This information is updated from an earlier article by Janice LeBoeuf.
We have had multiple reports of late blight in conventionally managed tomato fields this week. Typically, this disease is well managed in tomatoes with a broadspectrum fungicide program including chlorothalonil. However, high disease pressure due to environmental conditions, combined with a dense leaf canopy and rapid growth may have resulted in poor spray coverage and reduced efficacy.
Commercial growers should scout often and ensure they are using fungicides with good late blight activity in their fungicide program. When late blight is in the area, spray intervals should be shortened.
Under continued high disease pressure, growers should consider adding a targeted late blight fungicide to the spray program. If late blight has been identified in a field, use a fungicide with curative and antisporulent activity, see the table below for late blight fungicides and their properties. Continue reading Late blight alert – July 27th, 2017
#1 
#2 
#3