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Seed Germination and Seedling Emergence of Scotch Broom (Cytisus scoparius)

Published online by Cambridge University Press:  20 January 2017

Timothy B. Harrington*
Affiliation:
USDA Forest Service, Pacific Northwest Research Station, 3625 93rd Avenue Southwest, Olympia, WA 98512
*
Corresponding author's E-mail: tharrington@fs.fed.us

Abstract

Scotch broom is a large, leguminous shrub that has invaded 27 U.S. states. The species produces seeds with a hard coat that remain viable in the soil for years. Growth-chamber studies were conducted to determine effects of temperature regime and cold-stratification period on seed germination. Seedling emergence, mortality, and biomass also were studied in response to sulfometuron and metsulfuron herbicides and variation in soil texture and watering regime. Germination was greatest for a dark/light temperature regime of 15/20 C. Initial rates of germination increased as stratification period was varied from 0 to 60 d, but final germination after 90 d did not differ significantly among periods. Applied alone or in combination, sulfometuron and metsulfuron decreased biomass and increased mortality of seedlings. Mortality from simulated soil drought was greater in the presence versus absence of sulfometuron (20 and 6% mortality, respectively) probably because the herbicide reduced root biomass by 58 to 95%. Invasiveness of Scotch broom is facilitated by a prolonged period of germination across a broad temperature range. Increased control of Scotch broom seedlings with sulfometuron is likely if application is timed to expose recently emerged seedlings to developing conditions of soil drought.

Type
Weed Biology and Ecology
Copyright
Copyright © Weed Science Society of America 

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References

Literature Cited

Abdallah, M. M. F., Jones, R. A., and El-Beltagy, A. S. 1989. An efficient method to overcome seed dormancy in Scotch broom (Cytisus scoparius). Environ. Exp. Bot. 29:499505.Google Scholar
Ahrens, W. H. 1994. Herbicide Handbook. 7th ed. Champaign, IL Weed Science Society of America. 274276.Google Scholar
Blair, M. P. and Zedaker, S. M. 2005. Evaluation of clopyralid, fluroxypyr, metsulfuron methyl, and triclopyr for Scotchbroom control. In. Proceedings of the 7th Annual Meeting of Southeast Exotic Pest Plant Council. Birmingham, AL. http://www.se-eppc.org/2005/evaluationposter.cfm Accessed: April 27, 2009.Google Scholar
Bossard, C. C. 1993. Seed germination in the exotic shrub Cytisus scoparius (Scotch broom) in California. Madroño. 40:4761.Google Scholar
Bossard, C. C. and Rejmánek, M. 1994. Herbivory, growth, seed production, and resprouting of an exotic invasive shrub, Cytisus scoparius . Biol. Conserv. 67:193200.Google Scholar
Gilkey, H. M. 1957. Weeds of the Pacific Northwest. Corvallis, OR Oregon State College. 382.Google Scholar
Harrington, T. B. 2007. Establishment of Scotch broom seedlings in Douglas-fir forests: effects of overstory retention level and seedbed type. Pages 3742. in. Meeting the Challenge: Invasive Plants in Pacific Northwest Ecosystems, Gen. Tech. Rep. PNW-GTR-694. Seattle, WA USDA Forest Service, Pacific Northwest Research Station. 166.CrossRefGoogle Scholar
Ketchum, J. S. and Rose, R. 2003. Preventing establishment of exotic shrubs (Cytisus scoparius (L.) Link. and Cytisus striatus (Hill)) with soil active herbicides (hexazinone, sulfometuron, and metsulfuron). New For. 25:8392.CrossRefGoogle Scholar
Larsen, S. U. and Bibby, B. M. 2005. Differences in thermal time requirement for germination of three turfgrass species. Crop Sci. 45:20302037.CrossRefGoogle Scholar
Quinn, G. P. and Keough, M. J. 2002. Experimental design and data analysis for biologists. Cambridge, UK Cambridge University Press. 4950.CrossRefGoogle Scholar
Sheppard, A. W., Hodge, P., Paynter, Q., and Rees, M. 2002. Factors affecting invasion and persistence of broom Cytisus scoparius in Australia. J. Appl. Ecol. 39:721734.Google Scholar
Sokal, R. R. and Rohlf, J. F. 1981. Biometry. 2nd ed. San Francisco, CA W.H. Freeman. 859.Google Scholar
[USDA NRCS] U. S. Department of Agriculture Natural Resources Conservation Service 2009. PLANTS Database, Scotch broom, Cytisus scoparius L. http://plants.usda.gov/java/profile?symbol=CYSC4. Accessed: April 10, 2009.Google Scholar
Wearne, L. J. and Morgan, J. W. 2004. Community-level changes in Australian subalpine vegetation following invasion by the non-native shrub Cytisus scoparius . J. Veg. Sci. 15:595604.Google Scholar
Williams, P. A. 1981. Aspects of the ecology of broom (Cytisus scoparius) in Canterbury, New Zealand. N. Z. J. Bot. 19:3143.CrossRefGoogle Scholar
Young, J. A. and Young, C. G. 1992. Seeds of woody plants in North America. Portland, OR Dioscorides. 131.Google Scholar