Not long ago, the NCAA basketball tournament was a ratings salvation for CBS. Of course, that was when NBC dominated Thursday nights with its “must see” lineup and when CBS was drawing the more modest audiences that watched “Promised Land” and “Diagnosis Murder.” Now there’s little chance that the basketball playoffs will draw as many viewers as Thursday’s regularly scheduled “Survivor” and “CSI.”

• “PoweR Girls” (9:30 p.m., MTV) chronicles the day-to-day dramas of notorious super-publicist Lizzie Grubman and her airhead minions.

Last week, we learned more than we needed to about Kelly, a 24-year-old with the mind of a toddler who has patterned her life — from her hair extensions to her diction — on that of Paris Hilton’s emaciated silhouette. When Kelly actually meets Miss Hilton she’s over the moon and even ditches her dull fiance to hang out in the heiress’s stretch limo. Sadly, she doesn’t have many inner resources to fall back on when she discovers that Paris has been playing her for a fool.

• Walter Cronkite introduces “Harvest of Shame” (8 p.m., Discovery Times), a groundbreaking 1960 CBS Report created and hosted by Edward R. Murrow that exposes the exploitation of America’s migrant workers.

Broadcast on Thanksgiving evening in 1960, “Harvest” would inspire a 1962 Migrant Health Act, mandating heath clinics and other improvements for farm labor.

“Harvest” remains a powerful film 45 years after its first airing. When was the last time any network aired a serious news documentary in primetime dedicated to something other than politics, gossip or a notorious trial?

Tonight’s other highlights

• Seth’s best-laid plans on “The O.C.” (7 p.m., Fox).
• Christina wants answers from Boyd on “Point Pleasant” (8 p.m., Fox).
• A test of commercial potential on “The Starlet” (8 p.m., WB).
• Pratt loses control of his vehicle and plunges into the deep on “ER” (9 p.m., NBC).