It was another long night for citrus growers as temperatures dropped below freezing throughout the Central Valley and Ventura County last night. In the Central Valley, a decent cloud cover kept temperatures from dropping as low as expected. Generally, temperatures hovered in the 27 to 29 degree range for most of the night and early morning. In Ventura County, temperatures bottomed out around 24 to 25 degrees. Overall, this marked the coldest night this winter.

Growers throughout both regions reported running wind machines for several hours to protect the State's $3.8 billion dollar citrus crop. Additionally, water was run in colder spots to moisten the ground in anticipation of the cooler temperatures. As the warm air rises from the moist ground, wind machines effectively trap and circulate warm air in the grove. When temperatures fall below critical levels, a two to four degree increase can prevent significant crop losses.

Navel varieties can tolerate temperatures as low as 27 degrees without threat of damage, whereas Mandarin varieties tend to be susceptible to some damage at temperatures below 32. Lemon varieties fall in the middle, tolerating temperatures as low as 30 degrees. The key factor is duration of time at or below these thresholds.

We are currently a quarter of the way through the citrus season, which is anticipated to go through mid-June. At this point in the season, cold weather is to be expected and at current levels is beneficial for fruit quality, color, and flavor.

According to the county crop reports, 81 percent of the state's citrus crop is produced in the Central Valley. This represents 80 percent of the total value of the state's $3.8 billion citrus industry. A recent report by University of Riverside estimated that the citrus industry creates over 22,000 jobs statewide.