Tomato Disease Prevention-Ground Defense

While I love living in Charlotte, NC, come July my tomatoes do not.  Our hot and humid summers wreak havoc on them.  By the end of July/beginning of August they look like syphilitic lepers.  I have had to do major surgery to remove severely diseased limbs and the ones they still have don't look so hot.

Now, there are a number of effective chemical controls for the various fungal and bacterial diseases that set in here in the South.  Problem is, not all of them are organic.  Since I try to garden organically these options are off the table for me.

The good news is that there are some organically acceptable battle tactics that may ward off tomato diseases.  Some are hearsay (which does not mean they do not work).  Some have some science behind them.  This year I plan to regularly employ a number of them (yeah right, you know what they say about the best laid plans).  So here is my game plan...

These strategies are supposed to control soil borne fungal infections that infect tomato leaves.  This happens when pathogenic fungi get splashed on the plant's leaves by rain or overhead watering.  The fungi then set up shop and kick the plant's butt.

I already know not to water overhead.  However, there is this stuff called rain I can't do much about.  So here is my ground defense:

1. Mulch.  Cover the ground with a thick later of mulch.  When rainwater splashes back onto the plant, it has not come into contact with the soil, and does not carry pathogenic fungi.  I already do this to try to keep the weeds down.
2. Trim lower leaves.  The lower leaves on a midsize plant do not photosynthesize too much (they are on the bottom and don't get a lot of sun).  They do, however, get splashed by rainwater.  The plan is to remove all branches that are touching the ground (or very close to it).   If there is some splash from rain, it won't land on a leaf.  Just finished doing this one for the first time.  I do have to admit the plants look kind of funny with the bottom 8" or so bare.
3. Cornmeal.  There are some studies that suggest cornmeal feeds the good fungi in the soil.  The logic is that you feed and increase the good fungi, they will eat the bad fungi.  This leaves less of the baddies to infect your plant.  I am trying this one for the first time this year.

Okay, I'll be honest. I thought I was ahead of the curve this year.  But... I did not factor in that I also planted my tomatoes 6 weeks earlier than I usually do.  As a result, they already were showing signs of disease on some of the lower leaves (boohoo).  I am hoping the steps above, combined with my air defense (future post), will help keep things in check.

Do you have any other tips for controlling tomato diseases?