L. para minimizar a toxicidade de cádmio

Abstract

The presence of cadmium can compromise the physiological and nutritional performance of plants and pose a food safety concern. Selenium application and liming have been investigated as alternatives to minimize the effects of cadmium toxicity. In this context, this study evaluated the physiological and nutritional effects of selenium application on cadmium toxicity and content in Theobroma cacao L. seedlings (genotype CCN51) grown in soil with and without liming. The experiment was conducted in a greenhouse at the Federal University of Lavras using a 2 × 3 factorial design, involving two cadmium levels and three selenium doses (0, 10, and 20 mg L⁻¹) under two soil conditions (with and without liming). Physiological parameters, antioxidant enzyme activity, nutrient, cadmium, and selenium contents in leaf tissues, and available soil cadmium were evaluated. Cadmium impairs the chlorophyll index and alters stomatal conductance and nutrient dynamics. Selenium application reduces cadmium availability in the soil, both in the absence and presence of liming. However, no significant differences in leaf cadmium content were observed in response to selenium doses. Thus, selenium application helped minimize the effects of cadmium toxicity in T. cacao seedlings (genotype CCN51) but did not reduce cadmium content in leaf tissues.