Scattered around the Californian state capital Sacramento are photo­graphs of governor Arnold Schwarzenegger - not in typical electoral pose, but sitting astride a Harley Davidson, leather clad and complete with dark sunglasses.

For some Californians, therefore, it may be hard to take their governor - affectionately known as 'the governator' - too seriously.

Yet when it comes to food, Schwarzenegger is deadly serious. He is a proponent of the 'Buy Californian Grown' campaign and is pushing the message globally.

Given the size of California's food and drink industry, it's easy to see why food is such a serious issue. In 2004, the state's gross income from agricultural production sat at $28.5bn. It is the world's fifth largest supplier of food and agricultural commodities and, on a national scale, is the US's sole producer of almonds, raisins, prunes, olives, walnuts and pomegranates. The UK market is also important:the EU is its biggest export market, worth some $1.7bn, mostly from almonds, wine and walnuts.

Despite such promising figures, times are hard for many in the industry. Two years of poor weather has hit many crops hard, with late spring rains causing serious planting delays for two major crops in particular - rice and tomatoes.

Rice seeds are normally planted in early April, but growers had to wait weeks for the fields to be dry enough to plough. Tomato growers were having an even harder time this spring, with farmers about five weeks behind schedule in transplanting seedlings into the fields because of standing water.

According to growers, the resultant late-maturing crop will be vulnerable to damage from early rainfall and will also cause too many tomatoes to ripen at the same time, straining the state's processing capabilities.

The cherry industry, which supplies Bing cherries to the UK market in May and June, has also been hit. Jim Culbertson, manager at the California Cherry Advisory Board, says: "This year's California cherry crop is expected to be about three weeks later than normal. The early cherries from the southern growing areas will be a little lighter in volume, but it is expected that the later Bing crop will be much the same as last year's volumes."

Two previous years of drought have also impacted on the prune industry, according to Richard ­Peterson, executive director at the California Dried Plum Board. He says the dry weather has led to a 50% cut in exports over the past two years, and admits that decent weather this year will be vital for the long-term future of one of California's biggest industries. Indeed, an oversupply of 80,000 tonnes from previous years has enabled the industry to keep supplies at a manageable level.

Tightening controls on illegal immigration is another issue keeping growers awake at night. Reform is under way that would make it a federal offence to live ­illegally in the US. Yet California's industry depends on millions of migrant workers, many of whom are in the country illegally.

There are 12 million illegal immi­grants in the US, about 5% of the workforce. California and Texas are home to more than a third of them. Strikes have already taken place around California, where 14 million of the 33 million population are Hispanic. Tyson Foods, the world's largest meat processor, shut five of its nine beef plants across the US, and Gallo Wines in Sonoma gave 150 mostly Hispanic employees the day off.

Prune and peach farmer Philip Filter says any moves to cut the number of migrant workers would be devastating. Peach farmers, in particular, would be hit hard because of the labour-intensive methods of harvesting, he says.

"Peaches used to be harvested mechanically, but the damage caused by the machinery means that canners don't allow it any more. Canners deduct money from people who use them."

It is also an issue for the table grapes industry, which uses hand-picking. Susan Day, vice president of international marketing at the California Table Grape Commission, says: "It's a big issue. There have been problems ­because we've had such large crops. In large crop years you need more people and it's an issue to find crews."

Grower Neil Mitchell says ­demands on growers to ensure they don't use illegal immigrants is also a problem. At present job-seekers can provide about 12 easy-to-forge documents, and he says farmers haven't the time or money to check them. "The ­authorities want us to verify the documents, but it costs money to go through a clearing house and it could take days that we can't ­afford to lose. We have to put crews to work at our own risk."

California is also in the grip of rising fuel prices, which hit record highs this spring. Says Filter: "Costs of fuel, labour and insecti­cides have increased, but prune prices haven't reflected this."

The threat of avian flu is also an issue. State officials say that migratory bird routes stretching down the west coast could bring the disease to the area this summer.

A local newspaper quoted a ­National Chicken Council spokesman as saying: "This is certainly the biggest issue facing the industry today, no question about that."

But the picture is by no means bleak. The state, which has some of the best growing regions in the world and stringent growing standards, is in a stronger position than most to cope with issues that are being felt around the globe.

It is also home to some very healthy produce, such as pomegranates, prunes and almonds, all of which are growing in popularity. Many growers see huge scope for expansion into the UK.

Stacey Humble, associate director for global marketing at the Almond Board of California, says: "Production is increasing and ­people in the UK are becoming more aware of the health properties of almonds. This is a very good time for the industry."n