The Prince George's County public school system has reached a critical period. We have a shrinking school system with a growing number of high-cost pupils. Demands are increasing for greater accountability, productivity and efficiency. There is a financial crisis as a result of TRIM, the limit on property tax revenues, decreased political support, diminished federal assistance and increased competition for money among county agencies.

If our evolving educational needs are to be met, Annapolis will have to play a greater role in the creation of a more equitable system of taxation, as well as in the allocation of educational aid, to accurately reflect regional student and demographic differences. It is ironic that TRIM, an effort to exert greater control over county fiscal policy, might lead instead to more state control of both our financing and educational systems.

Since the early 1970s, 53 schools and thousands of student desks have been emptied, more than 400 teachers have lost their jobs and class sizes have risen, resulting in as many as 40 students a class. The proportion of "high- cost" pupils--those requiring special programs such as vocational development, instruction for the learning-disabled and English for foreign students--also has risen. With changing family structures, the teacher's role has expanded to that of surrogate parent.

Major changes in the curriculum are taking place. New requirements in social studies and math and the inclusion of computer literacy courses will be costly but productive modifications. In addition, we are currently consolidating three administrative regions into two, converting our junior highs into middle schools and moving the ninth graders into high school.

The financial crisis facing Prince George's County can be traced to the passage of TRIM, which restricts property tax revenues to $139.6 million. Neither new construction nor inflation can increase this amount. The result has been decreasing county property tax rates that have culminated in a revenue shortfall affecting county services. And that 1979 limit of $139.6 million buys only $84 million of today's goods and services.

The county's fiscal troubles also have been exacerbated by both the federal and state governments. A 33 percent decline in federal financing for education since 1981 has further tightened our resources. The refusal of the state legislature to give Prince George's the power to increase income and sales taxes has further frustrated the search for more financing. The legislators in Annapolis have established a new lottery game, but this will only lighten some financial burdens temporarily.

So Prince George's, though severely limited by the state in the most lucrative revenue-raising projects, continues to scrounge for additional sources of money. There are crackdowns on delinquent taxpayers. Withdrawal of special tax treatment from the Capital Centre and increased revenues from video games also could produce some additional money. But results of these efforts are minuscule compared with the problems being tackled.

Other attempts to alleviate our financial problems don't look bright. Public support for education has fallen over the last decade: large increases in the numbers of singles, childless couples and elderly have weakened the political muscle of those with a direct interest in public schools.

Public schools themselves are trying to come up with other ways to raise money. Teachers and students are selling candy to help finance athletic programs and to buy needed educational materials. Admission- only athletic events are being held during the school day. Fees for summer school have been raised substantially, and user fees for many other programs are being considered. But all of this takes its toll on the disadvantaged student and on classroom instruction.

The state legislature's responsibilities in the area of school finance will have to increase dramatically if we are to have a productive and equitable school system. The state should consider new ways--less regressive than the locally used property tax--to finance education. The property tax falls especially hard on the poor, many of whom are renters.

Perhaps we should consider a form of statewide property tax in which businesses would pay a higher rate than homeowners, reducing the homeowners' financial burden. Additional increases in state motor vehicle fees and fuel taxes, institution of a sales tax on services, increased taxes on cigarettes and alcoholic beverages, energy taxes, value- added taxes and higher corporate income taxes all are possibilities.

The state also should consider a different formula for determining the educational aid dispersed to the different school districts. The education financial formula should be adjusted to reflect more accurately the number of high-cost pupils, cost-of-living differentials, and increased costs of urban areas.

If the roads to federal and local support have been blocked, then the only open route to a fair and equitable system of education finance leads to the state capitol