Typically, this is more of a cosmetic issue than one that seriously harms the plant. Avoid any over head irrigation (or sprinklers that hit the foliage) and pick off and discard heavily infected leaves. Unless it gets much worse (and unlikely to if you follow the above recommendations), there is no need to resort to pesticides.

Thanks, appreciate the info! I never do the overhead watering, but I will get rid of the infected leaves.