California's farmers are being racked by one of their periodic bouts of anxiety over the shortage of field hands. They want help urgently to replace low-cost labour being lost to the relative comforts and better pay of work in construction and retailing -- and the thousands of undocumented immigrants being kept out of the state by more stringent policing of the Mexican border.
Tom Nassif, the president of Western Growers, representing farmers and packers, said recently that the state's agricultural sector, with $31bn in annual revenues, faced imminent crisis.
Several farm operations in California and Arizona found themselves short of the minimum workforce needed to gather in bumper crops of fruit, nuts and vegetables, he said. "This problem has been building for some time. This year it's real."
His appeal coincided with reports of impending disaster from Californian raisin growers, who provide 100 per cent of the US crop, desperate to pick and dry this year's grapes before the rain.
This group made similar appeals in 1994, when it said there was a 20 per cent shortage, and again in 1998, when it claimed that only half the workers it needed were available.
The short-term answer, Mr Nassif said, was a temporary programme to allow workers in from south of the border to work through the autumn and winter harvesting and planting for the new season.
In the longer term Mr Nassif's organisation, in an uncommon alliance with unions and other growers' groups, supports a proposal in Congress to reform immigration law. The plan, known as "Agjobs" in its current manifestation, would allow immigrants willing to stay in agriculture for a set number of years to earn the right to permanent residency in the US.
Defining the scale of the problem is difficult because of farming's reliance on a largely undocumented workforce. According to the California Farm Bureau Federation, another leading lobby group, the industry usually needs about 450,000 seasonal workers at this time of year.
While it acknowledges that it has no official data, Western Growers says the state's main farming area in the Central Valley is having to cope without 80,000 of its normal complement.
One important factor in this year's crunch has been the deterrent effect of tighter border controls on undocumented migrants from Mexico -- many small farmers in search of cash before returning home for spring -- who formerly crossed relatively freely into the US.
By most estimates they account for between 70 and 80 per cent of those picking and planting in the state's peak season.
Nationwide, according to congressional reports, 55 per cent of farm workers are undocumented. According to Mr Nassif, the seasonal migrants have been "targeted" by Border Patrol agents, whose reports indicate the cross-border traffic has slowed. Official data from the main points at which the "illegals" usually enter California suggest declines of between 15 and 30 per cent.
But Mr Nassif also acknowledges the drain from the residential and retail construction industry. About 100,000 acres of farmland in the fertile Central Valley are being lost to home builders each year, giving the region the fastest rate of population growth in the state. According to the latest official data, the Californian construction industry added 63,000 jobs in August alone. Offering starting pay for labourers of about $10 an hour, while many casual hires on farms are paid the state minimum wage of $6.75 or even less, it has developed into a substantial competitor for the unskilled willing to work long hours in fearsome heat.
The farm-belt's mushrooming housing developments and associated services have also provided better-paid alternatives in gardening work or retail. Yet in the area around Fresno, the "raisin capital of the world", where the population has risen about 15 per cent in the past five years, some 30 per cent still live below the poverty line.