Progress 10/01/01 to 09/30/06
Outputs
Research is in progress to develop practical, sustainable ways to manage the root-knot nematode-yellow and purple nutsedge complex in noncompetitive crops such as chile pepper. A single pre-plant irrigation is commonly used as part of field preparation in New Mexico. After a winter with substantial rainfall, pre-plant irrigation stimulated emergence of yellow nutsedge but had no effect on purple nutsedge emergence; however, pre-plant irrigation stimulated emergence of both species in a year with no winter rainfall. Heat unit accumulation (10 C base temperature) prior to and after emergence of the nutsedges is being used to model root-knot nematode egg production from nematodes that survived the winter inside the nutsedge tubers. London rocket is thought to be the primary overwintering host of beet curly top virus and the beet leafhopper that transmits the virus to chile pepper. Emergence was highest in October-planted London rocket, low in January/February plantings,
and did not occur for August plantings. The life cycle was 185 d and 125 d for October- and January-planted London rocket, respectively, and growth of the plant (including height and rosette base diam) was greater for London rocket that was planted in October. October-planted London rocket survived from late October through mid- to late-April, the period of time needed to serve as an overwintering host for beet leafhoppers. Research is in progress to determine the rotational crop response to trifloxysulfuron treatment in cotton. Onion, lettuce, and alfalfa planted 6-,7-, and 9-months after a layby treatment showed visual injury while wheat, sorghum, chile pepper, and watermelon showed few symptoms. Additional treatments were applied in 2006 and will be evaluated in 2007. Sampling along the irrigation canals of southern New Mexico was completed in 2006; data included GPS location, canal characteristics, soil characteristics, percent vegetation cover, percent cover by plant species, and
spectral reflectance. Canal size, reflecting water flow rate and continuous or intermittent flow, was the primary factor used to predict presence of common bermudagrass, field horsetail, curly dock, plantain species, and saltgrass were most common on the canals. Horsetail was found more often on smaller, intermittent canals while common bermudagrass and saltgrass were more common on the large, continuous canals. Additional modeling indicates that soil characteristics such as pH, sodium adsorption ratio, and the primary nutrients are significant covariates with canal size in predicting presence of the major species.
Impacts
Nutsedge tubers serve as an overwintering host for root-knot nematode and protect the parasite from fumigation; a greater understanding of the biology of the three pests is needed to identify alternative, sustainable management strategies for the pest complex. The research to determine the effect of pre-plant irrigation on nutsedge emergence and development of the three pests will enable us to develop a predictive tool for growers. The goal is to be able to suggest changes in management to reduce the impact of the nematode-nutsedge complex on vegetable production. The research to elucidate the life cycle of London rocket has provided important information to growers for managing beet curly top virus. This, along with other management approaches such as delaying thinning, is reducing the problem in the field along with reducing the need for expensive insecticide treatments that are only marginally successful in controlling the insect vector.
Publications
- Ray, J., J. Schroeder, R. Creamer, and L. W. Murray. 2006. Planting date affects phenology of London rocket (Sisymbrium irio) and interaction with beet leafhopper (Circulifer tenellus) in southern New Mexico. Weed Science 54:127-132.
- Fiore, C., X. Liu, J. Schroeder, S. Schuster, L. Murray, R. Sanderson, M. Renz, A. Ulery, O. El-Sebai. 2006. Vegetation on irrigation canals in southern New Mexico. Proceedings, Western Society of Weed Science 59:46.
- Nunez, S. C., J. Schroeder, S. H. Thomas, and L. W. Murray. 2006. Effect of Early Season Irrigation and Heat Unit Accumulation on Yellow Nutsedge, Purple Nutsedge, and Root-Knot Nematode Development. Proceedings, Western Society of Weed Science 59:106.
