Salinas Valley growers feared a repeat of Delano. In 1970 Cesar Chavez and the United Farm Workers successfully won a contract with major grape grower Giumarra after violent clashes in the fields and a nationwide boycott. Before Chavez arrived in Salinas, ag companies preemptively signed with the Teamsters union – without any say from farmworkers. Chavez didn’t retreat. He organized campesinos in Salinas, triggering massive strikes and a prolonged lettuce boycott.

“We come to Salinas in peace because we are a movement that builds and not destroys,” Chavez told a rally, as shown in footage from the documentary, Vinegar in the Valley. The short film, which premieres Friday, June 5, at the National Steinbeck Center, recounts a volatile decade in Salinas with interviews from both sides of the bitter labor struggle.

“A lot of people know of Cesar Chavez very generally and know of the conflict very generally but it is so much more complicated,” says Colleen Bailey, executive producer of Vinegar. “I think it tries to get to really what happened.”

The genesis of the film dates back about seven years, when Joanne Taylor-Johnson, daughter of ag pioneer Bruce Church, asked the National Steinbeck Center to document the growers’ side of the lettuce strikes. The Steinbeck Center hired Dean Butler of Legacy Documentaries (he also played Alonzo on Little House on the Prairie), who produced nine interviews, including key players in the Bruce Church Company. (The company, led by Ted Taylor, was one of the last growers to sign with UFW in 1996, after nearly two decades of supermarket boycotts and multiple legal battles.)

Bailey, who is also director of community engagement and learning at the Steinbeck Center, revived the project by teaming up with five students at Dodge College of Film and Media Arts at Chapman University. The students captured the other side of the story, talking with UFW supporters, including union co-founder Dolores Huerta and Sabino Lopez, a former union organizer. Then they edited it together with Butler’s interviews and footage from the Steinbeck Center’s archives.

At a quick 22 minutes, the film can only provide an overview of the conflict. Still, Vinegar in the Valley exposes dramatic footage, opening with brutal beatings of farmworkers in the Coachella Valley. One black-and-white UFW ad shows a farmworker named Manuel with an amputated arm that allegedly became infected by pesticides while he was working for Bruce Church. Farmworkers describe the deplorable working conditions they wanted to improve, and growers explain why they didn’t want to forfeit control of their companies.

Director Zac Minor, who will be a senior at Chapman next year, says there isn’t a clear line between the good guys and bad guys in the labor dispute. “I hope that viewers walk away understanding the motivations of each of the parties involved,” he says.

With comments from journalist Miriam Pawel, the former Los Angeles Times reporter who wrote a controversial series in 2006 about UFW’s inability to organize workers and its straying from Chavez’s legacy, the film also touches on the current lack of unionization in the fields. Growers have changed their names and now largely hire workers through contractors.

“Once I got in bed with the union I couldn’t get out,” Bill Ramsey, owner of Mann Packing, says in the film. “I had to change my whole way of doing business and I almost went broke. But if I hadn’t done it, I would have went broke and Cesar wouldn’t have cared.”

The film closes with some victories from the UFW movement, from toilets in the fields to Latino elected officials representing Salinas. “I think that the movement and Cesar Chavez’s philosophy really kind of empowered a generation to really make change in their lives,” Minor says.

Vinegar in the Valley is still a work in progress. The filmmakers hope to gather feedback at Friday’s premiere before making final production decisions and submitting it to film festivals. The film will also feature a new score by local musician and Latin Grammy winner Orlando Castro.

Although the film presents both sides, Bailey still expects it to be contentious, with local growers already anxious over the election of union-friendly President Barack Obama. “We are not doing anything to ignite fear,” she says. “I think we should be learning from our history by looking at how things were done in the past. This is really a chance for healing and looking at things with a new lens.”

VINEGAR IN THE VALLEY premieres 6-8pm Friday, June 5, at the National Steinbeck Center, 1 Main St., Salinas. A panel discussion with the filmmakers and former LA Times reporter Miriam Pawel follows. Free. 775-4724.