EVALUACION DE LA TOXICIDAD DE DOS AGROQUIMICOS, ROUNDUP? ACTIVO Y COSMO-FLUX?411F, EN RENACUAJOS DE ANUROS COLOMBIANOS

Abstract

Roundup® Active is a herbicide based on glyphosate widely used in Colombia for control of illicit crops and weeds. However, it must be mixed with an adjuvant that facilitates its action, such as the Cosmo-Flux®411F, which improves the adhesion and fixation of the herbicide into the leaves of the plants. The aim of this study was to determine the median lethal concentration (LC50) and some sublethal effects (changes in body size and swimming performance) of the Roundup® Active and the Cosmo-Flux®411F to tadpoles of four Colombian anuran species exposed under laboratory and microcosm conditions. The most sensitive species to exposure of Roundup® Active was Hypsiboas crepitans (Laboratory: LC50 = 1414 µg a.e. glyphosate/L; microcosm: LC50 = 4 kg a.e. glyphosate/ha), and for Cosmo-Flux®411F was Rhinella humboldti (Laboratory: LC50 = 319 mg/L; microcosm: LC50 = 632.3 L/ha). In laboratory and microcosms, Roundup® Active did not alter the tadpole body size or swimming performance, while the Cosmo-Flux®411F generated changes in the body size, but not in the swimming performance. Comparing the LC50 of the two agrochemicals with respect to concentrations used in field, the Roundup® Active exerted a moderate risk whereas the Cosmo-Flux®411F was not lethal. In addition, the Roundup® Active was notably more toxic than the Cosmo-Flux®411F.