Herbicide Programs for Enhanced Glyphosate-Resistant and Glufosinate-Resistant Cotton (Gossypium hirsutum)

• Published in: Weed technology 2011-10, Vol.25 (4), p.526-534
• Main Authors: Riar, Dilpreet S, Norsworthy, Jason K, Griffith, Griff M
• Format: Article
• Language: English
• Subjects: Amaranth; Cotton; Crop production; crop yield; Cultivars; Digitaria sanguinalis; Echinochloa crus-galli; Experimental research; flumioxazin; fluometuron; glufosinate; glyphosate; Gossypium hirsutum; Grass weeds; Hemp; Herbicide resistance; Herbicides; Ipomoea lacunosa; metolachlor; MSMA (herbicide); Office parks; Planting; Plants; pyrithiobac; residual weed control; Seasons; seed cotton; Sesbania; transgenic cotton; Weed control; WEED MANAGEMENT—MAJOR CROPS; Weeds
• ISSN: 0890-037X; 1550-2740
• DOI: 10.1614/WT-D-11-00027.1

Research was conducted at experimental research stations near Keiser and Marianna (Marianna-A), AR, in 2007, and in a grower's field near Marianna (Marianna-B), AR, in 2008, to compare herbicide programs, including POST application(s) of glyphosate/glufosinate alone or in combination with residual herbicides applied as PRE, mid-POST (MPOST), or layby POST-directed (PD) in enhanced glyphosate- and glufosinate-resistant cotton. Weed species evaluated included Palmer amaranth, pitted morningglory, hemp sesbania, barnyardgrass, and a mixture of large crabgrass and goosegrass. At Marianna-B, AR, the Palmer amaranth population was a mixture of glyphosate-resistant and -susceptible plants. For both cotton cultivars and at all locations, inclusion of S-metolachlor plus fluometuron PRE increased weed control and/or decreased the number of glufosinate or glyphosate applications needed in-season. At Marianna-B, AR, PRE residual herbicides and/or glufosinate were required to control glyphosate-resistant Palmer amaranth. Addition of pyrithiobac to glufosinate or glyphosate did not increase weed control. A layby PD application of flumioxazin plus MSMA was required to increase late-season control of all weed species in POST glufosinate-only programs, but not in POST glyphosate-only programs. None of the programs caused > 5% injury to either cotton cultivar. Seed-cotton yield was similar in all herbicide programs at Keiser, AR, and Marianna-A, AR, except for the POST glyphosate-only program, which yielded less than the PRE followed by POST programs in glyphosate-resistant cotton at Keiser, AR. In general, PRE herbicides did not increase cotton yield but did improve early and late-season control of glyphosate-susceptible and -resistant weeds in both cotton cultivars. Nomenclature: Flumioxazin; fluometuron; glufosinate; glyphosate; MSMA; pyrithiobac; S-metolachlor; barnyardgrass, Echinochloa crus-galli (L.) Beauv.; goosegrass, Eleusine indica (L.) Gaertn.; hemp sesbania, Sesbania herbacea (P. Mill.) McVaugh; large crabgrass, Digitaria sanguinalis (L.) Scop.; Palmer amaranth, Amaranthus palmeri S. Wats.; pitted morningglory, Ipomoea lacunosa L.; cotton, Gossypium hirsutum L.