TOXIDADE DO FUNGICIDA COMERCIAL CONTENDO AZOXISTROBINA E BENZOVIDIFLUPIR EM MODELOS VEGETAIS

Abstract

Fungicides are pesticides frequently used in agriculture, due to their action to combat fungal diseases. The commercial mixture containing the fungicides azoxystrobin and benzovindiflupyr is applied to control the agent that causes soybean rust(Phakopsora pachyrhizi), which is capable of causing great economic losses. However, the use of this agrochemical can have negative effects on both human health and the environment. In order to verify the damage caused by these chemicals, the phytotoxic and cytogenotoxic potential of this fungicide in the vegetable models Lactuca sativa L. (Asteraceae) (lettuce) and Allium cepa L. (Amaryllidaceae) (onion) was evaluated through macroscopic analysis (germination and root growth), microscopic (mitotic index, chromosomal and nuclear changes) and enzymatic (specific activities of the enzymes catalase, ascorbate peroxidase and guaiacol peroxidase). It was possible to observe that there was inhibition in the growth of the roots, pointing out the phytotoxicity of this fungicide in the plant species tested in different concentrations. From the results obtained for cytogenetic analyzes it was possible to infer that azoxystrobin and benzovindiflupyr has the potential for cytotoxic and genotoxic, as it causes a decrease in the mitotic index, chromosomal and nuclear changes. In some cases, enzymatic activity was observed under different concentrations of the fungicide, which indicates the action of antioxidant metabolism. In both models, the ascorbate peroxidase response was the most sensitive to the treatments applied. The APX response of L. sativa was sensitive to the treatments applied, and when exposed to concentrations of 1,5 g L-1, 3,0 g L-1 e 6,0 g L-1 of azoxystrobin and benzovindiflupyr, there was a significant difference in activity when compared to the negative control.Finally, the results xiv obtained indicate phytotoxic potential due to changes in the activities of the enzymes ascorbate peroxidase, guaiacol peroxidase and catalase in the models studied.Such results indicate that this fungicide can be harmful to non-target organisms.