If you travel the 100 miles between Modesto and Fresno in California's Central Valley you'll see quite a few almond orchards. They cover 580,000 acres of the state, making it one of its biggest industries.

The state is the sole producer of almonds in the US and supplies 80% of the world's consumption, with a farm value of $2.2bn.

Almond crops have been affec­ted by poor weather, with production dropping from a high of 492,000 tonnes in 2002 to 412,000 tonnes last year. Yet supply is projected to grow to 700,000 tonnes by 2010 as more growers enter what has become a lucrative market.

"The number one reason that people eat almonds is because they taste good, but health is a big factor," says Linnea Trujillo, manager of global marketing and communications at the Almond Board of California. "They can help lower cholesterol and have potential as a weight-loss food."

The USDA recently made almonds part of the US recommended healthy diet, and Trujillo believes health is the key for expan­ding into the UK.

The UK is the tenth largest ­export market, taking more than 9,000 tonnes of almonds. There is room for growth though, she says, as UK current per capita consumption is only half of that in the US.

According to the Almond Board, shipments to western Europe have grown by 5% over the past five years and prices are set to drop as a result of increased supply. New nut retailers in the UK, such as Cranberry, are also helping sales.

Demand is growing in the US and across the Atlantic for ­organic almonds, says Rick Kindle, vice president of operations and marketing at almond processor Gold Hills Nut Company. "Organic is less than 5% of the market but we are getting many requests for it," he says. "The hard part is getting enough growers to convert, but more and more of them are. ­Organic hasn't gone through the price adjustments yet. ­Organic almonds sell at $8 per pound compared with $3/lb for conventional."

Despite such promising develop­ments, the almond industry is at risk of becoming a victim of its own success. Gabrielle Ludwig, ­Almond Board senior manager for global, technical and regulatory ­issues, says that California is faced with rising air pollution issues. During harvest, when almond trees are shaken to remove the fruit, it becomes a high dust contributor. "California has weather conditions that make air pollution a bigger problem than other places in the US," she says. "It has mountains on three sides, six months of no rainfall and a tremendously ­increasing population. We are ­always being looked at."

Ludwig says growers have to pay the costs of reviewing conservation and pollution plans as well as retrofitting equipment to limit dust output. Costs are on the rise and could eventually force some growers to leave the industry.

Sprawling ­urbanisation is an ever-increasing threat, and ­almond orchards now often sit apologetically beside freeways and houses. "The biggest problem is development" says Ludwig. "If you have land in the family for 60 years and the town grows outward you can sell it for lots of money and retire. But if you continue to farm you end up having neighbours who don't want to deal with the noise, pesticides and dust." n