Six candidates for Prince George's County executive aired their differences in public for the first time at a television taping session last night, with taxes and how to spend them the leading topics.

All six--four Democrats and two Republicans--favored raising the absolute limit on property taxes that the county can collect under the TRIM charter amendment, but disagreed on when that might be necessary and on whether the county's beleaguered school system should get more money as a result.

Budget constraints mandated by TRIM forced the school system to cut back on spending by about $30 million for the coming year and led to the layoff of more than 500 teachers.

Republican William Goodman, author of the 1978 charter amemdment, argued last night that the county can manage nicely under the TRIM provisions for another two years.

Both Goodman and Democratic candidate Kenneth W. Cutlip contended that the school system remains top-heavy with administrators and thus has room to cut costs without harming the quality of instruction.

County Council member Parris Glendening, considered the front-runner for the Democratic nomination and in the general election as well, spoke strongly in favor of the proposed "Plus 4" charter amendment--a modification of TRIM that the County Council recently approved for the November ballot.

"You can't have quality education unless you modify TRIM," Glendening said.

The Plus 4 amendment would allow the council to raise the TRIM-imposed $144 million the county can collect in property taxes with tax revenues from new developments plus an increase of an additional 4 percent on the new overall total.

Republican candidate Ann Shoch attacked the "Plus 4" amendment as being politically motivated, and argued that TRIM modification should not be considered until 1984, when no county offices are up for election.

Democrat John Lee Ball also argued against immediate passage of Plus 4, saying that with the current economic recession taxpayers are having trouble keeping up with mortgage payments. He suggested that county lawmakers "take the 4 percent increase and shelve it."

Arthur B. Haynes, a District of Columbia schoolteacher, stressed the need for improvements in the county's public transportation system, noting that "we have a county seat Upper Marlboro that citizens cannot get to by public transportation."

Haynes suggested lengthening Metro bus routes as a way of increasing ridership, while Goodman said he would consider using the county's yellow school buses to augment public transit.

The half-hour session will be aired Sunday on WJLA (Channel 7).