Citrus growers dodging freeze bullet

Four nights of freezing temperatures did little or no damage to the area’s citrus crops, California Citrus Mutual reported Wednesday.

The latest cold snap did not produce damaging temperatures Monday or Tuesday nights, but growers had to protect again on Wednesday night.

Lows in the upper-20s were the worst to appear in the citrus belt, with Tuesday night being the coldest.

“Temperatures have been right at the levels where growers have been successful keeping temperatures out of the danger zone,” said Bob Blakley, director of Industry Relations with CCM.

Lows predicted for Sunday and Monday did not materialize because of cloud cover. Tuesday nights lows began to dip, but then fog moved in and temperatures leveled off, said Blakley.

West Porterville had the lowest temperature Wednesday morning at 27.2 degrees Fahrenheit, but that was just for a few minutes. East Lindsay recorded a 27.9 degrees and Terra Bella only dropped to 32.9 degrees.

There was a chance Wednesday night into Thursday morning could be the coldest so far, but Blakley said it appeared fog would settle in again and keep temperatures up. If not, lows could dip into the mid-20s.

The National Weather Service in Hanford predicted a low of 27 Thursday morning in Porterville, and as low as 25 in some rural areas, “but if it gets foggy, it could end up 28-29 degrees,” said meteorologist Jim Dudley.

After Thursday night, it should warm with temperatures above freezing for the next several nights. However, that will mean more widespread fog. There are no storms on the horizon, said Dudley.

Growers have had to take measures to keep temperatures up, although not for long durations and nothing compared to last year when there was nearly a month of cold temperatures in December into January.

At most risk are mandarins and lemons. The temperature threshold for mandarins is approximately 32 degrees for a duration of two hours, whereas navel oranges can withstand cold temperatures as low as 28 degrees for a four-hour duration before frost protection mechanisms need be utilized,” said CCM President Joel Nelsen in a press release. According to reports, mandarins have experienced 13-14 critical nights season-to-date, compared to over 30 nights for the same time period last season. Only 3-5 nights of critical temperatures were reported season-to-date for the navel crop, versus 24-25 nights at this point last season.

Blakley said both mandarins and navels are in better shape than a year ago. The rind is thicker and the sugar content higher, and combined they mean the fruit can better withstand colder temperatures than a year ago when the fruit was not as mature.

“It would take 25-26 degrees for a significant amount of time to be concerned,” said Blakley.

“Growers reported running wind machines on mandarins for an average of 8-10 hours last night, versus 0-5 hours for the more cold tolerant navels. The use of wind machines and a warm inversion layer worked to keep temperatures in the groves up by about 3-5 degrees,” said Nelsen.

Any efforts to protect their crops is expensive for growers. CCM estimates it cost approximately $30 per hour to run a wind machine. Then there are labor costs.

There are 16,300 wind machines at work in the Central Valley. Overall wind protection cost in the Central Valley is approximately total $550,000 per hour across the entire industry. The industry spent roughly $100 million on frost protection during the 2011-2012 season.

Blakley said only about 15 percent of both the mandarin and navel orange crops have been harvested, but added, so far, the winter has been milder than normal in terms of cold.