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Progress 01/01/05 to 12/31/05
Outputs
Research is in progress to develop practical ways to manage the root-knot nematode-yellow and purple nutsedge complex in noncompetitive crops such as chile pepper. One project is designed to determine how heat units and pre-plant irrigation affect early season population development of root-knot nematodes, yellow nutsedge and purple nutsedge. Initial results indicate that pre-plant irrigation stimulates development of yellow nutsedge but has no effect on purple nutsedge development. Additional research is in progress to map the change in distribution and density of this pest complex in an alfalfa-chile pepper rotation; the first year of the four year project has been completed. Research is in progress to determine the rotational crop response to trifloxysulfuron treatment in cotton. Onion was the most sensitive crop tested in a greenhouse bioassay; root growth was reduced by a 2.5 ppb concentration of trifloxysulfuron in a clay loam soil. An additional 68 sites were
sampled along the irrigation canals of southern New Mexico; data included GPS location, canal characteristics, soil characteristics, percent vegetation cover, percent cover by plant species, and spectral reflectance. Initial frequency analysis indicates that common bermudagrass, field horsetail, curly dock, plantain species, and saltgrass were most common on the canals. Bermudagrass was most salt tolerant compared to spurred anoda, Johnsongrass, camelthorn, horsetail, and perennial pepperweed; a finding that matched our initial assessment of canal survey data. Root growth and development of Russian thistle, perennial pepperweed, saltgrass, and bermudagrass was evaluated in response to glyphosate applications compared to untreated controls. Root development is currently being estimated from scanned images, but 45 days after treatment perennial pepperweed and saltgrass had no differences in root biomass at 0-30 and 30-60 cm, while glyphosate treated Russian thistle and bermudagrass had
significant reductions in biomass at every depth.
Impacts
Previous research determining that nutsedge tubers protect root-knot nematodes from soil fumigation was identified by the international journal Phytoprotection as a research breakthough in 2004 (Phytoprotection 85:115-117). These findings are the basis for the current work to identify alternative ways to manage the nutsedge-nematode pest complex rather than managing the individual pests. A weed garden was established in 2004 and planted with species common to the irrigation canals as well as weed species common to production fields. The weed garden was used as an educational aid at a weed science field day. We are beginning to understand the response of plants that are common to the canals to soil/water salinity and to herbicide treatment. This will help us understand the canal ecosystem and develop sustainable strategies for managing the canal system. This Rio Grande Basin Initiative research project has developed into a broad, multidisciplinary research and
extension effort that will provide pertinent information about important mechanisms of water loss from the water delivery system and will provide insight into strategies for targeted weed management on the irrigation canal system. The spectral decomposition techniques developed in the proposed experiments, educational and extension materials about water loss due to weeds, and strategies for assessing an irrigation district will be useful to other New Mexico and Texas projects under the Rio Grande initiative.
Publications
- Norsworthy, J. H., J. Schroeder, S. H. Thomas, and L. W. Murray. 2005. Southern root-knot nematode effect on purple nutsedge (Cyperus rotundus) and chile pepper response to halosulfuron. Weed Technology 19:1004-1011.
- Ray, J., R. Creamer, J. Schroeder, and L. W. Murray. 2005. Moisture and temperature requirements for London rocket (Sisymbrium irio) emergence. Weed Science 53:187-192.
- Schroeder, J., S. H. Thomas, and L. W. Murray. 2005. Impacts of crop pests, and their management, on weeds. Weed Science 53:918-922. Thomas, S. H., J. Schroeder and L. W. Murray. 2005. The role of weeds in nematode management. Weed Science 53:923-928.
- Schroeder, J., B. J. Greenfield, S. H. Thomas, L. W. Murray, and J. M. Fuchs. 2005. Root-knot nematodes (Meloidogyne incognita) increase early season growth of purple and yellow nutsedge (Cyperus rotundus and C. esculentus) emerging from large tubers. Weed Science Society of America, Abstracts 45:205.
- Nunez, S. C., J. Schroeder, S. H. Thomas, and L. W. Murray. 2005. The effects of soil temperature on yellow nutsedge, purple nutsedge, and root-knot nematode development. Proceedings, Western Society of Weed Science 58:30.
