Rotation is no solution to blight.
Blight is caused by an oomycete, (water mold) that travels airborne(most readily in damp humid conditions) from plant to plant, field to field and garden to garden and effects mostly potatoes and tomatoes. When one garden in a given area becomes infected it is a sure bet that every other farm and garden in the area will suffer unless immediate spraying begins and is kept up through harvest.
A few years back farmers and gardeners in this are suffered a huge costly outbreak that was attributed to seedlings sold at a local Walmart that were infected. So no, rotation will not cut it.
The only measure you can take against it it to spray fungicides as a prophylactic. I have found the only way to mitigate it is to spray with Daconil religiously every two weeks and especially additionally after each rain.
The map on this site shows how it spreads throughout the country(it will also give you a heads up if it is reported in your locality). Lots of good info on identifying it and combating it too.
https://usablight.org/?q=map
Every year it starts in the south, as a hard freeze kills it, and then travels north mostly along the eastern seaboard, but outbreaks in the Great Lakes area and the Northwest are not uncommon.
Thanks for the info, Guess i must be doing something else right then because I've never had it .
I'm very picky on where I buy plant starts, usually I do my own seed starts.