Question
i live in southern middle tenn and my tomato plants have a problem. they developed rust colored spots on the leaves and have spread to adjacent plants. this began at the bottom and spread toward the tops of the plants.   the leaves wilt.  any idea of the problem?   so not see any insects.  

Answer
Kelly, your tomatoes have contracted one of several potential fungus diseases.  These would include verticillium wilt, fusarium wilt, or anthracose.

Unfortunately, once these diseases are in the soil, they quickly spread to the plants through spores in the soil from rain splashing or when you water.

You can try spraying the plants with any commercial copper-based fungicide.  These can be purchased at most garden centers and nurseries.  If the disease is at a later stage, these controls may not help.

Next year, you need to rotate your tomato plants to another area of the garden, or preferably to another bed.  Soil-borne diseases generally stay active in the soil for 2-3 years, so rotation is a must.

Another suggestion is to purchase disease resistant hybrids.  There are many on the market today that are not susceptible to most diseases.  These include Big Beef, Parks Whopper, Better Boy, and Celebrity.  You can search for more varieties on the Park Seed or Burpee websites.

http://www.burpee.com
http://www.parkseed.com

I hope this helps.  Good luck, and have a great holiday weekend.

Regards,

Mike