Hostname: page-component-8448b6f56d-t5pn6 Total loading time: 0 Render date: 2024-04-24T14:24:33.193Z Has data issue: false hasContentIssue false
  • English
  • Français

Advances in Witchweed Control

Published online by Cambridge University Press:  12 June 2017

W. C. Shaw ,
D. R. Shepherd ,
E. L. Robinson  and
P. F. Sand
W. C. Shaw
Affiliation:
Crops Research Division, Agricultural Research Service, U. S. Department of Agriculture, Beltsville, Maryland and Whiteville, North Carolina
D. R. Shepherd
Affiliation:
Plant Pest Control Division, Agricultural Research Service, U. S. Department of Agriculture, Washington, D. C. and Whiteville, North Carolina
E. L. Robinson
Affiliation:
Crops Research Division, Agricultural Research Service, U. S. Department of Agriculture, Beltsville, Maryland and Whiteville, North Carolina
P. F. Sand
Affiliation:
Plant Pest Control Division, Agricultural Research Service, U. S. Department of Agriculture, Washington, D. C. and Whiteville, North Carolina
Get access

Abstract

Witchweed (Striga asiatica), a parasitic chlorophyll-bearing plant (Scrophuladiaceae) which attacks corn, sorghum, sugarcane, and more than 60 other important crop plants and weeds belonging to the grass family, was found in North Carolina and South Carolina in 1956. It presents a potential hazard to the production of grain crops with an annual value of more than 5 billion dollars in the United States. Continued extensive surveys indicate that witchweed is now present in 20 counties in North Carolina and 10 in South Carolina on a total of 9,566 farms containing 210,671 acres. Federal interstate and state intrastate quarantines (the first for a weed in the U. S.) were established to reduce its spread. Witchweed produces up to 500,000 microscopic longlived seeds per plant. These do not usually germinate until stimulated by a chemical stimulant secreted by the roots of certain plants. A stimulant has been isolated from corn but its exact chemical structure has not be determined. More than 300 chemicals have been evaluated in the laboratory in attempts to find a synthetic stimulant. Of these, 18 stimulated witchweed seed germination in the laboratory but they have not been evaluated for their effectiveness in controlling witchweed under field conditions. After 4 years of catch or trap crops, excellent control of witchweed has been obtained and highly profitable crops of corn have been produced on heavily infested land. Corn grown continuously with witchweed seed production prevented by 2,4-dichlorophenoxyacetic acid [2,4-D] has resulted in excellent witchweed control and high corn yields. Corn grown continuously receiving 2,3,6-trichlorophenylacetic acid [fenac] as a pre-planting soil-incorporated treatment and 2,4-D as a post-emergence spray as needed have proved effective full-season control of witchweed. Tobacco and certain other crops cannot be grown in rotation with corn for a period of 2 years after this treatment because of fenac residues in the soil. Other herbicides as pre-planting soil-incorporated or premergence treatments to control broadleaved and grass-type weeds plus 2,4-D to prevent witchweed seed production have been highly effective combinations for witchweed control. Quick eradication of witchweed will not be easy but effective control now and future eradication look favorable.

Type
Research Article
Information
Weeds , Volume 10 , Issue 3 , July 1962 , pp. 182 - 192
Copyright
Copyright © 1962 Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Selected Sources

