NMSU Pecan Research to Benefit Growers in the West
Date: May 14, 1997
Editor: D'Lyn Ford (505) 646-6528, dlford@nmsu.edu
LAS CRUCES -- It's back to the basics for pecan research at New Mexico State University's Agricultural Experiment Station.
How nutrients in the soil affect the bottom line -- the end-of-season yield -- is essential information for farmers managing any crop. Farmers need to know when and how much nitrogen fertilizer and other nutrients to apply for the best results.
But pecan growers in New Mexico haven't had that kind of information and have been following guidelines largely developed in other western states.
"This is a basic agricultural approach that has not been done systematically in New Mexico for pecans," said Tim Jones, an NMSU soil scientist.
A remedy is in the works with the Western Irrigated Pecan Initiative, funded by the USDA. A $250,000 annual grant pays for NMSU research projects that support production of 58,000 acres of pecans worth more than $60 million in Arizona, New Mexico and West Texas.
The grant supports work by as many as seven NMSU researchers including Jones and two other soil scientists, Bobby McCaslin and Bill Lindemann.
"We need to understand how to manage water and nutrients in irrigated pecan orchards to improve the efficiency of water and fertilizer use," Jones said. "Applying fertilizer efficiently saves money and cuts down on potential negative environmental effects."
In one study, the researchers are comparing yields to how much water is applied and the nutrient levels in soil and tree leaves and nuts.
This study includes 15 orchards in southern New Mexico from Hatch to Anthony, covering a variety of soil types. Esteban Herrera, horticulturist with NMSU's Cooperative Extension Service, arranged for researchers to work in existing production orchards to get more realistic results.
In another study, the researchers are using a special type of nitrogen to track the nutrient's movement from the soil to the trees and nuts. They hope this will help in developing pecan fertilizer recommendations for New Mexico.
This study involves just three trees located in David Salopek's orchard south of Las Cruces, but it requires a lot of intense monitoring.
For example, researchers have placed 27 tubes 6 feet deep around each tree. They then put a probe down the tubes to monitor water contents in the soil before, during and after irrigating. This will help them understand how much water is being used by the trees and how much is returned to the ground water.
Salopek has cooperated with NMSU researchers for the past five years. He irrigates 10 acres of pecan trees under study during the day and keeps heavy equipment away from the three trees surrounded by tubes.
"Anytime we can get valuable knowledge to do a better job, it's worth the inconvenience," Salopek said.
Another emphasis of the research funded by the grant is on managing pecan pests like aphids and the pecan nut casebearer, said Joe Ellington, NMSU entomologist.
Ellington looks at controlling the pests biologically by introducing other beneficial insects that prey on the pests, cutting down the need to spray the orchards with chemicals.
"When we use pesticides too heavily, very often the pests build up resistance, and we kill the beneficials," Ellington said. "We're trying to diversify our methods of controlling Pests, because the silver bullet approach usually ends up creating resistant bugs."
In a variety of studies, he's looking at the numbers of pests and beneficial insects in the orchards and at different cultural practices growers can use to increase the beneficials.
One way is to find out what cover crops planted under the pecan trees make the best homes for the beneficial insects. This season, he's concentrating on small grains like wheat, rye and barley as cover crops.
Future collaborative research between entomologists and soil scientists may examine how cover crops affect the pecan trees' water and nutrient needs. "Anything we do under the trees is likely to affect the uptake of nitrogen and other soil nutrients, and certainly modify the amount of water necessary," Ellington said.
For now, the scientists are sticking to the basics.