Part of the U.S. citrus industry is currently trying to make seeded fruit part of its past. California orange growers are pushing the envelope by growing more seedless navel oranges and lightly seeded Mandarin orange varieties in colder areas. The last time winter temperatures were low enough to cause significant tree damage in the prime San Joaquin Valley area was over a decade ago, and the lack of serious frost damage to citrus in the surrounding areas is now luring in more prospective citrus growers than ever before.
Unfortunately, for the once very popular Valencia orange variety, fewer growers are now planting the seeded Valencia’s and are instead planting more seedless navel oranges and Mandarin varieties. Consumers have also shown a shift in preference toward the flavor of navels and Mandarins over Valencia’s too. However, the predominantly winter harvest times for the navel and Mandarin varieties as well as the expansion into historically colder areas has now moved frost-protection equipment to the top of the industry’s priority list.
For those growers planting their orange trees around the edges of the historically favorable San Joaquin weather pocket, wind machines have become the number one piece of must-have frost-protection equipment. Wind machines help keep the air around orange trees moving and several degrees warmer than the still, cold air temperatures that would otherwise predominate. Wind machines will protect a citrus crop in most normal winter weather, but they cannot completely protect it when the temps drop below freezing for extended periods.
One new wind machine will cost a grower about $20,000 installed and will provide frost protection for about 10 acres, making protection for a newly planted 100-acre citrus grove a $200,000 proposition. The grower will also have to wait about three or four years before he gets any of his wind machine investment back because it takes young orange trees at least that long to produce their first commercially viable fruit.
Another problem facing orange growers switching to seedless varieties is how to prevent bees from transferring seeded pollens to nearby seedless hybrids. The hybrids are very susceptible to seeding and some seedless growers now incur the extra cost of placing extensive netting over their trees in the early spring in anticipation of heavy bee activity in and out of nearby seeded orchards. In order to continue catering to the current consumer preference for seedless oranges, the growers will have to balance their expenditures against the prices they can get for their navel and Valencia orange crops over the next five years or more.