December 4, 2013

Protecting Citrus Against A Possible Freeze
By Laurie Greene, Associate Editor
A Wind Machine Standing By to Help Protect

Citrus as a Freeze Moves into the Valley.
Philip LoBue, President and CEO, LoBue Citrus, a full-service grower, packer, and citrus shipper, based in Tulare County, spoke with California Ag Today.

According to LoBue, this week is a typical freeze event, though slightly earlier than usual. So, he is taking ordinary precautions with his citrus by using well water and wind machines.

Generally, early afternoon water application using standard irrigation, in this case micro-sprinklers within rows, creates a microclimate effect of surface heat. As the temperature drops at night, water freezes and gives off energy (heat), benefitting the trees. In the sunlight the next day, water melts into the ground allowing the ground to hold more heat during the day, and so the cycle continues.

The freeze stirs up an inversion layer 30 feet above ground at the treetops. Tonight’s inversion in the central part of the central San Joaquin Valley will be weak according to LoBue because the inversion’s elevation will be only one or two degrees warmer, and not six degrees for example.

The extent of freeze damage on crops depends upon the actual temperature, length of exposure time, and precautions taken. In citrus groves, the initial freeze damage starts outside of the grove on its borders and on the exterior of the fruit exposed on the treetops. The exterior rind of the fruit becomes physically damaged before the interior is affected. Exterior rind ice marks and other visual markers change the fruit’s export quality and value. As the freeze persists, the interior of the fruit becomes susceptible to damage.

LoBue says farmers are already taking additional standard precautions such as checking batteries for diesel or propane wind machines and copper or aluminum wiring for electric wind machines.

Of note, a brutal freeze on December 23, 1991, destroyed all fruit yet to be harvested.As a result, LoBue Bros. (former company name) shut down for most of the year. When it became apparent that government employment programs were inadequate in addressing the needs of unemployed workers, the LoBue staff and management secured both private sector and additional government assistance to help workers obtain food and shelter until the next season's crop. LoBue Bros. received statewide recognition for its efforts on behalf of these workers.

Nearly 80 years in business, LoBue Citrus is an independent, family-owned grower, packer and shipper of fresh citrus and citrus juice products, including navel oranges, mandarin oranges, specialty citrus, lemons and juice.