The yellow patches are probably fungus. The evening showers we have had frequently over the late spring may have caused fungus to prosper. Growing the tomato in the same soil as used before may also spread the fungal spores. usually fungal problems start low on the plant and move upward. You can probably halt the problem by spraying the plant with a copper based fungicide. These products are organic as they are made from natural elements. You can also trim the affected leaves as they are not the areas that will produce fruits. You are obviously a careful gardener, so I think you will  to control the problem. if not, and it persists, take a sample of the damaged leaves to the Extension plant clinic, located at 569 Hanley Rd. (rte.238) about 3 miles northwest of Jacksonville. Please call<personal data hidden> for current days and hours of operation.

Thank you very much for the knowledge, advice and suggestions!

Liz

Does the sender of the question have further questions? i have answered the original question. see above for acknowledgment by Ms. Shen.

Yhou are most welcome. My own tomatoes are also spotting. Keep wwrinkled lelaves clipped off if you wish--helps control the spread.