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Recent and Current Research Projects

Ecology and management of Japanese Stiltgrass (Microstegium vimineum). Studies included evaluations of preemergence and postemergence herbicide efficacy, seed dormancy and germination requirements, and native plant community responses to Japanese stiltgrass control options. Project conducted as a Ph.D. project by Dr. Caren Judge. Summary of field results presented at the 2005 Weed Science Society of America annual conference. Click here for the powerpoint presentation. Dissertation is available here.

An assessement protocol for Invasive species currently sold in the nursery trade is being developed by Ms. Clara Englert as part of her M.S. project. This project was funded by a grant from the North Carolina Nursery and Landscape Association. Dr. Thomas Ranney is co-advisor on this project. Thesis is available here.

Longevity of weed control in container nursery crops. Using bioassay methods we have shown that preemergence herbicides applied to nursery crops provide only 4 to 6 weeks control of most weeds. Typical re-application intervals of 8 to 12 weeks will allow weeds to emerge and establish. This research has been supported by grants from the Horticultural Research Institute, BASF Corporation and Valent Corporation. Publications: trifluralin dissipation; Longevity of PRE herbicides; Freehand residual control.

Control options for recently introduced weeds in nursery crops. A collaborative project with Dr. Jeff Derr, Virginia Tech University. The efficacy of herbicides labeled for preemergence weed control in container nurseries was compared on several species of newly introduced weeds. This project is supported by a grant from the Horticultural Research Institute.

Dodder host specificity in bedding plants. Currently few control options are available to landscape managers who have landscape beds infested with dodder (Cuscuta spp.). This study identified several bedding plant species that were not preferred hosts of dodder, providing a potential management strategy for this parasitic weed. Project was supported in 2005 by a grant from the NC Extension IPM Program. Recent results presented at the Southern Nursery Association Research Conference -- click here for a powerpoint presentation.

Innovative and Environmentally Responsible Control of Woody Vegetation on Rights of Ways. In collaboration with Dr. Jim Burton, Department of Horticultural Science. The effectiveness of herbicides applied through wet-blade mower technologies is compared with conventional mowing and spraying techniques. This project was funded by a grant from the NC Department of Transportation.

Herbicide Safety on Nursery Crops and Landscape Ornamentals. Rearch collaborations with the USDA-IR-4 program and product manufacturers continues to expand herbicide registrations and register new herbicides for weed control in ornamentals. Recent foci of the program have been the development of flumioxazin (Broadstar and SureGuard) and dimethenamid-p (Tower) for weed control in nursery crops; herbicide safety in herbaceous perennials; herbicide safety in ferns; and safety of postemergence herbicides for nutsedge and broadleaf weed control in ornamentals.

Taxonomy and management of common weeds of nursery crops. Several projects include a comparison of Ranunculus ficaria sub species distribution and spread in the U.S.(manuscript in review); and a taxonomic study of species of Cardamine species found in container nursery crops. Both projects conducted by Ms. Angela Post.

Extension Program

Weed management systems for nursery crops, landscapes, and Christmas trees. Programs emphasize in-service training of Extension field faculty and resource development.

Books and Bulletins:

Weeds of the Northeast -- a full color guide to ~300 weeds. Published by Cornell University Press
Weeds of Container Nurseries -- a 16 page color bulletin published by the North Carolina Association of Nurserymen. On-line version here.
Weed Control Suggestions for Christmas Trees, Woody Ornamentals and Flowers; NCSU Extenstion Publication AG-427. Currently out of print and being revised.
BMP's for Field Production of Nursery Crops -- on-line

Horticulture Information Leaflets:

Greenhouse weed control -- HIL 570
Weed control in color beds -- HIL 644
Weed control in conifer seedbeds and landscape beds -- HIL 449
Non-selective Herbicides for Nursery and Landscapes -- HIL 648
Controlling Sedges in Landscape Plantings -- HIL 647
Japanese Stiltgrass control -- HIL 905

Complete Publication List

Selected Publications

Zhou, T. and J. C. Neal. 1995. Annual bluegrass (Poa annua) control with Xanthomonas campestris pv. poannua in New York State. Weed Technology 9:173-177.
Uva, R. H., J. C. Neal and J. M. DiTomaso. 1997. Weeds of the Northeast. Cornell University Press, New York. 396pp.
Neal, J. C., J. F. Derr, A. F. Senesac and W. A. Skroch, 1999. Weed Control Suggestions for Christmas Trees, Woody Ornamentals, and Flowers. NC Cooperative Extension publication AG-427.
Neal, J. C. 2000. Weed control in woody liner production. Proceedings of the International Plant Propagator's Soc. 50:528-531.
Krings, A. and J. C. Neal. 2001. A Scutellaria (Lamiaceae) new to North Carolina and a key to the small-flowered Carolina congeners. SIDA 19(3):735-739.
Judge, C. A., J. C. Neal, and R. B. Leidy. 2003. Trifluralin (Preen) dissipation from the surface layer of a soilless plant growth substrate. Journal of Environmental Horticulture 21:216-222 pdf
Judge, C. A., J. C. Neal, and J. B. Weber. 2004. Dose and concentration responses of common nursery weeds to Gallery, Surflan and Treflan. Journal of Environmental Horticulture 22:106-112. pdf
Judge, C. A., J. C. Neal. and J.F. Derr. 2005. Response of Japanese Stiltgrass (Microstegium vimineum) to application timing, rate, and frequency of postemergence herbicides. Weed Technol. 19:912-917. pdf
Neal, J. C. and J. F. Derr. 2005. Weeds of container nurseries in the United States. NC Nurserymen’s Assoc. 16 p.
Judge,C. A. and J. C. Neal. 2006. Early postemergence control of nursery weeds with Broadstar, OH2 and Snapshot TG. J. Environ. Hort 24(2):105-108 pdf
Post, A. R., A. Krings, W. Wall, and J. C. Neal. 2009. Introduced lesser celandine (Ranunculus ficaria, Ranunculaceae) and its putative subspecies in the United States: a morphometric analysis. J. Bot. Res. Inst. Texas (formerly SIDA) 3(1):193-209 pdf
Post, A.R., J. C. Neal, A. Krings, B. R. Sosinski, and Q. Xiang. 2009. New Zealand bittercress (Cardamine corymbosa; Brassicaceae): new to the United States. Weed Technol. 23:604-607. pdf
Walker, L.H., J.C. Neal and J.Derr. 2010. Preemergence control of doveweed (Murdannia nudiflora) in container grown nursery crops. J. Environ. Hort. 28(1):8-12 pdf


International Experience

Participant in the International Bioherbicide Group


Screening rhizobacteria for selective suppression of annual ryegrass in canola and wheat. Hosted by Dr. Gavin Ash, Charles Sturt University, Wagga Wagga, NSW, Australia.

Weed management practices in Australian nurseries. Hosted by Dr. Ian Gordon, Univ. of Queensland, Gatton, Queensland, Australia