Abstract:
En
|
Text:
En
|
PDF:
En
Abstract Background Phytoremediation is a technique used in soils contaminated with residual herbicides, such as tebuthiuron. However, the herbicide presence in the soil and plant matrices are not generally quantified. Objective This study aimed to select plant species to evaluate the phytoremediation of 14C-tebuthiuron by showy rattlepod (Crotalaria spectabilis), sorghum (Sorghum bicolor), radish (Raphanus sativus), peanut (Arachis hypogaea), and alfalfa (Medicago sativa) in herbicide-contaminated soil. Methods The selection of the five herbicide phytoremediation plants was with the application of five rates of tebuthiuron (300, 600, 1,200, 2,400, and 4,800 g a.i. ha-1) and compared to a control. Peanuts and sorghum (herbicide-tolerant plants) were sown in soil contaminated with tebuthiuron (600 g a.i. ha-1) applied through a working solution containing 17.47 kBq of 14C-tebuthiuron. The total of herbicide was analyzed in the soil and plant at three phenological stages. Results Showy rattlepod, radish, and alfalfa were sensitive to the herbicide even at the lowest application rate. Sorghum was tolerant to the herbicide up to 600 g ha-1 with the application of 1,200 g ha-1, there was 80% injury; peanut was tolerant even at the highest rate (4,800 g ha-1) with only 40% injury. Peanut and sorghum were able to phytoremediate the soil, although, peanut was more efficient in decreasing tebuthiuron contamination by 76%, while sorghum reduced at by 45% at 3rd phenological stage. Conclusions Thus, both plants can be recommended in succession/rotation with crops that had tebuthiuron applied from pre-emergence weed control. herbicides However quantified 14Ctebuthiuron Ctebuthiuron 14C C Crotalaria spectabilis, spectabilis , spectabilis) bicolor, bicolor bicolor) Raphanus sativus, sativus sativus) Arachis hypogaea, hypogaea hypogaea) Medicago sativa herbicidecontaminated 300, 300 (300 1200 1 200 2400 2 400 2,400 4800 4 800 4,80 ai i a.i ha1 ha control herbicidetolerant (60 1747 17 47 17.4 14Ctebuthiuron. stages 60 ha- 1,20 ha1, 1, 80 injury (4,80 40 although 76 76% 45 rd stage Thus successionrotation succession rotation preemergence pre emergence 30 (30 120 20 240 2,40 480 4,8 (6 174 17. 6 1,2 8 (4,8 7 3 (3 12 24 2,4 48 4, ( (4, 2, (4