Commelina benghalensis (herb)

Ecology Distribution Management Info Impact Info References and Links Contacts

Management Information Preventative measures: Preventing dense populations of Commelina benghalensis from establishing in agricultural areas helps avoid the accumulation of large seed banks. Cultivation of a cover crop can be used to smother emerging and established populations of C. benghalensis, however mechanical or chemical removal may be needed prior to planting the cover crop. Increasing the density of plants in soybeans and doubling rows in corn helps control and shade out C. benghalensis (Flanders, 2007; NAPPO, 2003; Prostko, 2005). Physical: Removal by pulling or use of a tool such as a hoe, or mechanical cultivation have a varying, but usually low, degree of success due to the regenerative properties of C. benghalensis. In one study, comparing conventional tillage to strip tillage, conventional tillage was shown to have a much lower density (3 plants/m2 versus 60 plants/m2) of C. benghalensis in a weed count performed after peanuts and cotton were planted (Brecke, 2007; NAPPO, 2003). Chemical: The use of herbicides with residual activity to combat C. benghalensis is often most effective because of the weed's ability to germinate through out the growing season. C. benghalensis is resistant to glyphosphate in "Roundup Ready" cotton . In one study, adding metachlor to the first glyphosphate application increased control to 96% under conventional tillage and 75% under strip tillage with 50% soil disturbance. According to Prostko (2005), "Dual Magnum" is the most effective residual herbicide to control C. benghalensis in cotton crops. Prostko also suggests "Dual Magnum" application in peanuts for successful suppression, especially if at least 0.5 inches of rain or irrigation is received within 7-10 days. Early post-emergence applications of herbicide should be performed before seedlings of C. benghalensis reach 3-4 inches (Brecke, 2007; Flanders, 2007). Integrated management: Pieces of cut stems of C. benghalensis, usually cut during physical eradication or cultivation, have the ability to survive a short period of drought stress and resprout. Stem segments must desiccate to a moisture content of 50% for a period of 30 days to reach a 0% regeneration rate, however the size of the stem segment may lengthen the period of viability (Grey, 2007).              Location Specific Management Information Alabama Commelina benghalensis is listed as a 'Class A noxious weed' in Alabama (USDA NRCS 2008). California Commelina benghalensis is listed as a 'Quarantine pest' in California (USDA NRCS 2008). Florida (USA) Commelina benghalensis is listed as a 'Noxious weed' in Florida (USDA NRCS 2008). North Carolina Commelina benghalensis is listed as a 'Class A noxious weed' in North Carolina (USDA NRCS 2008). United States (USA) Commelina benghalensis is listed as: a 'Noxious weed' in the USA; a 'Prohibited' weed in Massachusetts; a 'Prohibited noxious weed' in Minnesota; a 'Quarantine' pest in Oregon; a 'Plant pest' in South Carolina and a 'Class A Noxious weed' in Vermont (USDA NRCS 2008).          Management Resources/Links 1. Brecke, B.J. and Hutto, K.C. and Stephenson, D.O. IV, 2007. Impact of Tillage and Hervicides on Tropical Spiderwort. University of Florida, West Florida Research and Education Center. Volume 38, pp. 83. The American Peanut Research and Education Society, Inc.         Summary: This article is found in a volume which is a collection of publications, mainly abstracts and technical summaries, presented at a meeting held by the American Peanut Research and Education Society Incorporated in 2006. Available from: http://www.apres.okstate.edu/old%20proceedings/Vol%2038%20Proc.pdf [Accessed 30 April 2008] 2. Maddox, V. and Byrd, J.D. and Westbrooks, R., 2006. Invasive Species Fact Sheet: Benghal dayflower. The GeoResources Institute in cooperation with the United States Geological Survey and the Extension Service at Mississippi State University.         Summary: This publication is a concise fact sheet on Benghal dayflower, otherwise known as Commelina benghalensis. Available from: http://www.gri.msstate.edu/lwa/invspec/tropical_spiderwort.pdf [Accessed 30 April 2008] 3. North American Plant Protection Organization (NAPPO), 2003. Pest Risk Assessment, Grains Panel Pest Facts Sheet: Commelina benghalensis L.         Summary: This fact sheet is a very informative overview of the species Commelina benghalensis including distribution, biology, identification, economic impact, and management information. Available from: http://www.nappo.org/PRA-sheets/Commelinabenghalensis.pdf [Accessed 30 April 2008] 4. Prostko, E.P. and Culpepper, A.S. and Webster, T.M. and Flanders, J.T., 2005. Tropical Spiderwort Identification and Control in Georgia Field Crops. Circular 884, Cooperative Extension Service, The University of Georgia College of Agricultural and Environmental Sciences.         Summary: This publication is an excellent source for identification of Commelina benghalensis and for control pertaining to the cultivation of certain crops grown in the United States. Available from: http://www.gainvasives.org/pubs/C884.pdf [Accessed 30 April 2008] 5. USDA, NRCS. 2008. Commelina benghalensis The PLANTS Database (http://plants.usda.gov, 29 April 2008). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.         Summary: Available from: http://plants.usda.gov/java/profile?symbol=COBE2 [Accessed 30 April 2008] 6. Varnham, K. 2006. Non-native species in UK Overseas Territories: a review. JNCC Report 372. Peterborough: United Kingdom.         Summary: This database compiles information on alien species from British Overseas Territories. Available from: http://www.jncc.gov.uk/page-3660 [Accessed 10 November 2009] 7. Webster, T.M. and Burton, M.G. and Culpepper, A.S. and York, A.C. and Prostko, E.P., 2005. Tropical Spiderwort (Commelina benghalensis): A Tropical Invader Threatens Agroecosystems of the Southern United States. Weed Technology: Volume 19:501-508, 2005.         Summary: This article is an excellent source for the identification and control of Commelina benghalensis in the United States. Available from: http://www.ars.usda.gov/sp2UserFiles/person/5963/PDF/2005%20WT%2019-501-508%20Weed%20Alert.pdf [Accessed 30 April 2008]          Results Page: 1