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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #191297
Title: CRITICAL PERIOD OF TROPICAL SPIDERWORT (COMMELINA BENGHALENSIS) CONTROL IN COTTON

Author
item Webster, Theodore
item GREY, T - UNIVERSITY OF GEORGIA
item FLANDERS, J - UNIVERSITY OF GEORGIA
item CULPEPPER, A - UNIVERSITY OF GEORGIA

Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 1/12/2006
Publication Date: 2/13/2006
Citation: Webster, T.M., Grey, T.L., Flanders, J.T., Culpepper, A.S. 2006. Critical period of Tropical spiderwort (Commelina benghalensis) control in cotton [abstract]. Weed Science Society of America Abstracts. p. 80.

Interpretive Summary:

Technical Abstract: Tropical spiderwort, or Benghal dayflower, is an exotic invasive weed that has recently become the most troublesome cotton weed in GA and FL. The objective of this study was to evaluate the critical period during the growing season that cotton must be kept free of spiderwort in order to avert a significant yield loss (>5%). Studies were conducted in 2003, 2004, and 2005 on a grower’s farm with a naturalized spiderwort population in Grady County, GA. There was a single planting date in 2003, but there were two planting dates in 2004 and 2005, representing early-planted cotton (May) and late-planted cotton (4 to 6 weeks later). Cotton yield was reduced up to 45% by season long interference with spiderwort. The critical period of weed control varied with cotton planting date. In 2003, the critical period of spiderwort control was between 3 and 6 weeks after planting (WAP). In May-planted cotton in 2004, removal of spiderwort was necessary at 6 WAP. There was substantial cotton growth prior to spiderwort establishment in 2004 early-planted cotton. Maximum yield loss was 20% from May 2004-planted cotton. In contrast, the critical period of weed control for June 2004-planted cotton was between 2 and 8 WAP. In June-planted cotton, spiderwort and cotton emerged simultaneously, allowing spiderwort to interfere with cotton earlier in the growing season. In conclusion, cotton yield loss from spiderwort interference can be minimized by planting cotton early in the growing season, prior to substantial spiderwort emergence.