view current print edition




California citrus survives first freeze of year with upside

by Tim Linden | November 30, 2010
Though temperatures dipped into the high 20s for several hours during the two nights surrounding Thanksgiving day, the California citrus crop emerged unscathed and even improved, according to California Citrus Mutual President Joel Nelsen.

He explained that the private weather forecasting and temperature monitoring that CCM does for the industry allowed growers to be well prepared for the low temperatures and to take preventive measures. For the most part, that meant flooding the fields with running water and using wind machines to circulate the air and raise the temperature a few degrees. The running water and saturated fields can increase a field's temperature as much as four degrees. The short duration of the freezing temperatures resulted in no damaged and actually could improve the color of the crop and help the citrus withstand future freezes this year.

Mr. Nelsen explained that the first fruit every year has a tendency to be green, which packingshed operators combat with an ethylene gas shot during the storage process. He said that colder temperatures help the fruit color, and he predicted no gassing will be needed this year, which can have a negative effect on quality.

In addition, the CCM executive said that the colder temperatures during the growing season cause the fruit's skin to thicken as it matures, which can add a bit of internal frost protection throughout the year. Mr. Nelsen said that California's San Joaquin Valley, where the vast majority of the state's citrus is produced, is susceptible to freezing temperatures typically between November and February. "Our forecast shows that our next potential frost warning will be on December 16," Mr. Nelson said Nov. 30.

He noted that as the date grows nearer, detailed and specific area forecasts will be posted on the CCM web site so all growers can prepare for the colder temperatures. He said that if there has been no rain prior to the freezing nights, growers can saturate their fields and put other preventive measures in place.

Mandarins, with their thinner skins, are most susceptible to the cold weather, but any citrus can be damaged if the temperatures fall far enough for long enough. Temperatures in the mid-20s for an extended period would most likely result in significant damage.

While no damage was reported, CCM did reveal that the preventive measures do take a financial toll. It estimated that the two nights of below-freezing temperatures resulted in increased cost to the industry of about $15 million.

Mr. Nelsen said that this year's on-tree crop -- currently estimated at 95 million 40-pound carton equivalents -- could be the second largest in the industry's history. The economic situation for the citrus industry has been fairly good for the past decade, leading to increased plantings.

The cold weather also visited Arizona a few days later, but Mr. Nelsen said that he had heard no reports of damaged fruit in that state. Again, it appeared as if the temperatures did not fall far enough for long enough to damage the oranges and lemons grown in the farming areas of central Arizona.