What is in this article?:
- Too early to tell freeze damage
- Some crops could be severely damaged
- Replanting may be one option
Pecans are a major crop in the Mesilla Valley around Las Cruces. Richard Heerema, NMSU's pecan specialist, said the varieties typically grown here are able to withstand very cold temperatures and should have been fully dormant prior to the freeze. He thinks mature and well-maintained trees sustained little or no damage. Unhealthy trees and very young trees would be more susceptible to frost damage.
Pistachios grown in Dona Ana and Otero counties may have sustained more damage than pecans, Heerema said. Temperatures below 10 degrees Fahrenheit can pose a threat to these trees. He suggested that owners scrape the bark on last year's growth with a knife or even a thumbnail to check for brown cambium, an indication of damage. "We won't really know the extent of any damage until spring growth begins," he said.
Woods Houghton is an Extension agent in Eddy County in the southeastern part of the state. He has expressed concern that most trees in his area may have sustained damage that will become evident over the next few years. He fears that the mild late fall and early winter resulted in trees that weren't fully dormant and that the prolonged very low temperatures in his area may have caused intracellular ice crystals that ruptured tissue cell membranes.
Houghton has seen some damage to fall-planted alfalfa and wheat in his area but said it is still too early to know the extent of the damage. He stressed that alfalfa is grown in many places around the world where bitterly cold temperatures are normal. In a recent article he wrote for the Carlsbad Current-Argus, he discussed his concerns about alfalfa and suggested how farmers might eventually deal with fields where productivity seems doubtful.
Mark Marsalis is an Extension agronomy specialist at NMSU's Agricultural Science Center at Clovis. He said it is really too early to accurately assess the damage to winter wheat, but that "wheat is very resilient to cold temperatures at this stage of growth." He suspects that, due to dryness, there may well be some death in the dryland wheat grown in the region and that the dry conditions will likely play a larger role in crop death than the freezing temperatures. It may be early in the spring before the full extent of damage is known.
"The late-planted non-irrigated wheat that wasn't tillered very well is the most susceptible to freeze damage," he said. "The irrigated fields where some soil moisture was present should be in much better shape." The fields he has inspected so far have only shown moderate to severe leaf burn damage and should recover if water does not become the limiting factor.
Sangu Angadi is a crop physiologist, also based at the Clovis center, whose research focuses on oilseed plants. He agreed that it is too early to assess damage accurately and completely, but he supplied a few photos of dead plants from his test plots. He reported that most of the more than 50 varieties of winter canola he is studying seemed to survive well in the test plots planted relatively early (mid-September), while the mid-October planting was nearly wiped out. While many leaves were visibly damaged in the September crop, the crowns of the plants tended to still be green.
Angadi said almost all of the winter safflower plants were killed off. They were part of a project, headed by Texas Tech University colleague Dick Auld, to develop varieties of winter safflower that will do well in the Southern Great Plains area. "If any breeding material survives this cold, it will be great news for us," he said.