Speckled Yellow Leaves on Tomato Plants

Question

Some of the bottom leaves look like they are dying. But the top, middle and new leaves have yellow speckles on them. What is causing this?

Answer 1

this should help:
https://www.gardeningknowhow.com/edible/vegetables/tomato/yellow-tomato-leaves.htm
And this too:
https://www.gardeningknowhow.com/edible/vegetables/tomato/early-blight-alternaria-tomato-leaf-spots-yellow-leaves.htm