Any ideas of what this is?

It is destroying my tomato plants

[Edited on June 3, 2013 at 8:29 PM. Reason : yo]

6/3/2013 8:23:28 PM

Is it a bottom leaf? If so. Pinch it off and throw it in the trash NOT your compost pile. If you're watering either use a soaker hose or try to water at the base. Tomato plants don't like to be watered above.

6/3/2013 8:48:19 PM

^did all that....I always water the base and try to water in the early morning to give time to dry

it's affecting a lot of leaves. I can prune them but I don't want it to come back

6/3/2013 8:51:04 PM

looks like bacterial spot, but you need to examine the lesions more closely to be sure, but looks likely, given the combination of chlorosis and spotting.
http://vegetablemdonline.ppath.cornell.edu/DiagnosticKeys/TomLeaf/TomLeafKey.html

you can use a copper spray to control bacterial spot, but it will only protect new growth. old leaves must be destroyed. Warm wet conditions and shitty practices in the greenhouse where it was grown/retailer are probably to blame.

6/4/2013 6:13:05 AM