|Boykin Jr, James|
Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/11/2009
Publication Date: 5/20/2010
Citation: Reddy, K.N., Boykin Jr, J.C. 2010. Weed Control and Yield Comparisons of Twin-and Single-row Glyphosate Resistant Cotton Production Systems. Weed Technology. 24:95-101. Interpretive Summary: Research on 15-inch twin-row (narrow row) cotton production as an alternative to conventional single-row (40-inch) row cotton production in the lower Mississippi River Delta region is limited. Scientists from Southern Weed Science Research Unit and Cotton Ginning Research Unit, Stoneville, Mississippi have conducted 2-yr field studies to assess cotton canopy closure, weed control, and lint yield in 15-inch twin-row as compared to single-row pattern under irrigated environment. Cotton canopy closed 2 weeks earlier in twin-row compared to single-row pattern. Total weed dry biomass was reduced by 35% in twin-row compared to single-row pattern. Cotton grown in twin-row produced 6% higher lint yield than single-row cotton. These results demonstrated that cotton production in 15-inch twin-rows on 40-inch beds is a feasible option for farmers looking for simple production practices that increase lint yield with the benefits of narrow row pattern without increasing seed cost.
Technical Abstract: A 2-yr field study was conducted during 2007 and 2008 at Stoneville, MS, to determine the effect of twin-row (two rows 38 cm apart on 102-cm beds) and single-row (on 102-cm beds) pattern and glyphosate POST applications with and without fluometuron + S-metolachlor PRE on cotton canopy closure, weed control, and lint yield in two cultivars (‘DP117B2RF’, early maturity, hairy leaf; ‘DP164B2RF’ mid-full maturity, smooth leaf) under an irrigated environment. The experiment was conducted in a split-split plot arrangement of treatments in a randomized complete block design with row pattern as the main plot, cultivars as the subplot, and herbicide programs as the sub-subplot with four replications. Cotton canopy closed 2 wk earlier in twin-row pattern compared to single-row pattern. Canopy closure was unaffected by cultivars and herbicide programs. Control of nine predominant weeds was sufficient (=95%) to support cotton production. Total weed dry biomass was reduced by 35% in twin-row compared to single-row pattern, 15% in ‘DP117B2RF’ compared to ‘DP164B2RF’ cultivar, and =97% with glyphosate EPOST, EPOST fb MPOST, EPOST fb MPOST fb LPOST following PRE herbicides or three applications of glyphosate-POST only without PRE herbicides compared to no herbicide. Cotton grown in twin-row pattern produced 6% higher lint yield than single-row cotton. Cultivar ‘DP117B2RF’ produced 23% higher lint yield than cultivar ‘DP164B2RF’. Lint yields were higher with glyphosate EPOST fb MPOST, EPOST fb MPOST fb LPOST following PRE herbicides or three applications of glyphosate-POST only without PRE herbicides (1210 to 1230 kg/ha) compared to glyphosate EPOST following PRE herbicides (1130 kg/ha). These results demonstrated that cotton grown in twin-rows closed canopy early and produced higher lint yields than cotton grown in single-row.