The pic with yellow leaves looks like early blight, normal on the lowest leaves that get shaded as the plant grows tall and ages. The white patches on the green leaves reminds me of a dusted plant after it rains, although 1 white spot looks webby (lower right), otherwise it's a new one on me. Best guesses.

powdery mildew

Agree it looks like mildew to me too. Remove severely affected leaves and spray with fungicide of choice. Several discussions about mildew running here right now so it is a common problems for many this year.

Dave

Thanks everyone. Any fungicide you can recommend?

The fungicide is your choice. There are probably 50 different brands so what is best is what you can get locally and quickly, like yesterday. Some list PM control specifically so read the labels.

For future reference it always pays to have a good fungicide already on hand.

Dave

It must be a local climate thing but in my 50 years of growing tomatoes here I've never had PM on my tomato plants. Squash, cukes, cantaloupe leaves for sure, but never tomatoes.