Fusarium oxysporum f. sp. lycopersici and Verticillium albo-atrum are two fungi that cause similar wilt diseases in tomato. Fusarium is more common in replant fields and gardens while Verticillium has been destructive on greenhouse tomatoes and in commerical stake tomatoes. Verticillium wilt is more of a problem at cooler temperatures while Fusarium wilt is considered a warm temperature disease. Both are favored by wet conditions.
Nesmith, William C. and Hartman, John, "Tomato Wilt Problems" (1982). Agriculture and Natural Resources Publications. Paper 40.