High Schools’ Best Efforts to Be Staged : Drama: Winners of the Southern California Educational Theatre Assn.’s 19th annual festival will be showcased.

Peter Shaffer’s psychological drama “Equus” and Bill Johnson’s melodramatic study “Dirty Work at the Crossroads” are among the best of Southland high school productions featured today through Sunday at Plummer Auditorium.

The two plays, along with Jim Leonard Jr.’s “And They Dance Real Slow in Jackson,” are the winners of the Southern California Educational Theatre Assn.’s 19th annual festival.

Leonard’s work, directed by Walt Stuart for La Jolla High, will be offered tonight at 8 p.m. “Dirty Work at the Crossroads,” directed by Darrell Mathews for Whittier’s California High, is scheduled for 7:30 p.m. Saturday. And “Equus,” directed by Phil Holmer for Arlington High in Riverside, will be staged at 1 p.m. Sunday.

Festival spokeswoman Maxine Lewis said the productions were chosen from 59 entries from high schools throughout Orange and San Diego counties and the greater Los Angeles area. Although no Orange County high school won one of the big prizes, Dana Hills High School in Dana Point and Mission Viejo High School will be represented in smaller programs.

Ten-minute scenes from Dana Hills’ “The Skin of Our Teeth” (directed by Robb Rigg) and Mission Viejo’s “The Crucible” (directed by Anne Vardanian) are scheduled for Friday morning. The performances will be open only to students in the festival, Lewis said.

Scenes from “Cat’s Paw,” “The House of Blue Leaves” and “The Skin of Our Teeth,” among others, will be offered on Saturday and Sunday, but also only to participants.

Lewis pointed to the diversity of this year’s festival as a sign that high school drama programs are flourishing. She was impressed that many of the notable productions are dramas with adult themes.

“This indicates that we’re ready to tackle and pull off the serious stuff,” she said, “as long as the teachers and directors are willing to work closely with the students. It’s appropriate that something powerful like ‘The Crucible’ is done at high schools (because through the staging) the kids learn about so many things, especially when the directors are good teachers.”

Darrell Mathews, a drama teacher at Whittier’s California High and the director of “Dirty Work at the Crossroads,” emphasized how much work goes into each production. The students at California High, which won a major prize for the second year in a row, spent months rehearsing their program.

“They approach it like the sports teams approach what they do, with much dedication,” he said. “The results are that they learn poise, self-confidence and some dramatic skills during the process.”

As for the festival’s overall quality, Lewis--who has judged college drama competitions--said the best of the high school productions compare favorably to good university stagings: “I would feel free to recommend any of these to anybody.”

The Southern California Educational Theatre Assn . presents high school festival today through Sunday at Plummer Auditorium, 201 E. Chapman Ave., Fullerton. Tickets for showcased plays are $4. Information: (714) 870-3735 or (714) 876-4277.