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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #258223
Title: Weed management and cotton yield under two row spacings, conventional and conservation tillage systems utilizing conventional, glufosinate-, and glyphosate-based weed management systems

Author
item AULAKH, JATINDER - Auburn University
item Price, Andrew
item Balkcom, Kipling

Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/24/2011
Publication Date: 11/18/2011
Citation: Aulakh, J., Price, A.J., Balkcom, K.S. 2011. Weed management and cotton yield under two row spacings, conventional and conservation tillage systems utilizing conventional, glufosinate-, and glyphosate-based weed management systems. Weed Technology. 25:542-547.

Interpretive Summary: A field experiment was conducted in 2005 and 2006, to evaluate weed control in conventional, Liberty Link® (LL), and Roundup Ready® (RR) herbicide systems under standard (40 inch) and narrow (15 inch) row-spacings utilizing conventional and high-residue conservation tillage systems. There were no seed-cotton yield differences among weed management systems in 2005. The RR system produced higher seed-cotton than LL and conventional systems in 2006. Both herbicide technologies provided greater control of large crabgrass, sicklepod, smallflower morningglory and Palmer amaranth than the conventional herbicide system. No differences were observed among the weed control systems for yellow nutsedge and pitted morningglory. The RR system provided higher Palmer amaranth and large crabgrass control; the LL system provided higher sicklepod control. Thus, RoundUp® or Ignite® applied twice at two and four leaf cotton followed by a LAYBY application offers acceptable weed control regardless of row spacing and tillage system.

Technical Abstract: A field experiment was conducted in 2005 and 2006, to evaluate weed control in conventional, Liberty Link® (LL), and Roundup Ready® (RR) herbicide systems under standard [102 cm (40 inch)] and narrow [38 cm (15 inch)] row-spacings utilizing conventional and high-residue conservation tillage systems. The conventional management system included pendimethalin (0.93 kg ai ha-1) applied preemergence (PRE) followed by (fb) a split postemergence (POST) application of pyrithiobac (0.071 kg ai ha-1) at 2- and 4-leaf stages. The conventional tillage plots that included RR and LL systems also received a PRE application of pendimethalin (0.93 kg ai ha-1). Plots received two POST applications of glufosinate (0.47 kg ai ha-1) or glyphosate (1.1 kg ai ha-1), respectively, at the 2- and 4-leaf stages. A broadcast last POST (LAYBY) trifloxysulfuron (0.008 kg ai ha-1) application was applied to all 38 cm spaced cotton, while a LAYBY post directed spray (PDS) of prometryn (1.12 kg ai ha-1) and MSMA (0.597 kg ai ha-1) was applied to the 102 cm spaced cotton. Seed-cotton yield was unaffected by row spacing and tillage; however, herbicide system and year influenced seed-cotton yield. There were no seed-cotton yield differences among weed management systems in 2005. The RR system produced higher seed-cotton than LL and conventional systems in 2006. Both herbicide technologies provided greater control of large crabgrass, sicklepod, smallflower morningglory and Palmer amaranth than the conventional herbicide system. No differences were observed among the weed control systems for yellow nutsedge and pitted morningglory. The RR system provided higher Palmer amaranth and large crabgrass control; the LL system provided higher sicklepod control. Thus, glyphosate or glufosinate applied twice at two and four leaf cotton followed by a LAYBY application offers acceptable weed control regardless of row spacing and tillage system.