Is this Septoria on my tomato & pepper plants?

Question

My wife and I have noticed the leaves on our tomato and pepper plants have been getting spots and yellowing and eventually falling off. On a couple of tomato plants, the main stem developed a black crack and appeared hollow inside and those plants completely died. We have hundreds of dollars invested in our container garden and are relying on the food. Is their any way to save our plants? Home Depot recommended Neem Oil.

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Answer 1

It is possible this is Septoria, but the image also matches other diseases common to Tomatoes. Use the links below to help make a diagnosis.

http://www.extension.umn.edu/garden/diagnose/plant/vegetable/summersquash/leavesdiscolored.html
https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-diseases.htm