I have a few tomato plants where the tops of the leaves and stems are turning dark green/grey. Additionally, yellow circles are appearing on the leaves.
These were recently transplanted from indoor containers to a larger garden bed outside and didn't show these symptoms prior to living outside. That was about 1 week ago.
From what I've been able find while looking around this could be some form of blight? My plan was to prune the affected areas and spray with a baking soda solution, but I'm not sure if that would actually help since I'm uncertain what the issue is so far.
I have a few other tomato plants I've transplanted at the same time that don't show any of these symptoms that are in the same soil.
Update I've added a photo of a nearby tomato plant that isn't showing any of these symptoms and was transplanted at the same time. However, I did give this one some bone meal earlier than the others (before transplanting) because I saw the undersides of its leaves and the stem were turning purple. From what I've read that can indicate a phosphorus deficiency.
The bone meal fertilizer I used is 3-15-0.