Fig 1.
Asexual stages of the life cycle of Bremia lactucae.
Fig 2.
Diagram of the model simulating Bremia lactucae airborne conidia.
Table 1.
Description of variables and parameters used in the model.
Table 2.
Algebraic equations describing the movement of the stocks throughout the model.
Fig 3.
Examples of scatter plots of hourly-simulated versus hourly-observed airborne conidia concentrations of Bremia lactucae for the dynamic model developed to monitor airborne inoculum of the lettuce downy mildew pathogen.
(A) Example of a case when 0.90 < R2 < 0.96, and (B) example of case when 0.60 < R2 < 0.70. The dashed line indicates 1:1 agreement between simulated and observed airborne conidia. The solid line indicates the fitted values from the regression of simulated versus observed airborne conidia. R2, coefficient of determination. The inset graph in each panel represents the hourly-simulated and hourly-observed airborne conidia as a function of hour of day.
Fig 4.
Examples of scatter plots of hourly-simulated versus hourly-observed airborne conidia concentrations of Bremia lactucae for the dynamic model developed to monitor airborne inoculum of the lettuce downy mildew pathogen.
(A) Example of a case when 0.80 < R2 < 0.90, and (B) example of a case when 0.70 < R2 < 0.80. The dashed line indicates 1:1 agreement between simulated and observed airborne conidia. The solid line indicates the fitted values from the regression of simulated versus observed airborne conidia. R2, coefficient of determination. The inset graph in each panel represents the hourly-simulated and hourly-observed airborne conidia as a function of hour of day.
Table 3.
Coefficients of determination of the regression model of hourly-observed versus hourly-simulated airborne conidia concentrations of Bremia lactucae in a lettuce field.
n, number of simulations; R2, coefficient of determination.
Fig 5.
Regression analysis of daily-simulated versus daily-observed airborne conidia concentrations of Bremia lactucae in 1998, 2003, and 2004 for the dynamic model developed to monitor airborne inoculum of the lettuce downy mildew pathogen.
The solid lines indicate the fitted values from the regressions of simulated versus observed airborne conidia. R2, coefficient of determination.
Fig 6.
Daily-observed and daily-simulated airborne conidia of Bremia lactucae in 1997, 1998, 2003, and 2004 as function of day of the year (where day 1 is 1 January) for the dynamic model developed to monitor airborne inoculum of the lettuce downy mildew pathogen.
Table 4.
Evaluation of the regression model of daily-observed versus daily-simulated airborne conidia concentrations of Bremia lactucae in a lettuce field.
n, number of simulations; R2, coefficient of determination; Ubias, differences between the observed and simulated airborne conidia; Uslope, deviations from the 1:1 line; Uerror, the unexplained variance.
Fig 7.
Sensitivity analysis of the model to the sporulation rate.
The blue (1), red (2), and purple (3) lines represent the simulated airborne conidia for sporulation rates of 0.5, 0.6, and 0.7, respectively.