As she came for luncheon with the Senate wives, First Lady Rosalynn Carter was asked whether she was doing any lobbying for the Panama Canal treaty.

"Yes," she replied before hurrying into the luncheon.

Since the annual Laddies of the Senate luncheon for the First Lady is always close to the press, it wasn't clear whether Carter had a chance for any last-minute lobbying before the vote on te treatly last night.Afterward one of the 105 guests said the talk was "light and enjoyable" without political overtones.

Joy Baker, wife of Sen. Howard Baker (R-Tenn.), was chairman of the annual luncheon yesterday and came up with a regional theme for the first time - "That's What I Like About the South."

It was carried out from the mossand ivy-covered trellises to the menu, which could be summed up as ham and biscuits with grits -although more elaborately listed with such description as "cheese grits casserole" and "brightened the Caucus Room of the Russell Senate Office Building, which had been the scene of theWatergate hearings.

Each of the guests received a cookbook as a place favor. For Carter, it was "Bayou Cuisine."

It took a bushel basket to carry out the books presented to the First Lady by the Senate club. They were authorautgraphed copies of books from each of the 11 original Confederate states and included works on history, fiction and travel.