Laurel's partially rebuilt and completely reconditioned grass course will offer its first major showing today when 19 horses participate in the two divisions of the Turf Cup. Each section of the 1 1/2-mile feature offers $45,000 in purse money.

This race has been decided on the dirt since 1974 because the old turf course was deemed to be too soft to permit competition before the Washington, D.C. International. Laurel already has run one race on the grass at this meeting, however, with good results.

Bemo, carrying high weight of 120 pounds, heads the second division of the Turf Cup. The 7-year-old gelding captured the United Nation's handicap at Atlantic City last month. Bemo rarely finds himself in a position where he is asked to concede rivals from seven to 14 pounds as he will be today.

Gallapiat, 112 pounds; Festive Mood, 112, and Java Rajah, 108, all have a good chance of winning at the weights, as does Take The Pledge, 110, winner of this event last fall.

At least four of the runners entered in the Turf Cup will be scratched. Oilfield, Gallivantor, Antietam and Crackle ran in the $121,000 Nelson Handicap at the Meadowlands Saturday night. Oilfield, Gallivantor and Antietam are in the first division of the Turf Cup. Oilfield would have been favored. With him out, the strongest play in the pari-mutuel betting is likely to go to Grey Beret, the runner-up to Improviser in the Dixie Handicap at Pimlico last spring.

Green Beret is assigned 112 pounds. Resound, 112, and Double Quill, 115, appear to be his main rivals in an open contest.