The lettuce issue came to a head last night when members of the ad hoc student group supporting the United Farm Workers shut down the Dunster House dining room to one-fifth capacity.

The group decided last Friday to boycott a different House dining hall each night this week to show student support for its demand that Harvard purchase only union lettuce. Tonight the group will picket the Lowell House dining hall.

"We had a mandate on this issue," said David P. Levin '71, a member of the student group. "We went to the food purchasers last week with a petition signed by 1700 people, and we told them our reasons. But there is still scab lettuce at Harvard."

The picketers at Dunster House were not obstructionists and received a number of compliments on their tactic. It was a good thing to do," said one member of Dunster kitchen staff. "They were able to show their disapproval of something without messing anybody up."

Levin said that he was pleased that the boycott served an educational purpose as well, by permitting an extended question and answer period.

"We were able to reassure people on some points that were worrying them-like we explained to them that it's not a jurisdictional fight anymore." Levin said.

"The teamsters have publicly announced their support of the UFW. They want to get out of their contract with the lettuce growers, but it's to the growers' advantage to hold them to it. The teamsters probably won't be able to get out of the contract until the boycott is as complete as it was with grapes," Levin added.

Other students asked the picketers why they didn't get people to refuse to eat lettuce instead of getting them to boycott the whole dining room.

"We didn't want to boycott just lettuce because Harvard buys some union lettuce and we're not against that," said John H. Petrey '71, another member of the group. "We're boycotting the dining room to protest the buying of non-union lettuce, and we think we've been pretty effective at it."