LIVINGSTON, Calif. — They may have started as a few trees planted by Spanish missionaries, but almonds are now a big crop in California, where ideal climate and irrigation have let the nuts bloom into a $2 billion-a-year business.

On Scott Hunter's farm in the hot, fertile San Joaquin Valley, limbs on some of the younger trees are having a hard time holding up what he predicts will be part of "a once-in-a-lifetime type of crop" when the harvest begins in mid-August.

"Like any ag commodity, we've been faced with a lot of ups and downs," said Hunter, 37, who farms 1,200 acres of almonds in Livingston. "This year is definitely an up."

A record harvest, along with more growers dedicating acreage to almonds, is expected to solidify California's position as the world's leading producer of a crop that once grew wild in Mediterranean countries. The state already produces 80 percent of the almonds sold worldwide, according to California's food and agriculture department.

The U.S. Department of Agriculture expects growers will harvest more than 1.3 billion pounds this year, a nearly 17 percent jump from the 1.12 billion pounds harvested last year. Just a decade ago, the state's almond trees yielded 759 million pounds.

The predicted boom is due to a mix of auspicious conditions: a strong market, a spring bloom that went well despite a mysterious illness that killed bees used during pollination and favorable weather for the crop, which thrives in Central Valley soil from Bakersfield to Chico.