Norflurazon mobility, dissipation, activity, and persistence in a sandy soil as influenced by formulation

Area of Science:

• Agricultural Chemistry
• Environmental Science
• Soil Science

Background:

• Norflurazon is a herbicide used for weed control.
• Commercial formulations (CF) of norflurazon can exhibit mobility in soil, potentially leading to groundwater contamination.
• Ethylcellulose microencapsulated formulations (MEFs) offer a potential method to control herbicide release and persistence.

Purpose of the Study:

• To evaluate the mobility, dissipation, activity, and persistence of ethylcellulose (EC) microencapsulated formulations (MEFs) of norflurazon in soil.
• To compare the performance of MEFs with the commercial formulation (CF) of norflurazon.

Main Methods:

• Preparation of five ethylcellulose (EC) microencapsulated formulations (MEFs) of norflurazon.
• Application of MEFs and CF in soil columns to study mobility and distribution.
• Degradation and bioassay experiments to assess persistence and herbicidal activity.

Main Results:

• Norflurazon release into water from EC microspheres was retarded compared to CF.
• Norflurazon mobility in soil columns was significantly diminished with MEFs versus CF.
• MEFs showed higher norflurazon distribution in the upper soil layer (up to 50%) compared to CF (approx. 2%).
• MEFs exhibited greater persistence (t1/2 = 30.83 weeks) than CF (t1/2 = 7.72 weeks).
• MEFs demonstrated enhanced herbicidal activity compared to the commercial formulation.

Conclusions:

• EC microencapsulated formulations (MEFs) of norflurazon significantly reduce herbicide mobility in soil.
• MEFs enhance herbicide persistence and activity, allowing for longer weed control periods.
• The use of MEFs can minimize groundwater contamination risk and enable reduced herbicide application rates.