The navel orange season is off to an early start, lemons are in tight supply and fetching strong prices and growers remain on alert for signs of citrus greening and the Asian citrus psyllids that spread the dreaded disease, say citrus growers in California and Arizona.

Growers started harvesting early varieties of navel oranges the week of Oct. 7, said Bob Blakely, director of industry relations for California Citrus Mutual, Exeter.

“We’re earlier than we have been the last couple of years,” he said.

The first navels were expected to enter the market the week of Oct. 21.

Sizing is more desirable than it has been the past few years, he said, and sugar levels are good, “which is a precursor of good flavor.”

“We’re pretty optimistic about the start of the season,” Blakely said.

The 2013-14 California navel crop is estimated to be 88 million cartons, down about 2% from last year.

Meantime, lemons, which were in short supply during the summer, were still playing catch up this fall and could remain tight for the next couple of months, grower-shippers said.

Growers in Mexico, Chile and Argentina all experienced weather problems, and one grower said prices in mid-October were running $3 or $4 per box higher than last year.

Growers are picking lemons in the California desert growing region and in Arizona.

Size and quality are said to be good, and most growers expect to have volume that is slightly greater than last year.

Specialty citrus, especially “easy peelers,” continues to find favor among consumers.

Mulholland Citrus, Orange Cove, Calif., which offers clementines and mandarins, hoped to start harvesting by the end of October, a few days earlier than last year.

Johnston Farms, Bakersfield, Calif., has boosted its satsuma mandarin acreage.

The company packs more than 300,000 25-pound boxes of satsumas, murcotts, gold nuggets and Tahoe golds.

Grower-shippers in California and Arizona would love to make it through the season without finding any signs of citrus greening disease, also known as huanglongbing or HLB.

Although the Asian citrus psyllid, which transmits the disease, has been found in both states, none that are carrying the disease have been detected in commercial citrus growing areas.

The California Citrus Pest Disease Management program provides about $15 million funded primarily by an 8-cents-per-carton assessment on growers to fight the disease and the psyllid, and the U.S. Department of Agriculture Animal and Plant Health Inspection Service provides the state with about $10 million through the Citrus Health Response Program.

A number of citrus grower-shippers are expanding or improving their operations.

Sherman Oaks, Calif.-based Sunkist Growers Inc. has added a grower, Terra Bella, Calif.-based Growers Citrus Packing, which expects to pack 1.6 million cartons for Sunkist annually.

Mulholland Citrus, Orange Cove, Calif., has consolidated its offices and plans to launch a product — SweetDelite mandarins — and a new website this fall.

Santa Paula, Calif.-based Limoneira Co. has acquired Yuma, Ariz.-based Associated Citrus Packers Inc. Associated Citrus Packers grows approximately 950 acres of lemons along with 350 of other crops.

Cecelia Packing Corp., Orange Cove, expects to receive its GlobalG.A.P. certification in December.