Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-28T16:08:41.720Z Has data issue: false hasContentIssue false

White Clover (Trifolium repens) Control and Flower Head Suppression in Apple Orchards

Published online by Cambridge University Press:  20 January 2017

Andrew W. MacRae
Affiliation:
North Carolina State University, P.O. Box 7609, Raleigh, NC 27695
Wayne E. Mitchem*
Affiliation:
North Carolina State University, P.O. Box 7609, Raleigh, NC 27695
David W. Monks
Affiliation:
North Carolina State University, P.O. Box 7609, Raleigh, NC 27695
Michael L. Parker
Affiliation:
North Carolina State University, P.O. Box 7609, Raleigh, NC 27695
*
Corresponding author's E-mail: wayne_mitchem@ncsu.edu

Abstract

White clover is a weed in apple orchards that competes with the crop; also, flowers of this weed are unwanted attractants of honey bees at times when insecticides, which are harmful to these pollinators, are being applied. In 1997 and 1998, white clover flower head and plant control by clopyralid alone and with 2,4-D and apple tolerance to these herbicides were determined. Treatments consisted of clopyralid at 0.10 and 0.21 kg ae/ha, 2,4-D at 1.1 kg ae/ha, and 2,4-D at 1.1 kg ae/ha plus 0.03 or 0.05 kg ae/ha clopyralid, which were applied 2 wk before full apple bloom and 2 wk after full apple bloom, and a nontreated check. No crop injury occurred with any treatment. All herbicide treatments provided some white clover control and flower head suppression. No differences in white clover bloom reduction were observed through May among treatments containing clopyralid. As summer progressed, the effect of clopyralid rate became more apparent. Clopyralid at 0.21, regardless of application time, provided 99% vegetative control and 100% flower head reduction through July. Clopyralid plus 2,4-D controlled white clover better than 2,4-D alone. However, vegetative control and flower head reduction with clopyralid at reduced rates (0.03 or 0.05 kg ae/ha) plus 2,4-D were not acceptable (76% or less and 78% or less, respectively). Thus, clopyralid at 0.10 and 0.21 kg ae/ha will be necessary for acceptable white clover vegetation control and flower head reduction.

Type
Research Article
Copyright
Copyright © 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

Literature Cited

Anderson, J. F. and Glowa, W. 1984. Insecticidal poisoning of honey bees in Connecticut. Environ. Entomol. 15:7074.Google Scholar
Anonymous. 2004. Stinger product label. Dow AgroSciences L.L.C. Indianapolis, IN: Dow AgroSciences. 1 p.Google Scholar
Boelter, A. M. and Wilson, W. T. 1984. Effect of methyl parathion vapors from contaminated pollen on honey bees (Hymenoptera: Apidae) within a hive. Environ. Entomol. 13:12331236.Google Scholar
Johansen, C. A. and Brown, F. C. 1972. Toxicity of carbaryl-contaminated pollen collected by honey bees. Environ. Entomol. 1:385386.Google Scholar
Jones, A. L. and Sutton, T. B. 1996. Diseases of tree fruits in the east. Michigan State University Bull. NCR 45:51.Google Scholar
McVay, J. R., Walgenbach, J. F., Sikora, E. J., and Sutton, T. B. 1994. A growers guide to apple insects and diseases in the southeast. North Carolina State University, North Carolina Cooperative Extension Cir. AG-572. Raleigh, NC: College of Agriculture and Life Sciences. Pp. 6263.Google Scholar
Mitchem, W. E. and Monks, D. W. 2004. Chemical Weed Control in Fruit Crops. 2004 North Carolina Agricultural Chemical Manual: Web page: http://ipm.ncsu.edu/agchem/agchem.html. Accessed: September 1, 2004.Google Scholar
Neal, J. C. 1990. Non-phenoxy herbicides for perennial broadleaf weed control in cool-season turf. Weed Technol. 4:555559.Google Scholar
Neal, J. C. and Mascianica, M. R. 1988. Phenoxy and non-phenoxy herbicides for controlling dandelion, plantain, clover, and veronica. Proc. Northeast. Weed Sci. Soc. 42:183184.Google Scholar
Olson, B. D. and Hall, A. B. 1988. Postemergence broadleaf weed control in turf with non-phenoxy herbicide combinations. Proc. Northeast. Weed Sci. Soc. 42:185186.Google Scholar
Olson, B. D. and Mackasey, M. M. 1989. Control of broadleaf weeds in turf with clopyralid and triclopyr combinations. Proc. Northeast. Weed Sci. Soc. 43:105106.Google Scholar
[SAS] Statistical Analysis Systems. 1989. The SAS System for Windows Version 6.12. Cary, NC: Statistical Analysis Systems Institute. 1028 p.Google Scholar
Stanghellini, M. S. 2003. Relative toxicity of pesticides to honey bees. in Toth, S. J., ed. 2003 North Carolina Agricultural Chemicals Manual. AG-1. Raleigh, NC: College of Agriculture and Life Sciences. Pp. 5861.Google Scholar
Uva, R. H., Neal, J. C., and DiTomaso, J. M. 1997. Weeds of the Northeast. Ithaca, NY: Cornell University Press. P. 236.Google Scholar