Contrary to most pecan growers in New Mexico’s Mesilla Valley, this is an off-year for Greg Daviet’s 250 acres of trees. He is operations manager for Dixie Ranch, near Las Cruces, which his great-grandfather started in 1905.

A late-May nut count indicates his 2013 crop is likely to be average in size for an off-year crop. Average is about 1,400 pounds per acre. “We’re not expecting anything out of the ordinary,” he says.

That’s in marked contrast to last year when yields of nearly 3,200 pounds per acre topped the ranch’s previous best on-year crop by a long shot. “We've seen a steady increase in our yields over the past decade, but last year really stood out”, Daviet notes. His previous on-year crop produced 2,500 pounds per acre.

“I wish I could explain last year’s yields,” he says. “I could point to at least 10 things we do differently now. But it’s hard to say exactly what accounted for last year’s record production, other than that we’re always working to improve production.”

The oldest pecan trees on the ranch were planted by his grandmother in 1965. The youngest trees are almost 40 years old. About 80 percent are Western Schley. The rest are divided equally between Barton and Bradley. All are planted on 40-by-40 foot spacing.

Following unseasonably cool weather early this year, Daviet’s trees began leafing out April 10. The crop has remained about a week to 10 days behind the usual pace of maturity through May. However, above normal temperatures during the last half of May could allow the crop to catch up, he notes.

His orchards appear to have escaped the worst of the sub-freezing temperatures during bloom that devastated crop prospects this year for other New Mexico pecan growers.

“At the time, I didn’t see any frost damage in our blocks,” Daviet says. “But, now I’m seeing some symptoms of injury that could be related to the freeze.”

One of his major insect threats — the pecan nut casebearer — has shown up in greater numbers this season that he’s seen in a long time. Last month was the first time in the past five or six years that he’s had to apply a pesticide to control them this early.

For good measure, he included a systemic in that treatment to target yellow pecan aphid, another of his perennial pests. His main defense against this threat for the past two decades is the ladybug. He puts them out in his orchards weekly, beginning the last week of May, for about six weeks or until the aphids die out.

Water problems

With the drought continuing in this and other areas of the Southwest, he’s expecting the Elephant Butte Irrigation District to deliver only 3 acre-inches of surface water for flood irrigating his pecan crop this year. That’s less than 10 percent of a full district allocation. Also, it represents less than 5 percent of the total 66 inches of water that he uses each year to irrigate his fields. The rest comes from his wells.

As he and other valley growers continue to draw water from the ground, they’re forced to go deeper to get it. Sixty years ago, a 100-foot well was common in the area.“Today, it’s not unusual for a well to go down 300 to 400 feet to get good quality water,” he says. Wells 600 feet deep are not uncommon.

“Here in the central part of the valley, we easily have 1,000 feet of water below us,” Daviet reports. “But, in the northern region of the Valley, some growers have no more than about 80 feet of usable aquifer. When we drill a well on our ranch, we blank out the first 150 feet to block out the salts in the soil. But, some growers don’t even have 150 feet of water in total to draw from.”

Making the most of every drop of water is Daviet’s top management priority. “It’s so critical to our success in growing pecans that it receives the lion’s share of our focus and attention,” he says.

Water management extends beyond such basics as matching irrigation timing and rates to the tree’s water requirements. It includes such practices as amending soils to improve water holding capacity, leveling fields with lasers to improve water delivery efficiency, sinking wells deeper to improve water quality by minimizing salinity levels, replacing ditches with pipelines to reduce water losses and replacing outmoded small-port pipe gates with large, high-flow turnouts

Second in importance only to water is an aggressive pruning program. It’s designed to make the most efficient use of the sunlight. He prunes them early in their life and often thereafter.

“We don’t let trees grow to the point where they need to be pruned. Once we start cutting a tree to the size and shape we want, we continue pruning regularly to keep it that way. In just the 10 years we’ve been doing this, we’ve seen significant production increases.”

Meeting the nutritional needs of his trees remains the most challenging aspect of Daviet’s crop management. Currently, he uses a combination of urea-sulfuric acid and UAN 32, which he bands within 10 feet of the tree trunks, to provide the trees a total of 300 units of actual nitrogen per acre annually.  He applies 50 units in the first of April, followed by 100 units each at the first of May and first of June. He feeds his trees the remaining 50 units in early August.

Daviet makes the first of two 25-unit applications of phosphorus each year at the first of April and the other at the first of August. His phosphorus applications include a total of 20 units of potassium a year.

“Crop nutrition needs are very site specific and depend on a lot of interactions of such factors as soil characteristics and water quality,” Daviet says.

This report is from Tree Nut Farm Press, a twice-monthly electronic newsletter published by Western Farm Press during the growing season. This edition was sponsored by Valent USA.  If would like to receive Tree Nut Farm Press go to the Western Farm Press home page (westernfarmpress.com) and sign up for it and other Farm Press electronic newsletters.