Farm laborers will continue to be paid overtime after working 10 hours in a day or a 60-hour week under an exemption that dates to 1941.

California already is "the most progressive state in the nation" because it provides limited overtime for agriculture workers, Schwarzenegger said in his veto message.

He noted federal law exempts farmworkers from any overtime pay. The California Farm Bureau Federation says only Maryland and Minnesota require farmers to pay workers overtime if they exceed a weekly limit.

The Legislature, Schwarzenegger said, has long held that "agricultural work is different from other industries: It is seasonal, subject to the unpredictability of Mother Nature, and requires the harvesting of perishable goods."

He said increasing overtime would harm agribusinesses and make California's largest industry less competitive with other states. The industry employs as many as 450,000 workers in the peak harvest months of August and September.

State Sen. Dean Florez, D-Shafter, who authored SB1121, said the Republican governor missed a chance to reverse a practice that treats farmworkers as a lower class.

"They want to be treated with dignity the same as other workers around the state. He decided to keep the caste system in place," said Florez, whose father and grandparents worked the fields.

United Farm Workers President Arturo S. Rodriguez said in a statement that the veto continues a "shameful legacy of racism" that targeted field hands who once were mostly black but now are mainly Hispanic.

Florez criticized the timing of the veto, on the same day as Arizona's controversial immigration law was to take effect. A federal judge delayed key provisions in the Arizona law at the last minute.

"It's kind of a double whammy for a lot of employed immigrants," Florez said of the actions in California and Arizona. "Two governors, with the stroke of their pens, have kind of taken us back to the segregationist South. It's a shameful kind of veto."

Schwarzenegger spokesman Aaron McLear called the criticism "hypocritical" because Florez previously voted to exempt farm workers from the standard overtime requirement. Schwarzenegger, in his veto message, noted he approved an increase in the state's minimum wage and enacted the nation's first regulations to protect field hands during hot weather.