Knowledgebase

Black Spots on Tomato Plant Leaves #202996

Asked July 28, 2014, 4:26 PM EDT

I have a problem with several of my tomato plants. I have small black spots that started on the bottom leaves of the plants and has progressed through the top of the plants. Plants are loaded with tomatoes that are not ripening. I had a bit of potato aphids(think that's what they are,reddish brown in color)before the spots came. I'm wondering in the spots are more of a bacterial leaf spot or leaf mold caused by the humidity and cooler temps. at night. I've tried milk/baking soda spray as a fungicide but doesn't seem to help much. Many of my friends are having the same problem with their tomatoes. I have several varieties of tomatoes planted and they all pretty much got hit with this. The Super Fantastic and the Early Girl Bush got hit the worst and the Steakhouse and Big Boy Hybrid not as bad. I had another single plant of Super Fantastic that was planted about 25 feet from these along my fence and it doesn't seem affected at all. I'm just wondering if this is a lost cause at this point and if my raised beds are now contaminated for next year. Weird thing, is the plants still have a lot of green at the top and are blooming. I've attached a picture of the spotted leaves. Thanks in advance for the help.

Franklin County Pennsylvania

Expert Response

Hi:
Sorry for the delay. I have to admit that I am not a tomato expert. This could be septoria leaf spot (fungal) or possibly more likely, bacteria. Would you be able to send a sample to the Penn State Disease Clinic? They could give a specific identification of the pathogen.

http://plantpath.psu.edu/facilities/plant-disease-clinic

An Ask Extension Expert Replied August 05, 2014, 3:54 PM EDT

Loading ...