Gray leaf spot hits

Thanks to the efforts of the Turf Disease Working Group (an internet listserv community of turf diagnosticians), we have a fairly comprehensive look at the timing of this year's first gray leaf spot epidemics in the U.S. The table below summarizes the information we have so far received.

This information allows to see how well the Wong gray leaf spot index has been at predicting the appearance of this disease. (The index is calculated by adding together the high air…