I'm assuming this is wilt - help please.

[luke]

I've got wilt on two of my plants. Never had to deal with this.

I plan to pull both plants up - do I need to treat the soil, and does it need to be done now or later? I will go back with more plants in those spots after pulling them.

Thanks for any responses in advance.

Edit: Just noticed in the third photo the stalk looks slightly different than normal, almost a dust appearance.