Weed Science

Cheryl Fiore
Research Specialist

Jill Schoeder
Professor : Entomology, Plant Pathology, and Weed Science

"We have been conducting field and greenhouse research at the Leyendecker Plant Science Research Center since 1988. Research has included field evaluations of candidate herbicides for use in chile pepper, onion, cotton, grain sorghum, corn, and pecans; determination of the economic benefit of herbicides and cultivation for weed management in chile pepper; effect of weeds on yield and quality of chile pepper; and growth characteristics of some of the problem weeds found in southern New Mexico production systems. The research has defined the problems that weeds pose in production agriculture in New Mexico and has provided information concerning the effectiveness of herbicides in our soils and under our environmental conditions. Annual reports from 1988 through 2009 are being scanned and posted on the EPWS website, http://eppws.nmsu.edu/research-programs.html.

This research program has sponsored undergraduate and graduate student research projects each year. Many of the students conducting research projects in this program have had the opportunity to present the results of their work at a professional meeting. In addition, we maintain a weed garden for use by students taking the weed science classes at NMSU, other programs in the college, and the public. Improvements to the weed garden were made in 2004 with funding from the Rio Grande Basin Initiative.

Current projects include collaborative efforts with other scientists in the Entomology, Plant Pathology, and Weed Science, Plant and Environmental Sciences, and Extension Plant Sciences Departments. The current work can be separated into three broad areas: the interaction between weeds and other pests that are problematic in chile pepper and other crops, projects under the Rio Grande Basin Initiative, and weed biology and management.

Research continues in cooperation with Dr. Stephen Thomas and Jacki Trojan (EPWS nematology) to determine the effectiveness of annual crop rotations compared to alfalfa for suppressing the yellow nutsedge/purple nutsedge/southern root-knot nematode pest complex. Previous research has described a complex, beneficial relationship between these two creeping perennial nutsedge species and root-knot nematode; all these pests are a problem for southern NM cropping systems. In addition, past cooperative research has shown that a 3-year rotation of non-dormant, root-knot resistant alfalfa will suppress the pest complex long enough to produce a subsequent chile crop without the use of pesticides. However, the pest complex returns by the end of the season indicating that other practices are needed to provide sustained management. Research is also in progress to determine the effect of southern root-knot nematode on growth and fecundity of several annual broadleaf weeds that serve as alternate hosts of this nematode; this project is designed to provide new information on additional weed/nematode complexes and clues for sustainable management of these pests. Other collaborative research has included Dr. Soum Sanogo (EPWS, plant pathology) to determine interactions among annual weeds, nematodes, and Verticillium. Collaborative work with Drs. Rebecca Creamer and Scott Bundy (EPWS) has researched the biological interactions among the beet curly top virus, beet leafhopper, and London rocket. Scouringrush or horsetail (Equisetum hyemale) is one of the dominant species of weeds found on the irrigation canals of Elephant Butte Irrigation District in Southern New Mexico and, once established, it can cause significant water loss via ponding and evapotranspiration. Research in cooperation with Dr. April Ulery (PES, soil chemistry) and Jamshid Ashigh (EPS, weed science) is being conducted by James Hill (M.S. candidate) to determine whether the life cycle and rate of spread of E. hyemale is affected by canal ecosystem characteristics such as soil properties, vegetation communities , environmental conditions and disturbance patterns, and to evaluate potential management strategies (herbicides and competitive plants) for the weed.

We also are conducting research to determine the timing and pattern of emergence of common weeds in southern New Mexico. This information will provide us and growers with additional tools for researching and planning weed management programs. We continue to conduct research to evaluate candidate herbicides for use in chile pepper, pecan, and other crops. This ongoing effort is in cooperation with the chile commission and industry."

This document was submitted by Cheryl Fiore, a Research Specialist in the Department of Entomology Plant Pathology and Weed Science , NMSU and Jill Schroeder, Professor of Entomology Plant Pathology and Weed Science, NMSU.