Blight on my tomato leaves, or insect damage?

So it looks like my first time happy journey of growing tomatoes came to a halt. I found these spots on my tomato leaves and it look like some kind of bacterial or fungal infection that is eating the leaves away. I found this page with some good info but I couldn't match my problem with any of diseases shown: http://vegetablemdonline.ppath.cornell.edu/DiagnosticKeys/TomLeaf/TomLeafKey.html

Just for precaution I removed all the leaves with these spots, about 30% to 40% of leaves from each plants, but my guess is the bacteria are in the plants and they are done for. I sprayed the plants with baking soda, don't know if that will help any.

Fortunately, my black cherry tomatoes are resistant to this even thought they are next to the infected plants.

Please let me know if you know what type of disease it is, thanks.

This message was edited Feb 22, 2015 8:46 PM

looks like a leaf mold to me. have you tried applying copper?

Given that you are in Florida, it may be the very, very early signs of tomato blight, but I am not sure.

Can you contact your local master gardener?

I looked up copper fungicide, but it seems to be harmful for plants and microbes when overused. It seem sulfur fungicide is a less damaging alternative, so I'll give that a try first.

Sulfur fungicide is actually organic, although it must be used with car because it burns plants at a temperature over 80. It's my go to fungicide.

I have never used copper fungicide, because, yes, it seems harmful. Use the sulfur every few day. It is better as a preventative, but it's good stuff all round, and will restrict your damage and prevent new.

Copper is also organic as well as an important plant nutrient. It can be harmful to some bacteria and fungi which is what makes it an effective broad spectrum fungicide and bacteriacide. Sulfur is also toxic to several soil microbes and can reduce soil acidity as well. Products such as organic lime sulfur can also have human eye safety issues as well. The "overused" part is important. Any product should only be used as needed.

How did the Sulfur work out for you?

John

I stay away from copper and lime sulfur. I have never found it necessary to use them. I grow roses, and a lot of the hybrid tea growers seemed to feel it to be necessary to use lime and copper sulfur as preventatives. They didn't seem concerned about safety issues. I prefer to avoid them, and to avoid broad spectrum and compound products, preferring to diagnose and then treat with the simplest. The sulphur products I use are by Bonide and Safer, and I found them to be effective when used preventatively. I find that using a sharp spray of water, insecticidal soap, and elemental sulfur were effective and far less dangerous.

I just use a tea spoon per gallon of Safer brand sulfur and baking soda. It seems to stop or significantly slowed down that disease, my plants are doing much better.

There are still some plants that get a yellow spot in the lower leaves similar to an early onset of early blight, but it's not very bad, the leaves don't rot, just yellowing, so I trash those infected leaves. https://completegarden.files.wordpress.com/2008/08/tomato-blight-on-leaf.jpg

My black cherry tomatoes are impervious and doing very good. I will probably destroy all the other infected variety and grow beans in their place.

Glad to hear your tomatoes are improving. Sulfur alone hasn't been too effective for me as a natural pesticide up here in PA. But adding the baking soda does it! Serenade also works pretty good which is a biological product (Bacillus soil bacteria) and is much much safer than sulfur.

All of these products work preventively so any disease you already have will not be cured and it is best to remove those leaves and destroy.

Sometimes I do not apply anything or I apply something ineffective and what happens is the growing conditions change and are no longer favorable to the disease and I declare victory when it was the weather all along that changed!

It is very interesting how some varieties are not susceptible to the disease while others are!