The chief executive of the largest bank in the Maryland suburbs yesterday predicted that interest rates could rise to 30 percent in future years if inflation and other economic problems aren't brought under control.

Robert Tardio, chairman of Suburban Bancorporation, made the prediction at Suburban's annual stockholders' meeting, attended by more than 200 executives and stockholders.

"I believe that if we don't come to grips with the problems of inflation and other things like productivity in this country, the next time around interest rates could approximate 30 percent," Tardio said in a brief interview after the meeting.

Tardio said the interest rate cycles would show "great volatility" and that rates would continue to show "high peaks and very depressed valleys." This year the prime interest rate could fall to between 10 percent and 12 percent, he added.

Tardio predicted that interest rates would "fall precipitously" this year but that the borrowing rates then would "have a new (higher) base from which to climb in the future."

The bank executive also warned that without policy changes to encourage investment, savings and productivity, the national economy could go through a dramatic decline.

Tardio, known as one of the area's most outspoken banking executives, also warned that without strong steps to curb inflation the country could experience a "decline of the system as we know it and the intrusion of something similar to what happened in Britain after World War II."

"We can't long survive as the bulwark of the free world with a continuation of this trend," he said, adding that he was placing the blame on no one" in particular.

At the same time, Tardio's company, which operates 65 branch banks across Maryland, announced flat profits for the first quarter of 1980.

The company announced a slight drop in profits for the quarter, as income before securities transactions dropped to $3.97 million (84 cents a share), compared to $3.98 million (84 cents) for the first quarter of 1979.

Suburban was the second most profitable bank in Maryland last year, recording profits of about $16 million, up from about $13.3 million in 1978.

Tardio said that, in light of shrinking interest spreads and increased expenses, the first quarter report is a "very good performance." He refused, however, to predict whether Suburban's performance would improve in the second quarter.

Tardio said the "difficult period" faced by his bank and others would force significant changes in how the institution manages its services.

Noting that Suburban has 60,000 savings accounts of less than $100, he said the bank would institute a surcharge to make the small accounts profitable.

The bank, he said, would begin to "price each product to produce a profit" and offer the public "only the products they'd like to have and pay for."

During a question-and-answer session with stockholders, Tardio contended that Suburban is doing all it can to include women in the bank's management.

Judy Koenick, the questioner, at last year's meeting had raised the question of Suburban continuing to have an all-male board of directors. Tardio said Suburban in 1975 had women in 51 of 286 management positions. In 1980, the number of women in management had increased to 158 out of 433 such such jobs, he said.