Use of a clay-based nanoformulation of R-imazaquin in an agricultural soil to reduce the pollution potential and improve the efficacy of this herbicide

Imazaquin is a chiral compound that can exist as two enantiomers: R-imazaquin and S-imazaquin. It is known that me herbicidal activity of imazaquin is due to the R-enantiomer mainly. This herbicide is characterized by a high mobility In alkaline soils, which may cause groundwater and surface water pollution. So, in order to avoid the addition of the less active S-enantiomer and reduce the great mobility of imazaquin, a clay-base-d nanoformulation of imazaquin containing exclusively the biologically active enantiomer was prepared. After evaluating several clay materials, cetyltrimethylammonium-saturated montmorillonite was selected as a carrier of the herbicide. due to its high loading capacity and great stability of the resulting nanoformulation. Next, the benefits of applying this nanoformulation compared to the use of the free (water dissolved) racemic herbicide or the free pure R-imazaquin enantiomer were assessed based on the leaching behavior and bioefficacy of the herbicide under a simulated intensive rain even to The results showed that the leaching of imazaquin was slower when the herbicide was added as nanoformulation in comparison with the free herbicide in the form of racemic mixture or pure R enantiomer. This was attributed to the sustained release of imazaquin from the nanoformulation, which reduced the amount of herbicide available for leaching. In a simulated scenario of a high water input shortly after herbicide application, the bioassay experiments showed that reduction of imazaquin losses as a consequence of the use of the nanoformulation led to a higher herbicidal efficacy than those for free racemic mixture and free R-imazaquinPeer Reviewe