Question
Hi Mike,
I live in Atlanta and have noticed that right around the time my tomatoes are ready to be picked a number of brown spots (dime sized) begin to appear around the entire top of each tomato near the stem and quickly begin to rot. I thought it was due to them touching/bruising each other but have noticed that is not the case.

Any ideas?

Thanks,

Carl

Answer
Carl, it sounds like 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 please write again if I can ever be of assistance.

Regards,

Mike