Warning that decisions made in junior high school can affect whether a student is likely to graduate from college, Virginia's secretary of education today called for political support for rigorous educational standards to end 15 years of "academic uncertainty" in the United States.

Appearing at the annual meeting of the National Governors Association, John T. Casteen III said high school students now tend to avoid rigorous mathematics and science courses and, without understanding the ramifications of such an approach, are thus determining what colleges, if any, will admit them and their eventual chances of graduating from college. .

Casteen was part of a panel discussion on education for a high technology society. The group addressed the growing technological challenge from Japan and other nations and said that the United States must improve the technological skills of its citizens to compete successfully in a world economy increasingly dominated by electronics and computers.

Other panelists warned of the growing division among those in the United States who are technologically proficient and those who are not. The number of high school students taking advanced placement tests in math and science doubled during the 1970s, for example, while overall test scores for students in those subjects were declining.

"The danger is a society of two cultures," said Edward E. David Jr., president of Exxon Research and Engineering Co.

Casteen said that students who complete the most rigorous curriculum in high school are as well prepared as any students in the world today and probably better equipped than their predecessors.

But that accounts for only about 8 percent of all students, he said, adding, "After that, it drops off rapidly."

Casteen, who previously served as dean of undergraduate admissions at the University of Virginia, said students who do not take introductory algebra in the eighth grade virtually preclude their admission to the better colleges in their region. About four-fifths of all students do not elect to take beginning algebra in the eighth grade, he said.

Those who fail to take introductory algebra by the end of the ninth grade have put themselves on a track that makes it less likely they will graduate from college, even if they enroll in an algebra course after high school, Casteen said.

He also said it is increasingly difficult to find teachers for math and science courses, in part because opportunities in private industry are more attractive.

Casteen blamed these problems in part on 15 years of "academic uncertainty about schooling," adding that during that period fads "replaced . . . academic rigor" and there was a rapid loss of academic unity in universities.

"We have seen the assertion . . . that math and science are opposed to the liberal arts," he said. "That is not correct. Math and science are central to the liberal arts. Only in the last 15 years have we come to the conclusion that students can choose to be competent in math and science or in English but not in both ."

Casteen called for political support for simpler standards of accreditation that focus on performance rather than "numbers of laboratories and doors." He said standards should be established that reward excellence rather than "inertia."

Basic education in this country is not the problem, Casteen said. "This is not an appeal to go back to basics," he said. "They aren't good enough." Instead he called for support for school curriculums in junior high school that help students build up their skills in increasingly complex areas.