Sensitivity analysis of the core parameter b, rate of change in infection index with leaf wetness hour, was observed to be stabilized between 0.1 and 0.15 for both Pst and Pgt. Therefore, the use of b-value 0.117, which was reported for leaf rust [48], in the model for estimation of Pst and Pgt infection indices is justifiable for comparison of infection index values among locations. Here, SLCO2A1 is linked to infection.