Mayor Marion Barry, responding to the discontent expressed by merchants, said yesterday he would investigate ways to improve the city's blighted Northeast Florida Avenue market area.

Barry talked to three merchants and bought a bag of pecans from a vendor as he walked through the area yesterday on a good will tour.

Sidney Kolker, owner of Washington Beef Co., largest in the Florida Avenue area, engaged in verbal jousting with the mayor, saying D.C.'s policy of giving 25 percent of city procurement to minorities has resulted in some minority businesspeople acting as brokers or jobbers by buying food outside of the District to sell to city agencies.

Barry, who said he didn't want to start on the wrong foot on the tour, quickly interrupted Kolker's complaint saying, "look, let's not go on off" with unfounded accusations.

Lawrence Schumake, director of the city's Office of Business and Economic Development, said later that he investigated Kolker's complaint and as of late yesterday found it to be untrue. Barry will get a full report next week, Schumake said.

The city is concerned about businesses in that area fleeing to nearby Maryland and commissioned a study to determine what Florida Avenue merchants need. The market, situated on 37 acres radiating from 5th Street and Florida Avenue NE, serves as a citywide and regional wholesale meat and produce distibution center where the area's restaurants and institutions buy food.

Automobiles, trucks, trash and stray dogs drawn by the aromas of fresh and decaying meats, fruits and vegetables crowd the market's streets.

Many of the buildings, erected in the 1920s, are largely unadorned, have broken and dirty windows and cracked sidewalks in front of them. Some workers huddled yesterday outside the buildings, warming their hands over fires in large trash barrels.

Besides food distributors, other retailers such as automobile repair companies, printers, banks, motels and restaurants have located in the area. There are two office buildings at the site.

The 46 wholesale food firms provide about 640 jobs, and all of the 80 businesses in the market provide about 1,000 jobs, officials said. Most of the firms employ fewer than 10 persons.

In D.C.'s business-retention study, Florida Avenue merchants said they need better security, improved truck loading facilities, wider and better kept streets, upgraded traffic signals and more parking space.

The area's advantages are its central location and good automobile and truck access to New York Avenue, the merchants said.

More than half of the employes of the 14 of 20 firms surveyed by the city were District residents. Sixteen of the firms queried have been in business there for more than 10 years, and seven firms said they wanted to expand their Florida Avenue facilities.