- Fiore, C., J. Schroeder. 2005. The potential for germination and establishment of select weed seed on irrigation canals in southern New Mexico. http://riogrande.tamu.edu/2005_conferencewrapup/posters/Fiore.pdf. Fiore, C., J. Schroeder. 2005. The potential for germination and establishment of select weed seed on irrigation canals in southern New Mexico. Proceedings of the Western Society of Weed Science 58:27.
- Barron, Santos, J. Schroeder, and C. Fiore. 2005. Rotational crop response to trifloxysulfuron. Proceedings of the Western Society of Weed Science 58:11.
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Progress 01/01/04 to 12/31/04
Outputs
A project to map dominant herbaceous vegetation along the irrigation canals, laterals and sublaterals in southern New Mexico was continued. Soil characteristics varied widely along the canals. Textures varied from sand to clay with organic matter contents ranging from 0.02 to 4.25% and pH ranging from 7.22 to 8.35. Vegetation type was fairly evenly split between monocots (37.7% of the sites) and dicots (33.2%). The most common species was bermudagrass, Cynodon dactylon, found at 14.3% of the sites. A species of interest, Equisetum hyemale, was found at 8% of the sites. Initial logistic regression analysis modeled the relationship between species presence or absence and soil characteristics and found a positive relationship between the presence of bermudagrass and soil electrical conductivity. The presence of E. hyemale was negatively related to electrical conductivity. Data were highly skewed indicating that additional analysis is needed before final conclusions are
drawn. The number of crayfish burrows was counted at 51 sampling sites and crayfish were caught at selected sites in 2003. The primary crayfish species identified was Oronectes rusticus, an invasive species. We sampled too few points to be able to establish a statistical relationship between burrowing activity and sampling location, vegetation, or soil characteristics. However, we found that 71% of the total burrows were found in areas with grass vegetation; 43% of the total burrowing activity was in bermudagrass. The burrows were seldom found in areas dominated by Equisetum. A greenhouse study was repeated in 2004 to examine the effect of nitrogen and potassium on the relationship between yellow and purple nutsedge and southern root-knot nematode. Initial results indicated that it appears that potassium sulfate, or perhaps the interaction between potassium sulfate and ammonium nitrate may affect the interaction between root-knot nematodes and these nutsedge species. However, the
results indicate that these fertilizers applied at these rates, alone or in combination, did not completely nullify the harmful effects from root-knot nematodes in either nutsedge species, particularly yellow nutsedge. Research was continued to identify candidate herbicides that may be used in chile pepper. Several herbicides that are in the IR4 program were tested to evaluate chile pepper tolerance and to determine how they might be used in weed management programs in New Mexico.
Impacts
A weed garden was established and planted with species common to the irrigation canals as well as weed species common to production fields. The weed garden was used as an educational aid at a weed science field day, Water Hogs: Weed Science Field Day, where topics and demonstrations included weed identification, water use by weeds, rooting characteristics of weeds, and spectral characteristics of soil and plants. The research on the impact of soil fertility on the nutsedge-southern root-knot nematode interaction has implications for management of concurrent populations of these species in production fields. The research to determine response of chile pepper to herbicides will provide information to both the IR4 program on potential registrations and to New Mexico growers about how to safely use the products.
Publications
- Thomas, S. H., J. Schroeder, and L. Murray. 2004. Cyperus tubers protect Meloidogyne incognita from 1,3-dichloropropene. Journal of Nematology 36(2):131-136.
- Schroeder, J. S. H. Thomas, and L. W. Murray. 2004. Root-knot nematodes affect annual and perennial weed interactions with chile pepper. Weed Science 52:28-46.
- Schroeder, J., S. H. Thomas, C. Fiore, J. M. Fuchs, I. Ray, and L. W. Murray. 2004. Alfalfa suppresses concomitant populations of nutsedges and root-knot nematode in a subsequent pepper crop. Abstracts, Weed Science Society of America 44:128.
- Fiore, C., J. Schroeder, R. Sanderson, A. Ulery, L. Murray, L. DeMouche, and S. Schuster. 2004. Can soil characteristics be used to predict weed species along the irrigation canals in southern New Mexico. Proceedings, Western Society of Weed Science 57:36-37.
