Blightline July 17, 2014
No late blight has been reported in our region. Late blight severity values did not increase the past three days. If severity values in your area have accumulated to 15, application of a protectant fungicide such as mancozeb or chlorothalonil on a 7-10 day schedule is recommended. Many sites have reached this threshold.
P-day values, an indicator or early blight, are approaching 250-300 in many areas, and growers should consider application of an early blight fungicide and scout for the presence of early blight. Growers and scouts have reported that very little early blight is present now. The cool weather does not favor development of early blight.
Blightline July 17, 2014 (pdf)