There will be no rock music in Harvard Stadium this summer.

The "Summerthing" concert series-which last summer brought the Grateful Dead and Janis Joplin to Boston-will be forced to find a new concert site this year. No activities will be allowed on the Stadium turf next summer.

Edward S. Gruson, assistant to the President for Community Affairs, said yesterday, "The Stadium is not closed specifically to Summerthing. It is simply closed to all activities that would use the field itself. The main consideration is that the turf is in terrible shape since Harvard and the Patriots finished their seasons. It is a matter of necessity that the field be resodded."

Gruson denied rumors that incidents of purse-snatching and vandalism following the June 24 Ray Charles concert had anything to do with the decision.

The Stadium will not be closed to all activities. Those which do not use the field will be allowed to continue.

Summerthing, which was founded to provide cheap entertainment for Boston-area youth, is jointly funded by the City of Boston's Cultural Affairs Office and the Schaeffer Brewing Company. Last year was the first time that a complete concert series was held in the Stadium, although occasional concerts had been given during previous summers.

This year, for the first time, the freshman football team did not play in the Stadium. Harvard athletic officials said at the time that the move was made in order to allow the field to recover from the double duty of varsity and Patriot games.