The campaign against the use of toxic pesticides by California fruit growers must continue, said renowned leader of migrant workers Cesar Chavez in a speech last night at the Kennedy School.

Addressing a crowd of about 150 people, Chavez attacked growers and politicians for not banning the use of harmful chemicals in the grape and other fruit industries. These pesticides are the cause of birth defects, miscarriages, and cancer in workers, he said.

"The message is very clear," said Chavez, who organized a boycott on table grapes which was the first industry-wide agricultural boycott in U.S. history. "We demand that they stop spraying DDT, cancer-causing, and birth-defect causing pesticides."

He also criticized the Harvard administration for continuing to allow grapes to be served in student dining halls.

"This University should not be serving grapes," said Chavez in an interview with The Crimson after the speech. "It's a disgrace."

Chavez also suggested he might arrange a confrontation between farm workers and the University administration to force it to join the boycott on grapes.

Chavez who in 1962 organized the National Farm Workers Association--later the United Farm Workers of America (UFW)--has spent 41 years campaigning for better working conditons, higher wages, the end of child exploitation and a ban on deadly pesticides.

The Harvard Migrant Farm Worker Committee, a student group which raises money for migrant workers, sponsored last night's event along with a number of other student and community organizations.

Chavez began last night's presentation with a 15-minute UFW video demonstrating the devastating effects of pesticide exposure on farm workers and their children.

The video showed images of crying parents and their limbless and cancer-inflicted children beside scenes of politicians discussing "the balance of risks and benefits."

"The state government, county government and federal government are trying to trick the public," Chavez said. "Bureaucracy turns its back on us."

Although Chavez insisted on his commitment to non-violent methods, he said that relying on politicians is not the answer. "You can't do anything through public policy," he said.

Public action, on the other hand, works, he said. Citing the success of Martin Luther King Jr.'s bus strike as an example of effective activism, Chavez said, "We have to hurt the other side economically."

"Boycotts really work," Chavez said. "You cast a vote as many times as you want and the polls never close."