Growers are using freeze protection measures including wind machines in the face of extended cold temperatures. ( Photo courtesy California Citrus Mutual )

In some areas of California’s Central Valley, temperatures hovered in the low 20s for as long as five hours the night of Feb. 19 and into the morning of Feb. 20, putting citrus in the region in jeopardy.

The freeze could mean a smaller 2018-19 crop.

California Citrus Mutual reported that growers started with freeze protection measures the morning of Feb. 19, running water in groves to keep the orchard floor moist and using wind machines to bring up temperatures. Some companies started wind machines as early as 10 p.m. that day, and on average growers ran them for eight hours.

The industry is concerned about the possible effect on the 2018-19 crop because warmer-than-usual temperatures the past few weeks prompted trees to start blooming 2-4 weeks sooner than normal. Big swings in temperature — from “spring-like” to the 20s, for instance — can cause the young blooms to drop, California Citrus Mutual said.

Growers will start checking for frost burn on new plant growth over the next few days to assess damage.

Companies do not expect the current crop to be affected because fruit still on the tree has good size and sugar content, which can protect the fruit from freeze damage.

The Associated Press reported that hard freeze warnings were set to be in effect again the night of Feb. 20 and into the morning of Feb. 21.