Sensitivity analysis of leafspot progression parameters in the simulation model PEANUT

Simulation results of the leafspot disease progression subroutine in PEANUT are affected by the accuracy of the input parameters. This study was conducted to determine the sensitivity of the predicted percent infection to errors in the leafspot parameter values. Simulations were conducted by varying each of the 19 parameters by a predetermined amount while holding the other parameters at their reference values. The leafspot simulation model was most sensitive to parameter lp₈, the mean minimum time from spore contact on healthy leaf tissue until a sporulating lesion developed. Other parameters the model was highly sensitive to included lp₂, the fraction of ground covered by leaf tissue, lp₃, the fraction of spores which produce lesions after depositing on healthy leaf tissue, and lp₄, the conversion factor from spore trap data to spores/(lesion-day). Further investigation is needed to more accurately determine appropriate values for these parameters.