A homeless schizophrenic is too crazy to be tried for the broad-daylight stabbing of an Upper East Side salon worker, says a court-ordered psychiatric report announced yesterday in Manhattan Supreme Court.

Curtis Forteau, 29, cannot understand the attempted- murder charges against him or assist in his defense, the report said.

He has been held since July 18, when he allegedly attacked Sabatha Tiradom, 24, daughter of a retired NYPD cop, on Second Avenue at 86th Street.