My tomato issues continue. This morning my Sweet 100 plant looked fine. About 12 hours later (6pm) today, most of the bottom leaves have yellow edges. Could this be sudden onset of early blight or a virus of some kind?

Its planted in an earthbox so I don't think it's a watering issue. I also used fresh from the bag potting soil.

It did get rather humid today. Could it just be environmental stress?

This is only my 2nd year growing so I'm not experienced enough to identify these issues.

Take a look at the photos and tell me what you think.

Also, do I prune off all affected leaves?