straw and blight?

[pacmanJohn]

I've used straw around the base of my tomato plants the last 3 years and it has worked well for weeds and keeping moisture under the straw, but I have also noticed that the last 3 years I've had a bad problems with blight which I had not had before. Could the soil under the straw be a breeding ground for fungus? I had heard that mulch helps with 'mud' splattering on the bottom of the plants during hard rain which would help against fungus/blight... confused...

Thanks for your input.