Development of a Preemergent Nanoherbicide: From Efficiency Evaluation to the Assessment of Environmental Fate and Risks to Soil Microorganisms

Author(s)

Takeshita, Vanessa ; Carvalho, Lucas Braganccommaa ; Galhardi, Juliana Aparecida ; Munhoz-Garcia, Gustavo Vinicios ; Pimpinato, Rodrigo Floriano ; Oliveira, Halley Caixeta ; Tornisielo, Valdemar Luiz ; Fraceto, Leonardo Fernandes

• Document type: Journal article
• Source: ACS NANOSCIENCE AU; v. 2, n. 4, p. 17-pg., 2022-08-17.

Abstract

Nanoparticles based on biodegradable polymers have been shown to be excellent herbicide carriers, improving weed control and protecting the active ingredient in the crop fields. Metribuzin is often found in natural waters, which raises environmental concerns. Nanoencapsulation of this herbicide could be an alternative to reduce its losses to the environment and improve gains in its efficiency. However, there is a paucity of information about the behavior of nanoformulations of herbicides in environmental matrices. In this study, the stability of nanoencapsulated metribuzin in polymeric nanoparticles (nanoMTZ) was verified over time, as well as its dissipation in different soils, followed by the effects on soil enzymatic activity. The physiological parameters and control effects of nanoMTZ on Ipomoea grandifolia plants were investigated. No differences were verified in the half-life of nanoencapsulated metribuzin compared to a commercial formulation of the herbicide. Moreover, no suppressive effects on soil enzymatic activities were observed. The retention of nanoMTZ in the tested soils was lower compared to its commercial analogue. However, the mobility of nanoencapsulated metribuzin was not greatly increased, reflecting a low risk of groundwater contamination. Weed control was effective even at the lowest dose of nanoMTZ (48 g a.i. ha(-1)), which was consistent with the higher efficiency of nanoMTZ compared to the conventional herbicide in inhibiting PSII activity and decreasing pigment levels. Overall, we verified that nanoMTZ presented a low environmental risk, with increased weed control. (AU)

• FAPESP's process: 17/21004-5 - Agriculture, micro/nanotechnology and environment: from evaluation of the mechanisms of action to studies of transport and toxicity
• Grantee: Leonardo Fernandes Fraceto
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 19/04758-1 - Nanoparticles as a carrier of herbicides applied in pre-emergency system in soils derived from no-tillage and conventional
• Grantee: Vanessa Takeshita
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/23608-8 - Development of labelled nanopesticides aiming studies of mechanism of action and toxicity
• Grantee: Lucas Bragança de Carvalho
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 20/12644-3 - Pre-emergent herbicides behavior in straw of different cover crops
• Grantee: Gustavo Vinícios Munhoz Garcia
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 17/15220-7 - Non-destructive image analysis methods for seed quality evaluation
• Grantee: Clíssia Barboza Mastrangelo
• Support Opportunities: Research Grants - Young Investigators Grants