Citrus and other growers throughout Riverside County were keeping a close watch on low nighttime temperatures drop this week, though there appeared to be no serious concerns about crop damage.
"There are a lot of navel oranges and avocados on the vine in the Riverside and Temecula areas, and there are a lot of row crops of vegetables in the Coachella Valley ... so the growers are monitoring temperatures," Deputy Riverside County Agricultural Commissioner Ron Bray said.
According to the National Weather Service, the low in Riverside this morning was 38 degrees and about the same in Temecula, while Palm Springs settled at 42.
Crop damage is typically the result of prolonged exposure of immature fruits and vegetables to subfreezing temperatures, according to state agricultural officials.
The Weather Service is forecasting temperatures in the Riverside metropolitan area to dip into the low to mid 30s for the next two nights.
A frost advisory was in effect this morning. The freezing mark is 32 degrees.
"Although we do not expect to need to use frost protection as the forecasted frost will not go below 32 for very long tonight, we have people in place to turn on the micro sprinklers ... and start the wind machines if necessary," said UC Riverside Director of Agricultural Operations Petty Mauk.
Mauk explained that watering plants in freezing temperatures can insulate them from the cold because as the water freezes, it releases heat.
UCR manages almost 500 acres of citrus groves and other crops adjacent to the Riverside campus and another 540 acres at a Coachella Valley research facility.
"Using (precautionary) measures last year, even our young avocado trees survived 26-degree freeze events," Mauk said.
The last hard freeze countywide was in January 2007, when local growers and agricultural interests throughout the state suffered millions of dollars in losses.
"We've had localized freeze events in the last few years, but nothing like 2007," Bray told City News Service. "Thirty-two degrees is not horrible for most commodities. Some growers like a certain period of low temperatures" to toughen up their trees in case of futures freezes.
Riverside County's agricultural industry generates $1.25 billion in economic activity annually, according to the Agricultural Commissioner's Office's 2012 Crop Report.
The county has 222,789 acres of harvested land. The highest-yielding crops are in the Coachella Valley, from which $543.6 million in produce was grown and exported last year, the report said. --City News Service