Glyphosate Systems for Weed Control in Glyphosate-Tolerant Cotton (Gossypium hirsutum)1

Field studies were conducted at three locations in North Carolina to evaluate clomazone preemergence (PRE) in glyphosate-tolerant cotton. Cotton was injured by fluometuron PRE at one location. Clomazone PRE controlled common ragweed, goosegrass, large crabgrass, and prickly sida better than trifluralin preplant incorporated (PPI). Trifluralin controlled Palmer amaranth better than clomazone. The addition of a late post-directed (LAYBY) treatment of cyanazine plus MSMA improved the control of goosegrass. Glyphosate at 0.8 kg ai/ha, used postemergence as needed, controlled tall morningglory and entireleaf morningglory at least 84%. Common ragweed was controlled with all herbicides, except trifluralin PPI. Prickly sida was controlled 94% or greater in glyphosate-containing systems. Cotton yields and net returns were similar for all glyphosate systems, regardless of soil-applied herbicides and LAYBY treatment options. Nomenclature: Clomazone; cyanazine; fluometuron; glyphosate; MSMA; trifluralin; common ragweed, Ambrosia artemisiifolia L. #3 AMBEL; entireleaf morningglory, Ipomoea hederacea var. integriuscula Gray # IPOHG; goosegrass, Eleusine indica (L.) Gaertn. # ELEIN; large crabgrass, Digitaria sanguinalis (L.) Scop. # DIGSA; Palmer amaranth, Amaranthus palmeri S.Wats # AMAPA; prickly sida, Sida spinosa L. # SIDSP; tall morningglory, Ipomoea purpurea (L.) Roth # PHBPU; cotton, Gossypium hirsutum L. ‘Paymaster 1330RR’, ‘DP5415RR’. Additional index words: Economic analysis, herbicide-resistant crops. Abbreviations: ANS, as needed spray; DAP, days after planting; EPOST, early postemergence; fb, followed by; LAYBY, late post directed; POST, postemergence; POT, postemergence over-the-top; PPI, preplant incorporated; PRE, preemergence.

[1]  G. H. Scott,et al.  Economic evaluation of HADSS™ computer program for weed management in nontransgenic and transgenic cotton , 2001, Weed Science.

[2]  J. W. Wilcut,et al.  Weed management in bromoxynil-resistant Gossypium hirsutum , 1999, Weed Science.

[3]  J. Ruberson.  Handbook of Pest Management , 1999 .

[4]  S. Askew,et al.  Cost and Weed Management with Herbicide Programs in Glyphosate-Resistant Cotton (Gossypium hirsutum) , 1999, Weed Technology.

[5]  A. Culpepper,et al.  Weed Management and Net Returns With Transgenic, Herbicide-Resistant, and Nontransgenic Cotton (Gossypium hirsutum) , 1999, Weed Technology.

[6]  L. Mccarty,et al.  Fluctuating temperature and light influence seed germination of goosegrass (Eleusine indica) , 1997, Weed Science.

[7]  D. Jordan,et al.  Weed Management in Cotton (Gossypium hirsutum) with Soil-Applied and Post-Directed Herbicides , 1997, Weed Technology.

[8]  David L. Jordan,et al.  Influence of Application Variables on Efficacy of Glyphosate , 1997, Weed Technology.

[9]  J. Byrd.  Report of the 1989 cotton weed loss committee. , 1996 .

[10]  J. Toler,et al.  Chemical Control Systems for Coffee Senna (Cassia occidentalis) in Cotton (Gossypium hirsutum) , 1996, Weed Technology.

[11]  D. Jordan,et al.  Utility of Clomazone for Annual Grass and Broadleaf Weed Control in Peanut (Arachis hypogaea) , 1994, Weed Technology.

[12]  A. C. York,et al.  Clomazone as a Component in Cotton (Gossypium hirsutum) Herbicide Programs , 1993, Weed Technology.

[13]  A. C. York,et al.  Cotton (Gossypium hirsutum) Response to Clomazone and Insecticide Combinations , 1992, Weed Technology.

[14]  T. C. Mueller,et al.  Cotton (Gossypium hirsutum) Yield Response to Mechanical and Chemical Weed Control Systems , 1992, Weed Science.

[15]  D. L. Colvin,et al.  Cotton (Gossypium hirsutum) Yield Response to Cultivation Timing and Frequency , 1992, Weed Technology.

[16]  L. R. Oliver,et al.  Weed Control with Clomazone Alone and with Other Herbicides , 1989, Weed Technology.

[17]  G. Buchanan,et al.  Efficacy and Economics of Weed Control Methods in Cotton (Gossypium hirsutum) , 1984, Weed Science.

[18]  A. Galston.  Chemical weed control. , 1977, Science.

[19]  E. R. Burns,et al.  Influence of Weed Competition on Cotton , 1970, Weed Science.

[20]  R. F. Goudey.  Chemical Weed Control , 1946 .

[21]  Michael A. Jones,et al.  Tolerance of Transgenic Cotton to Topical Applications of Glyphosate , 1999 .

[22]  A. Culpepper,et al.  Weed management in glyphosate-tolerant cotton. , 1998 .