I'm growing tomatoes in a raised bed. I planted four different varieties; one of them, Brandywine, has wilted pretty aggressively on one side of the plant (pictures below). I have a number of other tomatoes in the plot which look fine, but I'm concerned that if there's a disease it could spread to the other plants. I don't have much experience growing tomatoes so I would appreciate any help in identifying what the problem might be.
We water the tomatoes and peppers most days that it doesn’t rain. I planted them maybe a month ago, and fertilized once with Tomato-tone. I am located in hardness zone 7A.