SANFORD, Fla. -- A judge ruled Tuesday to limit what attorneys can say in their opening statements in a trial over the fatal shooting of a black teen that raised questions across the U.S. about race and self-defence laws.

Attorneys won't be able to mention teen Trayvon Martin's drug use, suspension from school and past fighting in the opening of the trial of George Zimmerman.

Zimmerman is charged with second-degree murder in the 17-year-old's killing and has pleaded not guilty, saying he acted in self-defence after confronting Martin last year at a gated community in Florida

Circuit Judge Debra Nelson also rejected a defence request to delay the trial, set to begin June 10.

Zimmerman's attorney, Mark O'Mara, told the judge that Martin's marijuana use and past fighting was central to the argument that Zimmerman used self-defence.

"We have a lot of evidence that marijuana use had something to do with the event," O'Mara said. "It could have affected his behaviour."

An attorney for Martin's family, Benjamin Crump, said the teen's parents were pleased with the judge's rulings.

"Trayvon Martin is not on trial," Crump said.

O'Mara, said Nelson's decisions would not affect how he presented his case, but he acknowledged, that the defence would "have a lot more work to do than we can get accomplished between now and June 10."