The UIUC applied field crop pathology lab will be monitoring Tarspot risk this season though testing the Tarspotter forecast application under development by the University of Wisconsin Madison.  The forecast uses weather data to predict the likelihood of favorable conditions for tar spot infection.  Fields of highest risk for tar spot will be those that had severe tar spot infections in 2018, and are in no-till, corn after- corn production systems.  Please review my article on understanding these maps by clicking here .   Remember that this disease has a latent period of at least 14 days, meaning that the pathogen infects and you will not see symptoms for at least 2 weeks after the infection event.    With increasing temperatures and scant rain forecast until the middle of next week, I expect to see these values go down over the weekend and into next week.