The arrest Thursday on trespassing charges of Rev. Sun Myung Moon and 10 of his followers on the campus of Bard College was the climax of a long-simmering dispute between the college and Moon's Unification Church seminary a mile away, sources in the church and the college said today.

Moon and his group, who claimed that they were sightseeing at a picturesque waterfall near the campus at the time, were given summonses by state police upon a complaint filed by college officials.

However, Bard College President Leon Botstein said some of the Korean evangelist's followers were carrying walkie-talkies while they were on the campus grounds and were acting furtively. They have previously been warned not to attempt to recruit Bard students into the controversial religious sect, Botstein said. However, provisions had been made over the past three years for Moon disciples to speak in forums at the small, liberal arts college.

A Bard spokesman, George Hanold said, "Three years ago, and perhaps several times since, they have been 'uninvited' from the campus . . . We don't want the Unification Church on our campus. So far, they have not tried to force their way but we don't want that to happen."

Hanold said that the arrest of the Moon group, which was ordered by director of buildings and grounds Richard Griffiths, was a "purely precautionary" action designed to assure no future trespassing.

Daniel Holdgreiwe, a spokesman for the Unification Church of America headquarters in New York said that Moon's security people routinely carry walkie-talkies wherever the evangelist goes, and that "there was nothing sinister about this sightseeing trip at all." He said the party, which included Unification Church seminary students, did not notice any signs warning against trespassing.