What’s it mean when some leaves on one of your tomato plant’s leaves look like this?
Rest assured that most of our tomato plants do not look like the above picture, but a few leaves do have the yellowish tinge and dark spots about them. I’m pretty sure that means it’s the fungal disease known by the common name Early Blight. The manifestation of the Alternaria solani fungus, the plant disease is treatable through the application of fungicide or wholesale removal and destruction of the infected plant. I’ll opt for the former unless the fungicides turn out to be truly hideous chemicals.
Here is a page on the Wisconsin Dept. of Agriculture, Trade & Consumer Protection web site that discusses tomato blight.
Later: After some token research, I’m disinclined to use fungicides. I don’t want to eat the chemicals, thank you! Also, I was informed that Early Blight tends to strike if there’s been overwatering, or abundant moisture. We have certainly had an overabundance of rain the past few days, which would explain why the one plant is affected. It is indeed just a single plant. I’m grateful for that; I’d hate to have to remove a whole garden’s worth of tomato plants. Hopefully removing the infected leaves and disposing of them in the waste disposal will prevent the Blight’s spread.