- Greenfield, B. J. Schroeder, S. H. Thomas, and L. W. Murray. 2004. The effect of nitrogen and potassium levels on the relationship between purple and yellow nutsedges and southern root-knot nematode. Proceedings, Western Society of Weed Science 57:40.
- Schuster, S., D. Cowley, C. Fiore, L. Murray, and J. Schroeder. 2004. Are weed species associated with crayfish habitat along the irrigation canals? Proceedings, Western Society of Weed Science 57:37.
- Wang, K., L. W. Murray, J. Schroeder, and S. H. Thomas. 2004. Techniques of topological analysis for examining purple and yellow nutsedge root architecture. Proceedings, Western Society of Weed Science 57:43-44.
- Fiore, Cheryl. 2004. A sustainable approach to nematode and nutsedge management in chile using nematode-resistant alfalfa as a rotational crop. M.S. thesis, Department of Entomology, Plant Pathology and Weed Science, New Mexico State University.
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Progress 01/01/03 to 12/31/03
Outputs
Chile pepper were planted in 2002 and 2003 to compare the efficacy of a prior three year rotation in southern root-knot nematode (RKN) resistant- or susceptible-alfalfa to cotton (with 1,3-D treatment) for suppression of RKN and yellow (YNS) and purple nutsedge (PNS). Both nutsedge species were suppressed for much of the growing season in plots rotated from alfalfa. At harvest, RKN populations in plots rotated from the RKN-resistant alfalfa were comparable to the 1,3-D treated plots and lower than the plots rotated from the RKN susceptible alfalfa. Chile yield was two times greater in plots rotated from alfalfa. Additional studies evaluated chile tolerance to and weed control with a number of candidate herbicides including pyrithiobac and oxyfluorfen. Research to determine best purple nutsedge management using halosulfuron and tillage found that PNS was effectively controlled at low rates of herbicide application when cultivation was used. In addition, RKN did not
affect halosulfuron efficacy on PNS. A project to map dominant herbaceous vegetation along the irrigation canals, laterals and sublaterals in southern New Mexico was initiated. Nearly two hundred of three hundred planned samples were obtained by the end of 2003. Sampling locations were randomly selected and GPS coordinants obtained. Data obtained at each location included percent vegetation cover, the five dominant plant species and percent cover of each species, depth of the water and canal, angle of the canal bank, spectral reflectance, and a composite soil sample that will be analyzed for texture, organic matter content, pH, salinity and SAR. Water use studies were initiated in the greenhouse to rank the water use of the dominant species found along the canal banks. Initial data indicate that bermudagrass and horsetail were the dominant species on the major canals. In addition, soil salinity was very high at some sampling points. Crayfish burrows were mapped at selected sampling
points in 2003. Initial data indicates that the burrows were more common in locations dominated by bermudagrass and may affect canal bank erosion. The data will be mapped using GIS software. Sampling and water use studies will continue in 2003.
Impacts
The rotation study has shown that both RKN and nutsedges can be managed for at least in chile pepper with crop rotation and without an additional fumigation treatment. Further work is needed to deliver this technology to producer groups and to determine how the alfalfa rotation impacts the RKN populations. Halosulfuron was been labeled for use as a postemergence-directed herbicide treatment in chile pepper in 2003. The research data collected under this project contributed to the decision to register this product in pepper.
Publications
- Schroeder, J., R. Sanderson, and A. Ulery. 2003. Weeds: an Indicator of Soil and Water Salinity and Water Loss along the Irrigation Canals. In Rossana Sallenave (ed.) Water Task Force Publication No. 1. New Mexico State University College of Agriculture and Home Economics.
- Luna, E., J. Schroeder, S. H. Thomas and L. W. Murray. 2003. Purple nutsedge growth and biomass partitioning in response to root-knot nematodes. Proceedings, Western Society of Weed Science 56: 36.
- Greenfield, B. J., J. Schroeder, S. H. Thomas, and L.W. Murray. 2003. Root-knot nematodes and tuber size affect early season growth of purple and yellow nutsedges. Proceedings, Western Society of Weed Science 56: 92.
