The chairman of the Maryland Harness Racing Board said yesterday he expects his board to award 54 additional 1978 racing dates to the state's three tracks at a meeting on July 27.

Under the proposal, Laurel Raceway will extend its current meeting, scheduled to end Sept. 16, for 18 days. Then Rosecroft Raceway in Oxon Hill would reopen for 36 days, using its 18 dates plus 18 dates assigned to Ocean Downs.

"You can predict it," said Ben Schwartz, board chairman when asked the chances of the tracks getting the extra days made available in legislation signed by acting Gov. Blair Lee III last month.

The extra days would solve a possible horse shortage facing Laurel. Joe Shamy, track administrator, said that Liberty Bell Race Track near Philadelphia had warned horsemen now stabled at Laurel that they would not be granted stalls if they were not at Liberty Bell by Aug. 3.

"The horsemen kept begging for the extra dates," Schwartz said. "They don't want to leave. They want to race. One thing horsemen want to have is roots. Not having the extra days was the only reason they were going to ship to Liberty Bell. This is also a chance to get in more money for the state."

In 1977, with 201 harness racing dates, the state's share of the $68 million total handle was about $4 million. The 54 additional dates would increase state revenues by 27 percent, or more than $1 million.

Maryland is in the midst of its most successful harness racing season. Rosecroft closed its 1978 meeting with a record average handle of $497,000. For its first 16 nights, Laurel is averaging $474,946, a 9.9 percent increase over 1977.

Shamy said Laurel was undecided whether to use its additional dates in five-or six-day weeks, perhaps taking Mondays off because of televised pro football that night.

"Greta Shamy, (track president) doesn't want to fight the football season," said Joe Shamy. "But I feel you lose something when you don't have six nights of action. It hasn't been decided what we'll do.

"I'm tickled about the additional days," Shamy said. "Once they become offficial, our prospects of refinancing are enhanced."

Laurel is in litigation with Citizens Bank and Trust Co. of Riverdale over $2.5 million in loans obtained to buy control of the track. The management has been unable to obtain refinancing. It won three court cases this year, enabling it to open this meeting.