The field for Saturday's 34th running of the $400,000 Washington, D.C. International reached 14 today when the owners of Vanlandingham, Bob Back and Persian Tiara accepted invitations to race their horses in the Grade I classic. All will represent the United States.

Vanlandingham is a 4-year-old colt who has won two Grade I events and has earned more than $1 million in his career. He will be making his turf debut.

Bob Back is a 4-year-old colt and is the last horse to beat Pebbles, the Breeders' Turf Cup winner generally considered to be the world's best turf horse. That victory came in June at Ascot in England. This year, Bob Back won a Group 1 race in Italy but subsequently lost by a neck to Win in the prestigious Man o' War Stakes at Belmont Park. Bob Back is trained by Angel Penna.

Persian Tiara, a 5-year-old mare by Persian Gold, finished second in last year's International. Since then, she has won the Sheepshead Bay Handicap and La Prevoyante Stake and finished second in the Dixie Handicap at Pimlico.

One bettor collected $45,111.70 after the ninth race at Laurel yesterday when Lolapop (22 to 1), Prince K. And M. (105 to 1) and Don't Trick Me (9 to 1) ran one, two, three. The winner of the triple was paid in cash.

Maryland stewards held a hearing for suspended jockey Jamie Ryan and exercise rider Rene Maisonnueve on charges that they passed a battery (electrical prod) between them after the second race last Thursday. The stewards would not comment afterward.