Imperial Valley lettuce farmer Jack Vessey says it's the worst in his lifetime. Farther north in California's Central Valley, orange grower Manuel Cunha calls it the most constrained since before World War II. Coastal tomato grower Luwanna Holmstrom constantly worries about a repeat of two years ago, when she had to plow under $2.5 million in tomatoes left unpicked.

California and Arizona farmers - producers of half the nation's citrus and 90 percent of its vegetables and nuts - are struggling with an acute labor shortage. The situation, worsened by crackdowns on illegal immigration since 9/11, also extends to other states and is no longer just a matter of possible price increases on lettuce, oranges, or almonds, farmers say. Rather, it is a turning point in the nation's ability to produce its own food - and possibly the loss of major parts of its agriculture industry.

"We are trying to sound the alarm without being alarmist, but the situation has become extremely serious," says Tim Chelling of the Western Growers Association, whose members grow, pack, and ship half America's produce. "We are now talking of losing the production of key commodities to foreign competition. America's produce industry is facing a crisis."

Although the shortage was worsening before 9/11, it's now extreme, Mr. Chelling and the three California farmers say. Without an emergency guest-worker program, they will be dramatically short of the minimum number of workers needed to harvest the current crop. Without long-term immigration reform that acknowledges America's reliance on foreign workers, farmers will not be able to make ends meet, they say.

Mr. Cunha, for example, says Central Valley raisin growers need 50,500 pickers and have only 15,000. In the last harvest, $150 million to $300 million in grapes were ruined because they could not be picked and laid out to dry before the period of necessary seasonal sunlight passed. This year predictions are worse.

Mr. Vessey began harvesting romaine, iceberg, and red-leaf lettuce Tuesday. He was 200 workers short. "I lost $250,000 because of this problem last year," he says. "This year I am concerned I could go under completely. If I miss making my contracts with some of the big stores, they could look to China, Canada, Mexico, and elsewhere, and even if I recover my labor later, it may be too late."

Tightened border

Even before 9/11, other industries from construction to hotels, restaurants, and domestic services were luring workers away from the difficult and temporary work of harvesting. Increased border enforcement, which began a decade ago but has been ratcheted up since 2001, has further reduced the labor pool. In fact, by tripling the border patrol in recent years, the back-and-forth traffic of illegals has become so problematic that instead of returning to Mexico, many have moved farther into America's interior in search of full-time work - leaving seasonal agriculture work behind. This year, construction booms in the West and Midwest, hurricane reconstruction in Florida, and post- Katrina cleanup in the Gulf have siphoned off even more undocumented workers.

Higher wages would help, critics point out. "The problem is that the agricultural industry has come to expect that they will have exactly the workers they need when they need them and at the price they want them, but that is not the way the economy works," says Ira Mehlman of the Federation of American Immigration Reform.

Furthermore, America is not getting the cheap labor it expects from undocumented workers because of the unseen cost of $10.5 billion spent a year for health, education, and incarceration of such workers, he says. "If you started factoring in all the costs associated with these low-wage workers, you would realize the cost of a head of lettuce is prohibitive in this situation."

Farmers disagree.

"You always hear the argument that if we just paid decent wages and made these jobs open to legal Americans that the jobs would be filled," says Cunha, president of the Nisei Farmers League. "We have found that to be completely not so."

Vessey says he offered $8.50 an hour but that some workers choosing to harvest "per carton" can average up to $12 per hour. But when he went recently to Imperial County's welfare and economic development department seeking 300 workers for the next day, only one showed up to his fields and left after half a day.

Ripple effects

The loss of farm workers also has a ripple effect across agricultural regions, say economic analysts - with about 3.5 more jobs lost in packing, cleaning, transport, and other ancillary activities for every agricultural job not filled.

Vessey, Cunha, and Ms. Holmstrom all say they understand the concerns about security but claim that a new national dialogue about immigration reform is essential. They applaud President Bush's recent speech in Arizona, for acknowledging the need for a guest-worker program. They say it's critical because about 1.5 million of the nation's estimated 11.5 million illegals are known to work in agriculture. If that number dwindles, they say, no Americans will be there to fill the gap.

"If this doesn't change and change quickly, I think you could see the end of desert agriculture in this region," says Vessey. He supports a bill sponsored by Sens. Edward Kennedy (D) of Massachusetts and Larry Craig (R) of Idaho. Among its provisions: a plan to allow workers to earn the right to stay in the United States for up to six years and then apply for residency if they meet certain requirements.