*2.7. Dissipation Constant and Half-Life for Fluopyram in Soil and Scallions*

The dissipation constants for fluopyram in soil and scallion were calculated using a first-order kinetic model using Equation (1) [7,17,18]:

$$\mathbf{C}\_{t} = \mathbf{C}\_{0} \times \mathbf{e}^{-\lambda t},\tag{1}$$

where *Ct* is the concentration of fluopyram in soil or scallions at time *t* (day), *C*<sup>0</sup> is the initial concentration of fluopyram in soil or scallion at DAP 0, and *λ* is the dissipation constant. The half-life (DT50) of fluopyram was then calculated using Equation (2) [7,18]:

$$\text{DT}\_{50} = \ln \text{(2)} / \lambda = 0.693 / \lambda\_\prime \tag{2}$$

The time-dependent residues of fluopyram in soil and scallions were evaluated using the F-test, regression equation, and regression coefficient (R2). The mean and 95% confidence interval (95% CI) of the dissipation constant (*λ*) were calculated using regression analysis. Statistical analyses were performed using the statistical program, SPSS 18.0 (SPSS Inc., Arming, NY, USA).