1. Brown, R., and Edwards, M. 1944, 1946. The germination of the seeds of Striga lutea. I. Host influence and the progress of germination. Ann Bot., N. S. 8–131–148. II. The effect of time of treatment and of concentration of the host stimulant. Ann. Bot., N. S., 10–133–142.CrossRefGoogle Scholar
2. Dowler, C. C., Egley, G. H., Kust, C. A., and Sand, P. F. 1959–1960. Witchweed investigations, Witchweed Laboratory, Whiteville, N. C. Annual Reports, Plant Pest Control Division, Agricultural Research Service, U. S. Department of Agriculture, Beltsville, Md. Unpublished data.Google Scholar
3. Garriss, Howard R., and Wells, J. C. 1956. Parasitic herbaceous annual associated with corn disease in North Carolina. Plant Disease Reporter 40:837–838.Google Scholar
4. McGrath, Hilde, Shaw, W. C., Jansen, L. L., Lipscomb, B. R., Miller, P. F., and Ennis, W. B. 1957. Witchweed (Striga asiatica), a new parasitic plant in the United States. Special Publication No. 10, 142 pages. Issued by Crops Research Division, Agricultural Research Service, U. S. Department of Agriculture, Beltsville, Md. Google Scholar
5. Nelson, R. R. 1957. Studies on the witchweed parasite of corn. Proceedings 12th American Seed Trade Meeting, pp. 19–25, Chicago, I11. Google Scholar
6. Nelson, R. R. 1958. Preliminary studies on the host range of Striga asiatica . Plant Disease Reporter 42 (3):376–382.Google Scholar
7. Nelson, R. R. 1958. The effect of soil type and temperature on the growth and development of witchweed (Striga asiatica) under controlled soil temperatures. Plant Disease Reporter 42(1):152–155.Google Scholar
8. Nelson, R. R. 1958. Preliminary studies on the Striga parasitic weed of corn. Plant Disease Reporter 41 (5): 14–15.Google Scholar
9. Robinson, E. L. 1958. Seeks control for witchweed—progress report. What's New in Crops and Soils 10 (8):14–15.Google Scholar
10. Robinson, E. L. 1961. Soil-incorporated pre-planting herbicides for witchweed control. Weeds 9:411–415.CrossRefGoogle Scholar
11. Robinson, E. L. and Dowler, Clyde C. 1961. Herbicides for the control of witchweed (Striga asiatica) in early and late planted corn. Weeds 9:522–526.CrossRefGoogle Scholar
12. Robinson, E. L. and Stokes, I. E. 1960. Witchweed: A potential pest of sugarcane in the United States. The Sugar Journal. Google Scholar
13. Robinson, E. L. 1957, 1958, 1959, 1960. Witchweed investigations, Witchweed Laboratory, Whiteville, N. C. Annual Reports. Crops Research Division, Agricultural Research Service, U. S. Department of Agriculture, Beltsville, Md. Unpublished data.Google Scholar
14. Robinson, E. L. 1960. Growth of witchweed (Striga asiatica) as affected by soil types and soil and air temperatures. Weeds 8:576–581.CrossRefGoogle Scholar
14a. Rogers, W. E., and Nelson, R. R. 1961. Studies on the penetration and nutrition of Striga asiatica . Phytopathology: (In press).Google Scholar
15. Saunders, A. R. 1933. Studies on phanerogramic parasitism with particular reference to Striga lutea . South African Dept. of Agr. Science Bull. 128.Google Scholar
16. Wilson Jones, K. 1957. The genus Striga—a study in plant parasitism and its control. Preliminary draft of a monograph supplied to the atuhors as a private communication.Google Scholar
17. Wilson Jones, K. 1953. Further experiments on witchweed control I. The effect of hormone weed-killer applications at different rates and times on irrigated dura (grain sorghum). Empire J. of Exper. Agr. 21 (84):331–339.Google Scholar
18. Wilson Jones, K. 1953. Further experiments on witchweed control II. The existence of physiological strains of Striga hermonthica . Empire Journal of Exper. Agr. 23 (92–92):206–214.Google Scholar
19. Witchweed quarantine and regulations (Proposed). Federal Register, 1957, pp. 4914–4918. Effective September 6, 1957. Revised—Federal Register, 1959, pp. 4296–4303.Google Scholar
20. Witchweed infestation surveys. 1956–1961. Plant Pest Control Division, Agricultural Research Service, U. S. Department of Agriculture, Washington, D. C. Unpublished data.Google Scholar
21. Worsham, A. D. 1961. Germination of Striga asiatica (L.) Kuntze (witchweed) seed and studies on the chemical nature of the germination stimulant. A. Ph.D. Thesis, 112 pages, Department of Field Crops, North Carolina State College, Raleigh, N. C. Google Scholar
22. Worsham, A. D., Moreland, D. E., and Klingman, G. C. 1959. Stimulation of Striga asiatica (witchweed) seed germination by 6-substituted purines. Science 130:1654–1656.CrossRefGoogle Scholar