As February got under way and walnut growers were wrapping up their pruning operations, prospects for this year’s crop in Butte County looked promising.
“In this part of northern California, January was relatively dry, but a lot of rain in November and December refilled the soil profile with moisture,” says Joe Connell, University of California Cooperative Extension Farm Advisor for the county. “In fact, by the end of December, rainfall was ahead of normal. Everything is green and the trees will remain dormant until early to mid-March.”
That’s when growers will begin see what, if any, damage orchards may have suffered from the frigid temperatures that hit the area in late November.
“Sometimes, an early cold snap like that can cause some winterkill in walnuts, especially young trees that were growing more vigorously and weren’t really dormant yet,” Connell says. “We’ll know better when the trees begin to leaf out.”
Trees adversely affected by the freezing weather could exhibit some dieback of smaller branches and limbs, requiring pruning to remove dead wood, he says.
Meanwhile, growers are beginning their weed control programs, spraying herbicides in a strip down the tree rows. Many use contact herbicides to kill any weeds that come on early in combination with preemergence materials to prevent growth of later-germinating weeds. Mowing the row middles will begin when the trees start budding out March to April.
The Pacific storms stopped in January, but picked up again mid-February, bringing more rain, show and cold temperatures.
“It’s hard to say where we’ll end up in terms of irrigation water supplies for this season,” Connell says. “But, reservoirs have been filling and the percentage allotment delivered to surface water users is expected to increase this year.”