The Boston School Committee, over- riding the objections of Mayor Kevin H. White, has requested that the National Guard be placed on standby alert to deal with the violent disruptions that have been spreading through the Boston schools since Monday.

In a telegram to Acting Governor Francis W. Sargent, chairman of the School Committee Thomas S. Eisenstadt asked that the Guard be available "in the event the current volatile situation in Boston goes beyond the capabilities of the Boston law enforcement officials."

Speaking for Mayor White, Police Commissioner Edmund L. McNamara said there was "no need" for the Guard. He announced an addition to the numbers of police personnel on duty "to keep the schools under surveillance and prevent vandalism. We have enough men on the street handling the situation."

The disturbances began this morning when about 300 students gathered at Boston English High School to demand the right to wear African dress in school. When the doors of English were locked at 10 a.m., the protestors moved on to Brighton High School, where the violence flared and became severe. Students ripped screening from windows, set grass fires around the school, and stopped passing cars, assaulting one cab driver.

At the same time, windows were broken, fire alarms were set off, and thefts occurred in at least seven other areas of the city.

Both Eisenstadt and Superintendent of Schools William H. Ohrenberger cited "outside influences" in the disturbances. Ohrenberger, in a prepared statement, called the violence an "obviously organized program of agitation" carried out by "irresponsible adults and misguided youths."

"These are not isolated incidents," Eisenstadt said. 'We will meet force with force. I would not hesitate for a moment in recommending expulsion for students engaging in this activity."