John I think we tend to blame ourselves too much. Recently the air has been incredibly humid esp 20th-23rd, with little sun, so leaves have enough moisture on them, collecting in low pockets, for blight spores to multiply. This morning I was surprised to find blight on even some Sungold tomatoes in the tunnel.
I agree that removing damage will limit its spread, and Vivian’s point about breaking leaves is good, though I sometimes cut.
The weather is drying up now so things will improve, also some cooler nights will slow the spread of blight.
