Mayor Marion Barry and the Washington Board of Realtors proposed yesterday that as a means of fighting the city's rising crime rate, District residents leave their front and back porch lights burning all night for a week, beginning April 19.

"The police have told us that proper exterior lighting is one of the greatest deterents there is to burglary," Board of Realtors President James L. Eichberg said, flanked by the mayor at a District Building press conference. "Burglars prefer darkness."

Barry, who invited Eichberg to the press conference and gave his full backing to the porch-light program, praised the Board of Realtors for "joining in a meaningful way" his effort against crime.

Assistant President Chief Marty Tapscott attended the press conference to endorse the board's plan. But a police spokesman said later that most burglaries occur during the daylight hours.

"We know that more burglaries occur in the daytime," said spokesman Bill Jepson. "That's when people aren't home. Any burglar would know that it's a lesser crime to break in when people are not there."

The department's annual report for 1979, the latest year for which such figures are available, indicates that in the course of the year police received 10.591 calls reporting burglaries during the 8 a.m.-to-4 p.m. day shift and only 6,839 burglary calls during the midnight-to-8 a.m. shift. Another 11,-837 calls came in during the 4 p.m.-to-midnight shift, but the figures do not indicate how many of those calls came in before nightfall.

In addition, Jepson said, many of calls recorded on the evening shift were from residents who returned home after work to find that their home had been broken into at some time during the day.

Eichberg said the Board of Realtors planned today to mail to all its 2,000 members flyers headlined, "Turn On Your Lights and Turn Off Crime." The leaflets, gray with a drawing of a group of houses blazing with light, state that "a brighter neighborhood is a safer neighborhood," and asks home owners to turn on their front and back exterior lights and leave them on all week, beginning next Sunday.

"What will this do?" the leaflet asks rhetorically. "The police tell us that proper exterior lighting is one of the greatest deterrents to burglary. And in addition to that, it's a symbol. A symbol of community participation in an important endeavor on the part of you and your neighbors."

Eichberg said the borad is asking its members to distribute the leaflets to their customers and contacts.

The program "will demonstrate to our hard-working police that, in an age where noninvolvement seems to be the rule, the people of Washington want to get involved."

Eichberg said PEPCO officials have estimated that keeping the lights burning all night will cost 6 cents per light per night on the average home-owner's electric bill, or about 12 cents per night for a home with both a front and a back porch light.

"We would like to think that (District residents) will continue their lamp-lighting" after the week-long effort is over, Eichberg said. "We think it will work, it will be more than just symbolic."

In addition to the announcement of the porch light program, the board of realtors also took advantage of yesterday's press conference to publicize the 10-kilometer run the organization is sponsoring Saturday and to pass out to reporters a booklet containing the group's positions on a variety of issues. t