Ronald Reagan, completing a three-day swing through the South, charged today that George Bush has conducted a campaign of "bland generalities" and "knows very little about state government."

His attacks escalated the debate on the hot new issue in the Republican presidential race: who says less about "the issues."

Bush "made it through Iowa and into New Hampshire using only bland generalities," Reagan said in an interview. "I don't recall him ever being specific about anything."

Bush said pretty much the same thing about Reagan Friday, suggesting that the GOP front-runner and former California governor gave "simplistic answers to tough questions," "phony promises" and did not spell out specifics on how he would cut government spending if elected.

Asked about the charges at a news conference here, Reagan, who normally abides by the 11th commandment rule of not attacking fellow Republicans, said: a

"I think George Bush has been running on his resume, and I've been running on my record. And he has revealed he knows very little about state government."

Reagan, still exuberant from his 2-to-1 win over Bush in the New Hampshire primary, jokingly said that in recent days he hasn't been worried about his GOP rival disobeying that 11th commandment. In an obvious reference to Bush, he said, "Sometimes I worry about them breaking some of the other 10."

"Which one?" he asked.

"Thou shalt not bear false witness," Reagan said.

Meanwhile, Bush, campaigning in Massachusetts and Vermont, continued the direct criticism of Reagan that he began on Friday.

In a news conference in Westfield, Mass., Bush charged that Reagan had taken an "irresponsible, and, in fact, dangerous" position in arguing that the nuclear industry, not government, should determine the method of disposing of radioactive wastes.

During their debate in Columbia, S.C., Thursday, Reagan said, "I believe the best thing would be if the government had left the disposal of that nuclear waste in the hands of the private power companies, with the strictest of rules as to safety and the stiffest of penalties for the violation of those rules."

Bush said he believed government "must have the main responsibility," because "the danger of nuclear waste . . . is too great to leave totally in the hands of private companies, even under the most benign circumstances and with the best motives."

In campaigning in the two New England states that hold primaries next Tuesday, Bush banged away at what he called "flamboyant statements" made by his leading opponent.

He questioned the wisdom of Reagan's recommendation of a naval blockade of Cuba, his call for a freeze on the size of the federal budget, and he said, "As one who knows something of the petroleum industry," that Reagan's assertion that Alaska contains oil reserves as great as those of Saudi Arabia. "I don't believe it it possible."

Bush also questioned Reagan's claim that he had learned as much about intelligence matters by serving on a presidential commission investigating the CIA as Bush had in his job as CIA director. "He attended two of the 10 meetings of that commission," Bush said in Bennington, Vt. "I worked as director every day for a year."