- Fiore, C., L W. Murray, I. Ray, J. Schroeder and S. H. Thomas. 2003. Chile response to rotational crops for nutsedge and nematode suppression. Proceedings, Western Society of Weed Science 56: 60.
- Rosson, J., O. Elsebai, and R. Sanderson. 2003. Mapping the vegetation distribution along the irrigation system in the Mesilla Valley. Proceedings, Western Society of Weed Science 56:60.
- Schroeder, J. and P.A. Banks. 2003. Herbicide injury. In Pernezny, K., P. Roberts, J. Murphy, and N. Goldberg, editors. Compendium on Pepper Diseases. APS Press, St. Paul, MN. P. 56-57.
- Norworthy, J. 2003. Sustainable management of purple nutsedge and root-knot nematodes in chile pepper. M.S. thesis. Department of Entomology, Plant Pathology, and Weed Science, New Mexico State University.
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Progress 01/01/02 to 12/31/02
Outputs
Research for objective 1.3 was continued in 2002. The growth and development of yellow and purple nutsedge growing alone or together in the presence or absence of root-knot nematodes was determined using field microplots. Two nutsedge tubers were established per microplot in 2000 and data were taken through 2002. Through 2001, nutsedge shoot, root, rhizome and tuber production decreased in microplots containing root-knot nematode, contradicting data obtained in field microplot studies from 1994 through 1997. The effect of root-knot nematodes on the nutsedge may be affected by fertility (plots were only fertilized once a year) lack of annual plant hosts for the nematodes, or a change in the nematode population when a single perennial host was present. In 2002, microplots were fertilized regularly to determine if nutsedge and nematode populations would recover. Observations indicated that nutsedge populations recovered although not to the level of the noninfested plots.
Final biomass, tuber and root-knot population data were taken in October and data analysis is incomplete at this time. Research in objective 1.1 and 1.4 was continued to determine the influence of nematodes and chile peppers on root and rhizome architecture of yellow and purple nutsedge. Data analysis is in-progress. Studies were also repeated under objective 2 to determine the influence of nutsedges on the life cycle and virulence of root-knot nematode compared to chile. Detailed studies were conducted to determine the average number of eggs produced per egg mass and the number of egg masses produced after inoculation of the different plant species with eggs from each host plant. Initial analysis indicates that inoculum source affects the ability of the nematode to invade the host plant and host plant affects egg production as measured by number of eggs per egg mass. Life cycle of the nematode also appeared to be influenced by host plant combinations. The data analysis for the second
set of experiments must be completed before final conclusions are drawn.
Impacts
Biologically-based pest management will potentially reduce the amount of pesticides used in production fields. Effective pest management will decrease water use for chile production as well.
Publications
- Banks, P. A. and J. Schroeder. 2002. Carrier volume affects herbicide activity in simulated drift studies. Weed Technology 16(4).
- Schroeder, J., C. Fiore, I. Ray, S.H. Thomas and L.W. Murray. 2002. Yellow and purple nutsedge population response to crop management in root-knot nematode infested fields. Weed Science Society of America, Abstracts 42:55.
- Greenfield, B.J., J. Schroeder, S. Thomas, L.W. Murray, J. Fuchs. 2002. The effect of Meloidogyne incognita on purple nutsedge and yellow nutsedge inter- and intra-specific competition. Proceedings Western Society of Weed Science 55:94.
- Norsworthy, J., Schroeder, J., P.A. Banks, and L. W. Murray. 2002. Halosulfuron for purple nutsedge management in chile. Proceedings Western Society of Weed Science 55:31.
- Fiore, C., L. Murray, I. Ray, J. Schroeder, and S.H. Thomas. 2002. A sustainable approach to nematode and nutsedge management in chile using nematode resistant alfalfa as a rotation crop. Proceedings Western Society of Weed Science 55:93.
- Luna, E. L., J. Schroeder, C. Fiore, D. Coolidge. 2002. The effects of root-knot nematodes on the growth and development of purple nutsedge. Proceedings Western Society of Weed Science 55:9.
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