Quantifying indaziflam soil dissipation and thermal stability

Abstract Indaziflam is a long-term residual weed control option for Georgia pecan [ Carya illinoinensis (Wangenh.) K. Koch] growers. As a nonselective cellulose biosynthesis inhibitor, indaziflam has a niche for broad-spectrum weed control with long residual activity in various perennial cropping systems. Indaziflam’s soil persistence and chemical behavior at various temperatures have not been fully evaluated; therefore, the objectives of these experiments were to: (1) quantify indaziflam soil dissipation under field conditions in two common Georgia soils and (2) evaluate indaziflam molecular stability as affected by temperature and time using laboratory techniques. Indaziflam soil dissipation followed first-order kinetics and was adequately described by the exponential decay equation. Indaziflam half-life in Greenville sandy clay loam and Faceville loamy sand was 96 and 78 d, respectively. Indaziflam half-life and soil clay content had a direct relationship, while indaziflam half-life and microbial biomass had an inverse relationship. Aqueous solutions of indaziflam were exposed to temperatures that ranged from 20 to 70 C for up to 672 h, with results indicating that temperature had no influence on indaziflam’s molecular stability.