Kristhiano Chagas

Uso de leguminosas na fitorremediação de solo contaminado com sulfentrazone

Residual sulfentrazone may remain in the soil for around two years, being a source of groundwater contamination and preventing the growth of susceptible plants. So, phytoremediation may represent an option for decontaminating areas which were highly affected by applications of this herbicide. This study aimed at evaluating the potential of Crotalaria juncea , Canavalia ensiformis , Cajanus cajan and Cajanus cajan (dwarf) for remediation of soil contaminated with sulfentrazone, using millet ( Pennisetum glaucum ) as a bioindicator plant. The experiment was installed in a greenhouse and treatments consisted of the four species already mentioned, plus a control, and four sulfentrazone doses (0 g a.i. ha -1 , 200 g a.i. ha -1 , 400 g a.i. ha -1 and 800 g a.i. ha -1 ). Plants height, phytotoxicity to sulfentrazone and fresh and dry matter were evaluated. When P. glaucum was grown after C. juncea , the fresh and dry matter, as well as plant height, were higher, while the phytotoxicity symptoms were less evident. C. juncea showed the best results for phytoremediation of soils contaminated with sulfentrazone.

Enraizamento adventício de estacas do maracujazeiro silvestre Passiflora mucronata Lam.: forma de veiculação e concentrações do ácido indol-3-butírico

Adventitious rooting of wild passionflower Passiflora mucronata Lam. cuttings: vehiculation ways and concentrations of indole-3-butyric acid Passiflora mucronata Lam. is an ornamental, medicinal plant and resistant to bacterial blight on leaves. In addition, it is highly resistant to anthracnose in fruits and branches. The objective of this study was to evaluate the vehicultaion way, liquid or solid, and concentrations of indole-3-butyric acid (IBA) on adventitious rooting of P. mucronatacuttings. The experiment was carried out in a randomized block design in a 2x5factorial design (IBA vehiculation ways: liquid and solid x IBA concentrations: 0; 250; 500; 750 and 1000 mg L -1 for liquid or mg Kg -1 for solid), with four replicates with 16 cuttings each. The characteristics evaluated were rooting (%), root number, longest root length (cm), root volume (cm 3 ) and dry weight of root (g). It was found that the rooting of P. mucronata Lam. does not depend on the way IBA is conveyed, solid or liquid, but the quality of the root system, evaluated by means of the number , volume and dry mass of roots was superior to the one achieved whensolid IBA was used. The behavior of rooting, number and length of roots increased linearly up to the maximum concentration of IBA (1000 mg L -1 or mg Kg -1 ).

Risk of Soil Recontamination Due to Using Eleusine coracana and Panicum maximum Straw After Phytoremediation of Picloram

This study aimed to evaluate the herbicidal activity of picloram on the biomass of the remediation plants Eleusine coracana and Panicum maximum after cultivation in a soil contaminated with this herbicide. These species were grown in three soils, differentiated based on texture (clayish, middle, and sandy, with 460, 250, and 40 g kg–1 of the clay, respectively), previously contaminated with picloram (0, 80, and 160 g ha–1). After 90 days, the plants were harvested and an extract was produced by maceration of leaves and stems of these plants. It was applied to pots containing washed sand, comprising a bioassay in a growth chamber using soybean as a bioindicator for picloram. Soil and plant samples were analyzed by HPLC. The results showed the presence of picloram or metabolites with herbicidal activity in the shoots of E. coracana and P. maximum at phytotoxic levels with regard to soybean plants, indicating that they work only as phytoextractors and that the presence of straw on the soil surface can promote recontamination within the area. It is not recommended to cultivate species susceptible to picloram in areas where it was reported remediation by E. indica and P. maximum and still present residues of these species.