California walnut farmers meeting worldwide demand

By Chris McGregor

WHEATLAND, CA—The first thing you feel is the shaking.

Like an isolated earthquake (this is California, after all), the harvesting machine shakes the tree so violently it’s hard to believe the tree is not ripped out of the ground.

Roots 10 feet deep keep the tree planted firmly as the vibration rumbles beneath the orchard, dropping walnuts, some still in the green hull, to the ground by the thousands.

This is the California walnut harvest, an intensely busy two months between September and November that produces 99 per cent of all walnuts grown in the United States.

Approximately 45 per cent of the average 334,000 tons of nuts grown annually will end up internationally in Canada, Europe and Asia.

California’s walnut industry started in the 1860s in the southern part of the state before migrating north to the Central Valley. Of the 400 different crops grown in California, walnuts rank 15th on the list in terms of overall monetary value.

Growers in California have enjoyed surging market demand for the product that comes with a number of natural health benefits.

Walnuts are high in omega-3 fatty acids, the only nut able to make the claim, which are proven to reduce the chance of diabetes, cancer, stroke, heart disease, high blood pressure, obesity and even depression.

If that isn’t enough, they contain no trans fat, cholesterol or sodium, and are a source of vitamin B6, folic acid, magnesium and protein. They are one of the best-known sources of melatonin, an antioxidant shown to lessen the risk of Alzheimer’s and Parkinson’s disease and some types of cancer.

According to a study from the United States Food and Drug Administration, “Supportive, but not conclusive research shows that eating 1.5 ounces of walnuts per day, as part of a low saturated fat and low cholesterol diet, and not resulting in increased caloric intake, may reduce the risk of coronary heart disease.”

This year, farmers are predicted a record crop of walnuts thanks to near perfect growing conditions and an eager market.

Dennis Balint, director of the California Walnut Commission and California Walnut Board expects a harvest of 375,000 tons in 2008, a new plateau for the industry.

“This is going to be another good year for the industry and another good year for the consumer,” he said.

That is the case with farmers out on the land including three generations of the Norene family who have made their living from the walnut harvest in Wheatland, California, north of Sacramento.

Don Norene runs the 750-acre operation today, with help from his son Davin. He is just one of 4,000 growers and 59 processors in California responsible for two-thirds of the world’s supply of walnuts.

“People are buying more walnuts than ever before. The health aspects don’t hurt either,” Norene said while standing among his mature trees. “Our business is booming right now.”

He said the 2008 season is shaping up to be “an exceptional year” for him in terms of overall yield and price.

The Central Valley’s fertile and well-drained loam-based soils provide perfect growing condition for the Hartley and Chandler varieties, which make up 60 per cent of the entire harvest.

Ashley, Serr, Vina and Howard are some of the more common varieties among 30 grown in the state. While it takes as long as eight years for a tree to start producing fruit, they can bear fruit for as long as 100 years.

It’s only when yields start dropping to below 1.5 tons per tree that a farmer might consider replacing it. After planting new saplings, trees are cut off about 30 centimeters off the ground and a known well-producing tree is grafted onto the stump, ensuring a consistent, high yielding orchard.

Straight off the tree, walnuts are edible, but are softer and lighter in colour than what is found in the grocery store. It takes five months for the nuts to reach maturity.

After being swept up into a trailer, the walnuts are hauled to a dryer facility where they remain for six hours to three days to get moisture content down to the desired eight per cent. 

Leaves, branches and dirt from the orchard are then blown out, leaving only walnuts that get separated by variety and grower. Shells are floated into a tank of water to remove any remaining dirt.

Walnuts are sent through a machine that removes the green hull. Next, a weight sensitive blower kicks out the smaller walnuts, leaving only the larger, more desirable jumbo walnuts behind.

A colour-sorting camera looks for the black and green walnuts, which get diverted from the production, while the prized light amber coloured nuts continue down the line.

Machines sort the nuts by small, medium, large and jumbo sizes, with samples from each lot being hand inspected. Regular samples are taken and sent to the United States Department of Agriculture and, in the case of Carriere Family Farms, a private laboratory as a precaution.

Bill Carriere runs the operation with his four cousins, harvesting 1,500 acres of walnuts southwest of Chico, California. Annually, the farm grows four million pounds of walnuts and processes another 4,000 tons. They also grow rice, olives and almonds.

In a partnership with Borges, a Barcelona-based importer of California walnuts, their 18-million pound production facility handles two per cent of all walnuts grown in California, both in shell and shelled, for other growers. Carriere Family Farms is so large that a USDA inspector is on site full time ensuring standards are met.

After sorting to determine quality based on the percentage of quality product, the farmer is paid accordingly. Size, colour, the amount of shrivel, and any insect damage influence price. The nuts are then packed, labelled and sent to customers around the world.

About 60 per cent of all shelled walnuts and 40 per cent of in-shell nuts end up in overseas markets.

In 2006, Carriere installed a shelled line that mechanically cracks the nuts that get sorted by laser into varied sizes. Every part of the nut is used, regardless of quality. Lower grade nuts are used in baking while the broken shell is used for sandblasting operations.

Business is so strong for Carriere that he’s recently added a new storage building capable of holding eight million pounds of nuts that will be filled to capacity. Tanks on the property each hold another 500,000 pounds. Carriere has five of those.

In proper conditions nuts can be stored for as long as one year. Carriere will need all of that space to help meet the growing worldwide demand for walnuts.