Pecan growers in New Mexico’s Mesilla Valley welcomed the season’s first monsoon rains in early July. But no one, including Nelson Clayshulte, is saying that it’s over for the long-standing drought that has left him and Valley growers with little district river water to irrigate their fields.
“We continue pumping water and trying to keep everything wet,” he says.
Clayshulte, and his brothers, Marshall and John, have 800 acres of pecans near Mesilla and farther south. The main variety, Western Schley, is pollinated by Wichita, Bradley and a few Pawnee trees.
“Depending on the area, the Valley received from about one-half to an inch and a half of rain,” he says. “Normally, we get most of our annual rainfall, about 5 to 8 inches, during the monsoon season, which usually runs through the end of September. During that time, we may go two or three weeks with no rain, or we may get two inches all at once.”
This past winter was wet for Mesilla Valley growers, but rain didn’t fall again until May, when Clayshulte’s orchards received about half an inch.
As the monsoon season began, nuts on his trees were developing on a normal schedule and had grown to about three-fourths inch long.
Last year, says, the trees produced a good on-year crop; so far, production this season appears to be typical for an off-year.
“The trees are looking pretty good,” he says, “although some are still suffering from the hard freeze a year-and-a-half ago when temperatures dropped below zero for 96 hours.”
Many of his trees escaped damage from that cold snap, but those those that didn’t, particularly the older ones, suffered die-back of fruit wood and major limbs. The damage varies by variety and soil types, he says.
“We pruned some of the damaged trees pretty heavily this past winter and that has definitely helped them recover. We’ll do the rest next winter.”
Aphids are his major insect pests. In mid-June, he sprayed some of his orchards where yellow aphid numbers were beginning to increase. Normally, one application a season is enough to control them, but it requires prompt action.
“Yellow aphids can build quickly,” Clayshulte says. “If you don’t catch them before you get a monsoon rain, you may not be able to get into the fields to spray for a while.”
Now, he’s continuing to watch for any more yellow aphids. Soon, he’ll be on the lookout black aphids — which usually show around the end of July or early August — and will treat for them as needed.
In May, he sprayed the first generation of pecan nut casebearer, based on the number of moths caught in pheromone traps. “My experience has been that if you can control the first generation of the season, usually you won’t have problems with the remaining generations.”
The Clayshulte brothers’ trees include some their father planted about 60 years ago. This year, they planted some new trees, spacing them 32 feet apart within rows. The rows are 32 feet apart.
Tree spacings commonly used by Mesilla Valley pecan growers range from 20x30 to 60x60, Clayshulte says. In his case, trees have been planted on various spacings — 20x40, 25x35, 40x40 and 45x45, depending on the field.
“If you ask 10 growers what’s the best spacing for pecan trees, you’ll get ten different opinions,” Clayshulte says. “My brothers and I keep changing our minds as we go along. It would have been easier if we had figured out the best spacing earlier. But, based on our experience, I think our new 32x32 foot spacing will be the best for us in terms of yield and quality.”