City sounds blended with country aromas yesterday at the farmer's market under the elevated Blue Line. The Metrorail trains were sometimes so loud you could hardly hear Maryor Marion Barry and U.S. Agriculture Secretary John Block bantering for the media folks covering the official visit.

"I don't usually do the shopping," said the agriculture secretary, explaining why his wife had preceded him to the open air afternoon market held Tuesday and Thursdays in a parking lot just north of RFK Stadium, at Benning Road and Oklahoma Avenue NE.

It operates with a small federal grant given to the University of the District of Columbia's Agricultural Extension Service, and the official presence was designed to highlight the joint effort.

As the mayor and the secretary waltzed down the aisle of vendors that ran a good city block, they paused to eat watermelon slices served up by Carl Sharperson, of Spotsylvania County, Va., and to ponder the produce from Washington County, Md.

Barry spotted plums for making jam but demurred when informed of their sour nature.

"I got enough problems already," the mayor said. "I don't need anything sour."

Block bought a $1 box of peaches, declaring them his favorite fruit "in any form."