  TESS is finding transiting planet candidates around bright, nearby stars
across the entire sky. The large field-of-view, however, results in low spatial
resolution, therefore multiple stars contribute to almost every TESS light
curve. High-angular resolution imaging can detect the previously unknown
companions to planetary candidate hosts that dilute the transit depths, lead to
host star ambiguity, and in some cases are the source of false-positive transit
signals. We use speckle imaging on SOAR to search for companions to 542 TESS
planet candidate hosts in the Southern sky. We provide correction factors for
the 117 systems with resolved companions due to photometric contamination. The
contamination in TESS due to close binaries is similar to that found in surveys
of Kepler planet candidates. For the solar-type population, we find a deep
deficit of close binary systems with projected stellar separations less than
100 AU among planet candidate hosts (44 observed binaries compared to 124
expected based on field binary statistics). The close binary suppression among
TESS planet candidate hosts is similar to that seen for the more distant Kepler
population. We also find a large surplus of the TESS planet candidates in wide
binary systems, detected in both SOAR and Gaia DR2 (119 observed binaries
compared to 77 expected). These wide binaries host almost exclusively giant
planets, however, suggesting orbital migration, caused by perturbations from
the stellar companion, may lead to planet-planet scattering and suppress the
population of small planets in wide binaries. Both trends are also apparent in
the M-dwarf planet candidate hosts.
