For even more recent coverage on frigid weather in Texas and New Mexico and what may become of the onion and citrus crops, see Texas braces for another cold night.

(UPDATED COVERAGE, 5:12 p.m.) An unprecedented February cold snap in Texas’ Rio Grande Valley could damage onions and other crops, shippers and officials say.

Periods of sustained sub-freezing temperatures in the valley are not unheard of, but David DeBerry, onion category manager for Edinburg, Texas- based Frontera Produce Ltd., can’t remember one in February. In the past, they’ve been in late December.

“This late in the season is a new game for us,” he said. “I really don’t know what to expect. I don’t know if it’s going to be 5 to 15% of the onion crop, or 40, 50 or 60%.”

DeBerry is certain, however, that the cold snap will have some effect. Double centers, in which two onions grow from one root, and bolting are among possible problems growers will look for, he said.

Frontera is expected to begin harvesting March 5-10, DeBerry said. By Feb. 18-25, the company should know how much damage was caused by the cold. 

South Texas growers of citrus, onions and other commodities dodged one cold-weather bullet the night of Feb. 2-3, but more cold weather and possibly sleet or snow was still a concern Feb. 3.

On Feb. 2, the National Weather Forecast predicted temperatures in the Rio Grande Valley could dip into the low 20s or even upper teens the night of Feb. 2-3.

Fortunately for growers, it didn’t get nearly that cold, said Mike Martin, Rio Queen Citrus Inc., Mission.

“I found a low of 28, but most of the citrus acreage we have was more like 29 to 31,” Martin said. “It didn’t dip below freezing until after midnight. Durations and extremes were not nearly bad enough to cause even leaf burn.”

Rio Queen also had no concerns about its onion crop, he said.

“It just wasn’t cold enough, long enough,” John McClung, president of the Texas Produce Association, said Feb. 3. “We’re concerned, and we’re watching it very carefully, but there is no obvious damage as of today.”

Lows the nights of Feb. 3-4 and Feb. 4-5 were expected to be in the upper 20s, though wind gusts of up to 45 miles per hour were possible, according to the National Weather Service.

Hard freeze, winter weather and windchill warnings all were in effect for the night of Feb. 3-4.

The high winds could desiccate citrus plants, causing damage, said Ray Prewett, president of Mission-based Texas Citrus Mutual and executive vice president of the Mission-based Texas Vegetable Association.

The precipitation forecast could actually help protect citrus from the cold, said Prewett and Richard Walsh, marketing director for Edinburg, Texas-based Healds Valley Farms Inc.

That said, Prewett pointed out that valley growers have little experience with ice on plants in general, and with heavy winds blowing on iced-over plants in particular.

Even if damage is limited, the cold snap could disrupt movement at a time when demand for Texas citrus is very strong, and when the industry was just beginning to recover from lost business related to changes in sweet orange scab regulations, Walsh said.

The citrus season is far enough along that Prewett is cautiously optimistic trees have had enough dormancy to prevent extensive permanent tree damage, should temperatures dip into the low 20s.

On the vegetable side, onions exposed to extreme cold could develop double centers, Prewett said.

“And if it makes the tops go down, the onions are not through growing,” he said, citing another risk. “There are some concerns about onions.”

Watermelons and other vegetables, including leafy greens and even cabbage, which is hardier than many vegetables, also could be at risk, Prewett said.

Meanwhile, in Arizona, it didn’t get cold enough to damage fruit the night of Feb. 2-3, said J.D. Cronk, a grower for Mesa-based Citrus Heights Farms.

“It got down to 26 or 27, but it needs to stay below 27 for four straight hours,” he said.

The National Weather Service, however, did forecast a possible low of 25 the night of Feb. 3-4 in Mesa.

Chris Ciruli, partner in Nogales, Ariz.-based Ciruli Bros., said growers and importers will assess the effects of low temperatures the week of Feb. 7. Temperatures in Culiacan, Sinaloa, were expected to dip close to freezing — perhaps 36 degrees — but fields in Hermosillo will be more susceptible to frost damage, he said.

In addition, temperatures have slowed the rate of picking, especially for open-field product. Peppers and eggplants have dropped a size, and that may continue for product harvested the second week of February.

Freezing temperatures in Nogales caused no disruption in business, Ciruli said.

National editor Tom Karst contributed to this story.

Cold could damage Texas citrus, onions