Polyurea microencapsulate suspension: An efficient carrier for enhanced herbicidal activity of pretilachlor and reducing its side effects

• Published in: Journal of hazardous materials 2021-01, Vol.402, p.123744, Article 123744
• Main Authors: Chen, Hongjun, Liu, Xiu, Wang, Hongkun, Wu, Siyu, Li, Jingbo, Jin, Chenzhong, Xu, Hanhong
• Format: Article
• Language: English
• Subjects: Acetanilides; Herbicidal activity; Herbicides - analysis; Herbicides - toxicity; Interfacial polymerization; Polymers; Polyurea microcapsules suspension; Pretilachlor; Security
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2020.123744

[Display omitted] •Pretilachlor microcapsules suspension with controlled release function was prepared.•PMS had herbicidal activity against barnyard grass at dose of 270−540 g (a.i.)/hm2.•PMS exhibit insignificant side effects for rice at 270−540 g (a.i.)/hm2.•Co-treated with fenclorim ensure enough safety for rice at 270−1080 g (a.i.)/hm2. In this study, Pretilachlor polyurea microencapsulate suspension (PMS) with effective controlled release function was carefully prepared. Under the optimal conditions, wall material PM-200 dosage 4%, emulsifier T-60 dosage 4% with S-20 as solvent, the prepared PMS was demonstrated to have encapsulation efficiency approaching to 95.27 ± 0.57 % and high suspension rates of 97.33 ± 0.49 %. Afterwards, PMS was proved to possess average release rate reached to 85.56 %, 55.46 % and 15.85 % respectively in acidic, basic and natural medium. Subsequently, the herbicidal activity of PMS on barnyard grass and the growth safety of rice were evaluated. PMS showed enhanced herbicidal activity against barnyard grass and had lower toxicity to rice growth compared with technical pretilachlor at dose 270−540 g (a.i.)/hm2. In addition, the use safety of PMS was validated to be comparable to that of commercially available pretilachlor emulsifiable concentrate containing additive safener at dose 270−540 g (a.i.)/hm2. Moreover, inhibitory effect of PMS on rice growth was demonstrated to completely eliminated by cooperatively treatment with fenclorim. It was concluded that PMS had enhanced herbicidal activity and application safety, meeting the requirements of minimizing adverse effects of the herbicide on the environment, and enjoying a great application potential in agriculture.