Role of sorption and degradation in the herbicidal function of isoxaflutole.
BACKGROUND
The fate of isoxaflutole (IFT) in soil is closely related to soil sorption. Sorption and transformation of IFT were investigated in laboratory incubations with four soils, and these results were used to interpret greenhouse studies using IFT to control several weed species.


RESULTS
Degradation proceeded by previously observed pathways to form diketonitrile (DKN) and benzoic acid (BA) derivatives, as well as traces of unidentified products. Over the course of the incubation, DKN was the dominant active form of the herbicide present in the experimental system, and was thus critical to the soil activity of the herbicide for weed control.


CONCLUSIONS
Control of most weed species appeared to be a function of both sorption and biodegradation of DKN, with greatest weed control being observed in soils in which a significant portion of the DKN that was formed persisted and remained bioavailable over the course of the incubation.
Sims
Gerald K
GK
United States Department of Agriculture-Agricultural Research Service, Urbana, IL 61801, USA. gksims@uiuc.edu
Taylor-Lovell
Sarah
S
Tarr
Gabe
G
Maskel
Shawn
S